Yale Psychiatry Grand Rounds: "Harnessing Translational Approaches to Fight the Transgenerational Transmission of Stress"

February 09, 2024

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February 9, 2024

"Harnessing Translational Approaches to Fight the Transgenerational Transmission of Stress"

Tamar Gur, PhD, Assistant Professor of Psychiatry, Neuroscience and Obstetrics and Gynecology, The Ohio State University College of Medicine

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00:00John, for having me see, I I I did it.
00:04I didn't call you Doctor Crystal and
00:06Arena Esterlis for also reaching out,
00:08which I really appreciate it.
00:10I'll just share my slides.
00:13And so, you know,
00:16I I've come a long way for my PhD as,
00:19as you were introducing me,
00:20I was reflecting on my path.
00:21And I think one of my,
00:22one of my absolutely favorite
00:23parts of being a scientist is just
00:25going where the science takes you.
00:27And I think that's really
00:28a gift that we have,
00:29those of us who do research and
00:31our physicians as well as we just
00:33get to go where the science and
00:34our lived experience take us.
00:36So I'm very passionate about the field
00:38of reproductive psychiatry and I'm
00:40very passionate about helping women.
00:42Has the best way to help help babies, right?
00:44I appreciate all child psychiatrists,
00:46child adolescent psychiatrists.
00:48I I just really admire it.
00:50I found myself during my rotations,
00:52during not being able to
00:54compartmentalize the trauma of children.
00:56And I thought to myself the best way to
00:58help children is by helping their mothers.
00:59So that's really was the nice for my work.
01:01And so I'm really delighted to be
01:04talking to you today about the progress
01:06that we've made and I'm very pleased
01:07in fact that we've made some progress.
01:09So I'd like to start,
01:10I had the pleasure and honor of guest
01:13editing an issue of biological psychiatry.
01:15Thanks to John with Elaine Sao,
01:16who's a nationally recognized expert,
01:19really put the microbiome on the map
01:22for us in psychiatry on the exposome,
01:25the microbiome and psychiatric disorder.
01:27So this is a figure from our commentary.
01:30And when I really think about the exposome,
01:33I really think about all the things
01:35that you encounter from the womb to the
01:37grave that could impact your health.
01:39And we really see the microbiome
01:41as being a real, a real,
01:42a really key transducer of that stimuli.
01:44So illustrated here, we have diet,
01:46we have medication, we have pollution.
01:47And what I'm going to be focusing on
01:49for you today is stress and how we
01:51think of stress as part of the exposome.
01:53We all encounter,
01:55stress,
01:55everything from daily hassles to major life
01:58events to wars and things of that nature.
02:02And how can that impact us?
02:04And then how does that impact our health?
02:06And so I'd love to call all of your
02:08attention to the special issue,
02:10which really just has a number of wonderful
02:13contributions Internet from across the world,
02:15across the lifespan.
02:16Thinking about how they expose them
02:18really shapes our risk for psychiatric
02:20disorders or shapes the path that,
02:21you know, the contributes to the
02:24pathogenesis of psychiatric disorders.
02:25And so I think it's worth a download,
02:28worth a read,
02:28and I really encourage you to
02:30think about that.
02:31So as I said,
02:32I'll be focusing today on stress.
02:34So and specifically in pregnancy.
02:37So when we think about stress,
02:39what do we think about?
02:40Well, there's several layers to type,
02:42different types of stress,
02:43and I think it's important to think
02:44about each of these individually
02:45as well as collectively.
02:46So there's interpersonal stress.
02:48This is things like the amount
02:50of sleep you're able to get or
02:52if you have difficulty sleeping,
02:53whether or not you are getting
02:55a diet that's rich in fruits and
02:57vegetables and minerals and important
02:59fibers and things of that nature.
03:01Or whether you have a more deprived diet,
03:04interpersonal stressors,
03:05so your social relationships,
03:06your financial state,
03:08your your workplace or work stressors.
03:11And then there's structural
03:13and institutional things like
03:15racism can impact an individual.
03:18Things like climate change,
03:19pollution in the neighbourhood you live in,
03:22the built,
03:23you're built environment can all impact
03:25a pregnant person during pregnancy
03:26as well as the next generation.
03:29And So what I really started to
03:30think about and thinking about
03:31the special issue and just in
03:33general in my career is we can't.
03:34I can't fix all those things.
03:36We were talking before everyone
03:38came on about how it's going to
03:39be 60° today here in Columbus,
03:41OH, and I wasn't sure if that I
03:42was going to enjoy it,
03:43but I didn't know if that was a sign,
03:44a portent of our climate changing too much.
03:49But I can't change that.
03:50I do have started composting.
03:51I can't change that.
03:53But can I change personally,
03:54how these adverse exposures
03:56and their contribution,
03:57contribution to pathophysiology,
03:58Can I do anything to positively
04:01impact that in that space?
04:02If we can, as researchers,
04:04as scientists, as psychiatrists,
04:07psychologists,
04:08help the individual deal
04:10with the sequela of stress,
04:13Is that the best way of helping them?
04:15And I I happen to think so.
04:16Spoiler.
04:18And so when we think mechanistically about
04:21pregnancy and how prenatal stress is shaping
04:24the pregnancy and the next generation,
04:28why do we even think about it?
04:29Well, it used to be, though.
04:30It used to be thought, you know,
04:32women used to be told that pregnancy
04:34was just this time of elation.
04:35I guess we were thought to float
04:36around on these clouds of pink,
04:38you know,
04:38pink pheromones the entire time,
04:40blissfully awaiting our bundle of joy.
04:42But the the the case,
04:43it's not actually the case.
04:45There's actually women experience
04:46depression and anxiety at the
04:48same rate during pregnancy as
04:49they do outside of pregnancy.
04:51So up to 1/4 of women do experience either
04:54depression or anxiety during pregnancy.
04:56And I have some statistics for you here.
04:57So the reason we think about
05:00stress and sequela of stress,
05:01which is how as I conceive of
05:03depression and anxiety amidst
05:05those stress is a known trigger
05:07for many psychiatric disorders.
05:09Beyond depression and anxiety,
05:12we we it's important because it's
05:15relevant because there's prevalent
05:17and so that's why this is worth worth
05:19your time today with me this morning.
05:22You're going to encounter this at
05:23some point either in your personal
05:25or in your professional life,
05:26depending on your patient population.
05:29And so most of the focus until about
05:32a decade ago was on these mechanisms.
05:34Really stellar work from Tracy
05:36Bale and Petit Guadwa have really
05:38focused on epigenetic programming.
05:39So it's not just the genes you inherit,
05:41it's how they're expressed that can
05:42contribute to your risk of disease.
05:44So epigenetic modifications can go a
05:47long way to increasing or reducing your
05:50risk of what's in your genetic code.
05:53There's been a lot of focus
05:54on the immune function.
05:55So there's a broad epidemiological and
05:57clinical research that demonstrates
05:59that infection with the influenza
06:01during pregnancy is is known as is
06:03known to be associated with increased
06:05risk of developing schizophrenia
06:07in the offspring exposed to that.
06:09And there's other
06:12lines of evidence that also
06:14suggests that the immune system
06:15during pregnancy plays a key role
06:17in the transmission of stress.
06:19HPA access regulation.
06:20That makes sense, right?
06:22That changes in your HPA access
06:24work from Tim Oberland up in Canada
06:26has shown that the offspring
06:28born to women with depression
06:29or anxiety during pregnancy have
06:31dysregulation in their HPA access.
06:33Then about a decade ago,
06:34right as I was coming on the scene,
06:36there was some work.
06:38The new contender in this field is
06:40now the the gut brain axis is also
06:43thought to play a role in how prenatal
06:45stress might be underlying some
06:47of the mechanisms in transmission
06:48of stress to the next generation,
06:50which will be really the focus
06:52of my talk today.
06:53So when I first started
06:55giving talks in this space,
06:57I remember I was at SOBP one year.
06:59Someone asked me, you know,
07:01the brains all the way up here and you know,
07:03the guts all the way down here.
07:05How?
07:06How, You know what,
07:08how are the two connected?
07:09And so I spent a lot of time thinking
07:11about that and writing about that
07:13and making slides about that.
07:15So I'm going to explain that to you.
07:16So hopefully today you'll leave
07:18with a better understanding of
07:19how how that might be working.
07:20And so really it's a it's $1,000,000
07:23question or multi $1,000,000 question.
07:25How are peripheral changes in
07:27the microbiome And when I say
07:29microbiome with something no more,
07:31no less than all the collective
07:33community of microbes that are
07:34present in different orifices in
07:36your body and the gut microbiome
07:38specifically is thought to have an
07:40important role in your overall health.
07:43So our how are changes in your
07:45gut microbiome being transduced.
07:47And so we really think about in
07:49pregnancy three major ways that this
07:51is being transduced to the developing brain.
07:53And so this is an illustration
07:54from a review I wrote a few years
07:56back now with a very talented MD,
07:57PhD student in my lab,
07:59which we'll be hearing more about.
08:01So the three major ways are
08:03through the first of all,
08:04it's thought that stress is shifting
08:06the microbes and I'll just like
08:07to illustrate this in a moment.
08:09The three major ways is that
08:11through vertical transmission.
08:12So at delivery,
08:13not to be too graphic before lunch,
08:15but during delivery the mother
08:17bequeaths her microbiome to the infant
08:19through a standard vaginal delivery
08:21or through C-section is one way
08:23that it's thought to shape the the
08:24governing axis of the next generation.
08:26The 2nd way is through
08:28modulation of the immune system,
08:30because microbes at the end of
08:32the day are microbes and they
08:33elicit an immune response.
08:35And then through the metabolites,
08:36they're not just sitting there
08:38quietly twiddling their thumbs,
08:39they're actually producing
08:40really bio active metabolites,
08:43and I'll be talking more about that as well.
08:46So to illustrate for you this even further,
08:48we have here a pregnant person
08:50and they're undergoing stress.
08:52What happens next is that there's
08:55activation of the HPA axis, release of ACTH,
08:58release of glucocorticoids from
08:59the adrenals as well as sympathetic
09:02nervous system activation.
09:04How this impacts the host,
09:06which is the pregnant person
09:08in this illustration is it can
09:10modulate their immune system.
09:12So lead to the recruitment of immune cells
09:15and the activation of immune cells to trans.
09:20You've raised something called cytokines
09:21which if there's any immunologists,
09:22I apologize in the audience,
09:24but I I sometimes think of cytokines as
09:27the neurotransmitter of the immune system.
09:28So these can travel and recruit
09:31additional immune cells and cytokines
09:32themselves can have impact on neurons
09:35and other and other cells in your brain.
09:39And then it also all these together,
09:41both the immune system activation
09:43as well the sympathetic nervous
09:45system activation has an effect
09:47on the intestinal epithelium.
09:48And so the impact on the intestinal
09:50epithelium can also give rise to and it
09:53can also separately impact the microbes.
09:54So the idea is that during stress,
09:56there's a shift from 1 homeostatic
09:58population of microbes.
10:00There's dysbiosis.
10:01So it gives rise to a shift in the community
10:04of microbes that are present in your gut.
10:07And why is this important?
10:08Well, for a few reasons.
10:09One, as I mentioned, they're not just
10:11sitting there twiddling their thumbs.
10:12They're making metabolites.
10:13If there's anyone in the audience
10:14that wants to guess.
10:15But these are.
10:16These are two of my favorite metabolites.
10:18This is I guess actually
10:19you you you can't unmute,
10:21it's actually serotonin and butyrate
10:23which butyrate for those of you
10:26interested in epigenetics is a very
10:28important epigenetic modifier and
10:30serotonin we all we all know and
10:32love and so they're actually major
10:35metabolizers of tryptophan and
10:36producers of short chain fatty acids.
10:39So it's incredibly important These
10:41together can have an immunomodulatory impact,
10:43these metabolites as well as well as
10:47at delivery the baby is going to be
10:51seated as I mentioned by the mother.
10:52So this sets up the next generation's
10:54got brain access in a way that
10:57could be maladaptive.
10:58And then why we worry about
11:00that is because Mycoglia,
11:01which are the innate immune
11:03cells of your brain,
11:05are increasingly understood to
11:07have an incredibly important role
11:10in psychiatric disorders like
11:11anxiety and depression.
11:13So a shift in microglia,
11:14both in terms of their population
11:16as well as their level of activity
11:19could understandably contribute to the
11:20emergence of psychiatric disorders.
11:22So this is sort of the 1000 foot
11:24view or 10,000 foot view of what
11:27I'll be speaking to you about today.
11:28And I really just wanted to give you
11:30a framework in which to put all the
11:31data I'm about to present to you.
11:32So this is sort of how I conceive
11:35of the gut brain access during
11:36pregnancy and how it might be
11:39impacting the developing brain.
11:41So one of the wonderful things
11:42about working with rodents,
11:44and this is an illustration
11:46from the special issue that I
11:48co-authored with Mary Kimmel,
11:49a close friend and colleague
11:50at the University of North
11:51Carolina, Chapel Hill,
11:52is that we can test some of these things.
11:54You know, human pregnancies
11:55take nine months, give or take.
11:57Mouse pregnancies or 21 days, give or take.
11:59And we can mechanistically get AT and
12:01over using a variety of tools that
12:02I'll be showing you today some of these
12:04bigger questions on a micro scale.
12:06And so this if you're interested
12:08in reading more about this,
12:10please go ahead and look at this review.
12:11But what I wanted to highlight for
12:13you now is that I'm really going to
12:15be focusing on this shift in maternal
12:17gut microbes as well as the upper
12:19left hand portion of this figure,
12:21which is the cytokine production.
12:24CCL 2 which is a chemokine that recruits
12:26immune cells to the site of injury
12:28like a cut or is also been shown by
12:30work from a colleague here Jonathan
12:32Godbout to be really important in
12:34increasing anxiety following a stressor.
12:38So within the absence of CCL 2,
12:40I work from Godbout's lab and
12:42Michael Bailey's labs and others have
12:43shown that you no longer see the
12:45emergence of anxiety like behaviour
12:47after a social defeat stress.
12:48So it's it's a critically
12:50important chemokine.
12:51So I just wanted to give you the,
12:53the,
12:53the basic framework and the
12:55clinical framework for what what
12:57we'll be talking about today.
12:59So how again we can model this in mice.
13:01And one of the reasons that I became
13:03so interested in this field is
13:05because I saw the high translational
13:07nature of the microbiome.
13:08I saw that it was both in in mouse
13:10and man or woman in this case.
13:12And so I really thought that we could really,
13:15I could really advance the advance
13:16the field in a way that was unique
13:19because there there are limits,
13:21translatability.
13:21And so I was really drawn to the
13:23microbiome for a variety of reasons,
13:25but that was one of them.
13:26So how do we model this in mice?
13:29And I'm just going to have to move
13:31my little zoom bar here so that
13:32I can see my slide.
13:34This is how we we model it.
13:35So in our lab,
13:36we do a restraint stress,
13:37which is not that mice are placed
13:40in conical tubes with air holes for
13:42two hours a day between gestational
13:44day 10 and gestational day 16,
13:45which you can see here is roughly
13:47correlated to the second trimester in humans,
13:48which has been shown in a variety of
13:51epidemiological and clinical studies
13:52to be critically important for
13:54neurodevelopment and increasing risk
13:56of psychiatric disorders in terms of stress.
13:59And then one cohort of mice is a
14:01sacrifice at gestational day 17.
14:03Another cohort is allowed to go through
14:04parturition and an age into adulthood.
14:06We don't have a second hit in this model.
14:09It's just the only stressor they
14:11experience is in utero and then we
14:13do behavioral testing in adulthood.
14:14You can see that a few things to
14:16point out is that mouse pregnancy
14:18is besides the duration
14:19of pregnancy has other differences.
14:22So in in mice and I'll be showing
14:24you a video in a little bit,
14:26there's it's like a Pearl necklace
14:27or like a necklace like the one
14:29I'm wearing where each mouse,
14:30each fetus is individually housed with
14:33a placenta and its own amniotic SAC
14:35and and there's litter sizes between
14:378:00 and 10:00 are quite normal.
14:39Whereas obviously in humans
14:41Singleton pregnancies are the norm.
14:42Though of course there's you know
14:44twins and triplets out there and more.
14:46There's just several structural
14:48differences between the placenta as well
14:50and so there's absolutely differences.
14:53And another important difference to
14:54point out to you is that a lot of
14:57neurodevelopment occurs X utero in mice.
14:59So at post Natal day one that's roughly
15:01equivalent to the third trimester.
15:03So mice of course are not little people,
15:05but we can draw some mechanistic
15:08conclusions nevertheless from this model.
15:11So what we found,
15:12I'll tackle a few of the a few of the
15:16findings in rapid succession so that
15:18I can try to walk you through what
15:20I believe is the most exciting part,
15:22which is the translate translational
15:24nature of this research.
15:25But I'm happy to answer questions
15:27afterwards in the Q&amp;A.
15:29So the first thing that was important
15:31to establish in this model was
15:33does this stress actually change?
15:34Does it actually lead to dysbiosis,
15:36a change in the microbes?
15:38And the answer, the short answer is yes.
15:39So what I see here on the left
15:41is the is the dam,
15:43which is what we call mouse moms.
15:45And this is PCOA plot.
15:47So this is no more,
15:47no less than the entire genome,
15:49microbiome genome of a specific mouse.
15:52So each dot represents the grand
15:54sum total of the genes expressed
15:56in the microbes of the mom.
15:58And this is taken on day 17 of gestation.
16:03So after the stressor is completed
16:05and what you can see here is that
16:07there's a significant effect of stress.
16:09So red is stress, blue is control,
16:11and there's a shift in the microbiome
16:13of the dams that were exposed to
16:15prenatal stress and those that weren't.
16:17Next,
16:17I'll turn your attention to male
16:19and female offspring.
16:21And what you can see is, again,
16:22blue is control, red is stress.
16:24There's a significant shift in adulthood.
16:27So these samples were taken in adulthood.
16:30So even though they were never
16:31stressed again,
16:32just the fact that they were
16:33exposed to stress in utero gave
16:35them a significantly different
16:37microbiome into adulthood.
16:38So it really does look like the gut.
16:40Brain access was shifted in these
16:42offspring who are exposed to
16:43prenatal stress and the citations
16:45are in the bottom right hand corner.
16:47In case you're interested in
16:49reading more next I'm turning my
16:51attention to adulthood.
16:52In the interest of time I'm just going
16:53to show you social behaviour today,
16:54but we have found increased in
16:57increased anxiety like behaviour in
16:58female and changes in cognitive tasks
17:00as well in the female offspring.
17:02This changes in social behaviours were
17:04found in both male and females and we've
17:06now replicated and extended these findings.
17:08But for the purpose of today,
17:10for those of you that might not have
17:11had the pleasure of doing mouse
17:12behaviour during your training,
17:13I thought I would share a video.
17:15So this is a social approach paradigm.
17:18It's the three chamber social behaviour test.
17:19So in one of these little
17:21chambers this is a mouse.
17:22I'm blinded so I do not know if this
17:24mouse was exposed to stress or not,
17:26but it can either choose to investigate.
17:28In this little cage is either a mouse or,
17:31and in this little cage is an object,
17:33and we simply measure the amount of
17:36time prefers to spend approaching a
17:38it's a mouse from a very docile mouse.
17:40Strain a DBA mouse and of the same
17:44sex as the test mouse and it's able to
17:46poke its little nose between the bars.
17:49But it's not able to engage in aggressive
17:51or sexual behavior with a mouse or an object.
17:54And what you can see here is that
17:56I'm showing this is a heat map of
17:58where it chooses to spend time.
17:59So what you can see is that there
18:01was a significant reduction and
18:03now we've extended this to other
18:04social paradigms as well.
18:05There's a significant reduction in the
18:08social behaviour demonstrated by both
18:10male and female offspring exposed to
18:12prenatal stress compared to the control mice.
18:15And so this showed us that yes,
18:17so check there's changes in the microbiome,
18:20check there's changes in
18:22behaviours in adulthood.
18:23And the next thing we wanted to
18:24examine was that whether or not there
18:26was changes in neuroinflammation.
18:27So we did this in a number of ways.
18:29So I'm showing two of them here.
18:31We've done this now with full cytometry,
18:33immunohistochemistry as well
18:35as gene expression.
18:37And I if you invite me back in a few years,
18:39we currently are working on our single
18:40cell RNA seek data and we're finding some
18:42very exciting changes there as well.
18:44So we've now interrogated this
18:46in several different ways.
18:47What I'm showing you here is that
18:49there's a significant increase here
18:50on the left side in fetal brain
18:52gene expression of Illinois 6,
18:53which is a key cytokine that's
18:55been implicated in a variety of
18:57psychiatric disorders,
18:58including anxiety and depression.
18:59So this is in fetal brain and
19:01embryonic day 17 and then half.
19:03There's also a significant
19:04increase in TNF alpha.
19:06Next,
19:06we did immuno labeling for IBA one,
19:09which is a marker for microglia.
19:12And what we found was a significant increase
19:15in IBA one staining in the prefrontal cortex
19:18in mice taken from stress pregnancies.
19:22And compared to controls,
19:23we also looked as a control region in
19:25the motor cortex where we did not have
19:27an A priori hypothesis that we would
19:28see a change in neuro inflammation
19:30or in microglia labeling there.
19:32And in fact,
19:33we did not see an
19:34an increase there.
19:35So this isn't just global neuro inflammation,
19:37it's specific to brain regions
19:39that are implicated in behavior.
19:41And we also saw an increase in loops,
19:42IL 1 beta in that in the prefrontal cortex as
19:45well as Illinois 6 and this is an adulthood.
19:48So on the left side of the slide
19:49we have embryonic offspring.
19:50And what I'm showing you here on the right
19:52is that this continues into adulthood.
19:54So the microbiome changes
19:55continue into adulthood,
19:56the behavioural changes
19:57continue into adulthood,
19:59and neuro inflammation continue
20:01into adulthood as well.
20:03So as I mentioned,
20:05CCL 2 is an important chemokine
20:07that recruits immune cells to a
20:09site of injury or to or and also
20:12increases in response to stress.
20:14And So what we hypothesized was that,
20:16and it has been shown to be
20:18required for behavioural changes
20:19following a social defeat stressor.
20:21So then we simply set to set up,
20:22we simply set out to test whether
20:24or not CCL 2 was required for
20:27the behavioural changes and the
20:29inflammatory changes that we
20:31saw following period of stress.
20:33So to do that we took CCL 2 knockout mice,
20:35which are commercially available and
20:37constitutively have CCL 2 knocked out.
20:39And we put them through the same stress
20:42paradigm that I showed you earlier
20:44with the regular wild type mice.
20:46And the first thing we found was
20:47that there was no longer that
20:49increase in Illinois six in the
20:50fetal brains or the increase in
20:52TNF alpha in those fetal brains.
20:54And when we looked at behaviour,
20:55we no longer saw a significant reduction
20:58in social behaviour in the adult
21:01offspring following prenatal stress,
21:03which was very different than what we
21:05had seen in the wild type medicine
21:07that came out during the pandemic
21:09and translational psychiatry.
21:12So then Helen, my very talented MD,
21:14PhD student that I've mentioned
21:16who's going to match in the
21:18next month in Pediatrics,
21:19didn't succeed in recruiting
21:20her into psychiatry.
21:21But that's OK.
21:22She'll be a phenomenal pediatrician and she's
21:24still interested in the developing brain.
21:25So I'll consider that a win.
21:27I wanted to ask a daring question,
21:29which is whether or not an increase
21:31in fetal CCL 2 would be sufficient.
21:33So it's required, but is it sufficient
21:36to induce the changes that we saw?
21:38So how was she going to do that?
21:41Well, she decided.
21:44We decided that she would
21:47inject intraemniotic CCL 2,
21:49recombinant CCL 2,
21:50mouse CCL 2,
21:51or saline on embryonic day 16 1/2.
21:54She did a whole bunch of
21:56experiments leading up to this.
21:57Wish I'll spare you a time course.
21:59And we found that CCL 2 peaked on day 16.5,
22:02and so she wanted to emulate that
22:05with a injection of recombinant
22:07CCL 2 on embryonic day 16.5.
22:10And I'll show you a video in a moment
22:12to show you exactly how she did that.
22:14And then one cohort.
22:15And then she sewed the mice back up again.
22:17They recovered nicely from
22:18anaesthesia and from the surgery or.
22:20And then we one cohort we collected samples
22:23on embryonic day 17 1/2 and the other
22:26went through parturition, no problem.
22:28And then we looked at behaviour in adulthood.
22:31So for any of you who are squeamish,
22:32you might just want to look away
22:34for the next 1015 seconds or so,
22:36because what I'm going to show
22:38you is her surgery.
22:39So she would anesthetize the mice,
22:42do an incision remove.
22:43You can see this Pearl necklace,
22:45as I mentioned, of all the different fetus
22:47individually housed in their amniotic sacs.
22:49And this is her very gently
22:51and capably doing an injection.
22:52So you can see she holds it
22:54carefully with the tweezers.
22:55This has been labeled with dye so
22:56that you can see it and it's going.
22:58It's basically you could see
22:59the dye migrating from one side
23:04all the way through the other,
23:07so following and here it's coming
23:09all the way back through so and then
23:13after that she carefully taps it.
23:15There's no blood and we
23:17continue on with our day.
23:18So if you were looking away,
23:19you can look again.
23:21The exposed mouse fetuses are no
23:24no longer on screen and so we
23:25were very excited to have this
23:27work come out a couple months
23:29back in behavioural beta immunity,
23:31which is a leading journal in the
23:34field of psycho neuro immunology.
23:36And what we found is first all
23:38direct your attention here to
23:39the middle amniotic fluid.
23:40So we were thankful to see that
23:42there was a significant increase
23:43in CCL 2 in the amniotic fluid.
23:46So she successfully injected them.
23:48And then I think it's really interesting
23:50to note here on the left hand side
23:51that it stayed in the fetal compartment.
23:53There was no travelling of this
23:55protein into the maternal compartment.
23:57So we looked both at the plasma There,
23:59we looked at the maternal plasma.
24:01There was no,
24:01there was no change in CCL 2.
24:03And then we looked at the placenta.
24:05There was no increase in CCL 2.
24:07So this was really contained
24:08in the fetal compartment.
24:09When we looked at the fetal plasma,
24:10we saw a significant increase in CCL 2.
24:13We looked at the fetal liver,
24:14which we've identified as being
24:16an important source of CCL 2.
24:18I didn't have time to show you that
24:19data I originally thought and we
24:20spent about five years in the lab.
24:22So any new PIS out there don't feel bad.
24:23In my lab spent about five years worth
24:26of money trying to prove that those
24:28CCL 2 is coming from the placenta.
24:29But in fact it's not.
24:30It's actually coming from the fetal liver,
24:31which is fascinating.
24:32I don't have time to get into today,
24:35but it was up in the fetal liver
24:37when we looked at the fetal brain.
24:38It was also significantly increased and
24:41finally in so in terms of the behavior,
24:44so in what you see here on the left
24:46side side of the part of this graph
24:48in green circle of social squares
24:51object with a saline injection,
24:53there's a significant in the
24:55significant preference for engaging
24:56with a social con specific.
24:59Whereas with the CCL 2 mice they no
25:01longer had preference for social interaction.
25:03So there is a reduction in social
25:05behaviors with just this intra
25:07amniotic injection of CCL 2,
25:09which I really believe confirms our
25:12our belief or confirms our hypothesis
25:15that CCL 2 is integral to the it's an
25:18integral part of how prenatal stress
25:20is transmitting these behavioral
25:22changes to the next generation.
25:25So next I really struggled,
25:27or not.
25:28Next,
25:28this entire time I was really struggling
25:30with a question of does this translate.
25:33I'll never forget in medical school
25:35during my OBGYN rotation that the
25:37big paper came out suggesting that
25:39hormonal replacement therapy was
25:42potentially not advantageous for women.
25:45And so that a lot of the literature
25:46that had
25:47supported the use of and of course
25:49the pendulum has swung wildly back
25:50and forth a few times since then.
25:52But a lot of the literature at the
25:54time had been the world at work
25:56suggesting that hormone replacement
25:57therapy was very important.
25:58So I remember as a medical student thinking,
26:00I don't want that.
26:01I don't want to spend decades of my
26:03life doing something in mice and then
26:05bring it to clinic and find out that
26:07it's completely irrelevant in humans.
26:09And so we thought of a lot of
26:11different ways in lab to figure
26:13out whether or not it translated.
26:15And so we simultaneously collaborated with
26:18a group at UCLA who had an funded RO one.
26:22And we also launched our
26:23own clinical studies.
26:24So I'll be sharing, sharing data from both.
26:26So this is first of all,
26:27a graph of maternal health.
26:28So this is where I'm sitting right now,
26:30right in the middle of Ohio.
26:31So my kids like to say 4
26:33hours from anything good.
26:34No offense to Ohio, but right smack
26:36in the middle in Franklin County,
26:38Ohio and a priority here.
26:40Unfortunately,
26:40Ohio is right behind Mississippi in
26:43terms of morbidity and mortality during
26:46pregnancy and especially this is of
26:48concern in the African American community.
26:50So it's a major issue here in
26:52Franklin County and in fact,
26:53depression is a major issue
26:54here in Franklin County as well.
26:56And you can see that almost 20%
26:58of women here have a diagnosis of
27:00depression during pregnancy in 2022.
27:02So it's a met.
27:04Postpartum depression or prenatal
27:05depression is considered a many issue in
27:08many communities here in Franklin County.
27:10And also there's a major issue,
27:12as I mentioned,
27:13with morbidity and mortality
27:14during pregnancy.
27:14So preterm birth is a negative sequela
27:18of having depression or significant
27:20depression or anxiety during pregnancy.
27:22And there's other
27:23contributing factors to that.
27:24And the low birth weight or intriguing
27:26growth restriction is a major issue as well.
27:28So this is unfortunately a good
27:30place to study some of these,
27:32some of the issues that
27:33we're concerned about.
27:35And in addition,
27:37COVID-19 absolutely impacted
27:38the population here as it did
27:40I think throughout the world.
27:41And there was just a lot of restrictions
27:43here on who you could bring to delivery
27:46and a variety of other restrictions
27:48during pregnancies that really
27:50aggravated and stressed our patients.
27:52And so we conceived of much of the work
27:55to date in the field of the microbiome
27:58in pregnancy had one time point,
28:00so the second trimester or the 3rd trimester.
28:02And what I had grown to appreciate was that
28:05it was really the longitudinal changes
28:07in the microbiome that could be important.
28:09And so we set out to do a
28:11longitudinal study of the microbiome
28:13through pregnancy and delivery.
28:15You can see the inclusion criteria on the
28:17left and our exclusion criteria on the right.
28:19When we collected,
28:20we enrolled.
28:21So this started many years ago now I think in
28:252019, so before the
28:27pandemic at two locations.
28:28So the Campbell Hall here
28:29on the left is the rest,
28:30the OBGYN resident clinic.
28:32So these are underinsured patients,
28:35insured but underinsured
28:36members of the community.
28:38And then the member of the picture
28:39on the right is on the Kenny Road.
28:41One of the faculty practices
28:42which tends to be OU insurance
28:45or well insured patients,
28:47was on the right.
28:48And I have to take the moment to
28:50thank Teresa Teresa Regisigura,
28:51who started in my lab as an undergraduate
28:53and is now completing a short postdoc
28:55in my lab as she applies for postdocs.
28:57If anyone on the call is interested in a
28:59really talented postdoctoral researcher,
29:01let me know.
29:03She's interested in going to the East Coast.
29:05And then the person on the right
29:06is my my wonderful husband,
29:08who is the world's tallest
29:10gynecologist at six foot 10,
29:11but also a really hard worker and
29:14collected all of these samples by hand,
29:16as it were that I'm about to show you.
29:18And so he was the faculty member at
29:20the practice that was collecting and
29:22he also overseas the resident clinic.
29:23So he was collecting samples at both places,
29:25which gave us a really cleanly
29:28gathered sample set to my my
29:32my deep gratitude for them.
29:35So what?
29:35I just want to shift your attention
29:36and give you some background about
29:38the human maternal microbiome.
29:39So I've shown you some data from mice.
29:41But just speaking in,
29:42in generalities, in terms of the gut,
29:44greater diversity is generally
29:47seen as beneficial.
29:49And a lot of this work, however,
29:50has come from C Clostridium difficile,
29:53which is a terrible, terrible once,
29:55if you ever encountered it clinically,
29:56you'll never forget it.
29:57Terrible, terrible form of diarrhoea.
30:00And so C diff happens when a
30:02patient has been treated with
30:03antibiotics in the hospital.
30:05So what we know about diversity in
30:07the gut is actually somewhat flawed
30:09in the sense that a lot of the
30:10literature comes from antibiotic use
30:12and that's not exactly what we're
30:14seeing necessarily out in the community.
30:16But in general,
30:16a greater diversity is seen as being
30:19beneficial and there's also known
30:20to be shifts in composition across
30:23pregnancy under normal conditions,
30:24under normal pregnancy conditions.
30:26And I have some citations for
30:27you in the bottom right there.
30:29When we turn our attention
30:31to the vaginal microbiome,
30:32diversity is actually decreased
30:34about across pregnancy and a
30:36more diverse vaginal microbiome
30:38community can actually increase
30:40risk of adverse OB outcomes.
30:42So less diversity in the
30:44vaginal microbiome community.
30:45So just there's a lot of Lactobacillus
30:47in the vaginal community and
30:49that's seen as beneficial.
30:51So there's a difference
30:52already between the gut and the
30:54vaginal microbiome community.
30:56But what we were trying to ask is
30:58how does stress impact this and
30:59really does it impact both the
31:01gut and the vaginal community?
31:03And how might this be impacting
31:06the community that the infant
31:07is exposed to at our
31:08tradition And unfortunately we did not
31:10have because of the pandemic coming in
31:11the midst of the study we did, we had.
31:13So I won't be able to answer
31:15for you today with this study.
31:16What's going on in the infant
31:17though we do have a collaboration,
31:18so I'll be able to give you some
31:20insight about the impact on the infant.
31:22So this is again our study design.
31:23We what we lacked for in sample size,
31:26we tried to make up for in again this
31:28is a pilot study we made-up for in the
31:30longitudinal nature of this study.
31:31So first, second, third,
31:33trimester delivery and nest,
31:34if when possible, postpartum visits.
31:37So the these are the study visits,
31:38these are the psychometric scales
31:40we obtained and these are the
31:41biospecimens that we obtained at these.
31:43And so we've got both rectal
31:45and vaginal swabs.
31:45Microbiome can be collected
31:47in all sorts of ways.
31:49Many studies use at home kits.
31:51I had some concerns about that
31:53for a variety of reasons I'm
31:54happy to get into in AQ and A.
31:55And so we just decided that my
31:57husband would have to collect all
31:58the samples and that worked out
32:00just fine for this pilot study
32:01and he did the rectal and vaginal
32:03swabs himself and then we obtained
32:05maternal blood and umbilical
32:07cord blood as demonstrated here.
32:09And so just for a moment about
32:11our sample demographics,
32:11we are very pleased There's been a
32:14historical exclusion of people of
32:15color from biomedical research and
32:17we were very pleased that we were
32:19able to recruit and study non weight
32:22individuals as well as reflected here.
32:24And you can see overall as I
32:25mentioned into the pilot study.
32:26So we have a small number of people,
32:28but the fact that we're able
32:29to get a signal from that,
32:30as I'll show you shortly,
32:32was we're still able to get a
32:34signal from even a small sample size
32:37suggesting that we are on to something.
32:39So we got stress scores and
32:42depression scores.
32:42And what you can see here is this
32:44is the scale of PSS and CSD.
32:46If you're not familiar with them,
32:48low is 0 to 13.
32:49So these were not,
32:52they were not clinically
32:54depressed individuals in general.
32:57So this is just all
32:59comers to an OBGYN clinic.
33:00These were not psychiatric
33:01patients coming to for psychiatric
33:03care or psychological care.
33:05So we really were setting out to ask
33:07if stress and depressive symptoms
33:08are associated with differential
33:10abundance of specific maternal
33:12microbial taxes or specific microbes.
33:15And So what we found is that there was
33:18in the third trimester Lactobacillus
33:20specifically Lactobacillus einers
33:23was significantly shifted with
33:26with stress and this was actually
33:28contrary to general expectation.
33:30They're generally thought to be beneficial.
33:32So this we were intrigued to see
33:34this and we also found that these
33:36are also known to be a dominant
33:38tax of the vaginal community
33:39especially during pregnancy.
33:40So as I mentioned Lactobacillus
33:43is a major vaginal microbe.
33:45And so one of the ways that preterm
33:47birth is thought of just in the
33:50obstetrical community is that
33:52others maturation is happens more
33:54rapidly both in the brain and
33:56the lungs and potentially what
33:57we're seeing here in the in the in
34:01the vaginal and gut microbiome.
34:03And so the idea is that preterm birth
34:06happens for for still unknown reasons,
34:08but part of what's seen in preterm
34:10birth is that the fetus and the the
34:14maternal pregnancy mature more rapidly.
34:16So is that in fact,
34:17maybe what we're seeing here is that
34:19there's an earlier migration of
34:21vaginal microbes to the gut microbiomes.
34:22That's that's something we're
34:24interested at in pursuing.
34:25At delivery,
34:26we saw a significant increase
34:28in these microbes,
34:29which are in fact pathogenic and
34:32associated with gestational complications
34:34as well as intrauterine inflammation.
34:36So we were interested to see a
34:39significant increase of those with
34:41stress at delivery and Gardinella is
34:44also associated with complications
34:47and we were also interested in to see
34:49an increase in Gardinella Gardinarella.
34:51Next,
34:52when we turn our attention to the plasma
34:56CCL 2 that the chemokine that I kept
34:58talking about in my mouse studies,
35:00we actually did a panel for a
35:02variety of inflammatory factors,
35:04some of which I'm showing you here.
35:05And yet CCL 2 emerged as being
35:09associated with stress and depressive
35:11symptoms in the third trimester.
35:12So I was very fascinated to see
35:15that this chemokine that plays such
35:17an important role in rodent models
35:19of stress was also here in humans.
35:21So it was associated with
35:23significant increases.
35:24So this is maternal plasma
35:27in the third trimester.
35:29So just to summarize,
35:30what I'm showing you so far is
35:31that an increase in stress and
35:33depressive scores was associated
35:34with an increase in maternal CCL 2.
35:36Next,
35:37when we looked at CCL 2 and its
35:39relationship to Lactobacillus,
35:41we were very heartened to see that
35:43there was a a relationship between these two.
35:46So in an extended previous findings
35:48that Lactobacilli are found in
35:50greater abundance and infants
35:51of mothers with lower prenatal
35:53anxiety and depression.
35:54So again if Lactobacillus is beneficial,
35:57it's very interesting that the
36:00more Lactobacillus there was the
36:02less CCL 2.
36:02So that extends our previous findings.
36:06So in summary, increased stress
36:07and depression. I'm sorry,
36:09I'm struggling to move this zoom bar.
36:11Increased stress and depressive
36:13scores were increased associated with
36:16increased maternal CCL 2 and umbilical
36:18CCL 2 and a reduction in lactobacilli.
36:22And again, this is exciting to me personally
36:24because this is mirroring what we were
36:26seeing in our rodent model as well,
36:28suggesting that we have found something
36:30that is translatable and important.
36:32It wasn't just in mice that we were
36:34starting to see signals that it
36:35could be important in humans as well.
36:39So this is what I've been showing you
36:42now in humans that there's an increase
36:44in natively vaginal taxon opportunistic
36:46pathogens just in the small pilot study,
36:48an increase.
36:49You know,
36:50there's a relationship between
36:52psychometric scores and maternal
36:53CCL 2 in the third trimester.
36:55And finally in AD delivery.
36:57There's also this relationship
36:59between CCL 2 and lactobacilli.
37:01So it really looks like we've hit upon
37:03something that we might be able to target,
37:05which of course my,
37:07my,
37:07my hope and my dream and my goal
37:09as a psychiatrist is to actually
37:10be able to target something that
37:13will help my patients endure stress
37:15during pregnancy and overcome it.
37:17So I want to shift our attention a
37:20little bit to microbial metabolites,
37:22which as you'll remember from
37:23the beginning of my talk,
37:24we think is an important way that
37:26the microbiome is transmitted
37:27to the next generation.
37:29So I want to focus on a particular
37:31metabolite, which is tryptophan.
37:33And so tryptophan has a very
37:35mixed history in psychiatry.
37:37It's been tried over the years to
37:40cure a variety low tryptophan diets
37:42have been tried high tryptophan
37:43diets with mixed results.
37:45And So what we think is that in in my
37:47lab is that this one of the reasons
37:49that there might be mixed results
37:51is because there might be a lack of,
37:53there is a lack of consideration for the
37:55microbes that might be metabolizing it.
37:57So if you're giving a boatload of
37:59tryptophan to an individual who has a
38:01lower level of tryptophan metabolizers,
38:03they might not be using it and
38:04utilizing it in the same way that an
38:07individual with a healthy number of
38:08tryptophan metabolizers might be able to.
38:10So the hypothesis that we're going
38:12to be testing in the last portion
38:14of my talk is that maternal stress
38:16is reducing tryptophan metabolizers
38:17in a way that shifts,
38:19that disregulates the production
38:20of really key metabolites.
38:22Here in red are some metabolites that are
38:25known to be neurotoxic or Mal disadvantage,
38:27disadvantageous for your health.
38:29And in green on the right are some
38:32beneficial tryptophan metabolites.
38:33And it gets a little bit confusing.
38:34So don't worry,
38:35I'll be helping you remember
38:37all your serotonin metabolism.
38:39So that's our hypothesis that prenatal
38:42stress might be influencing neurodevelopment
38:44through changes in metabolism.
38:46And so how do we go ahead and test that?
38:48So the tryptophan story
38:49again is complex and has a
38:51missed mixed history in psychiatry.
38:52But just to refresh your memory,
38:54the majority of the tryptophan,
38:56virtually all of it comes from
38:58your diet and it's either taken
39:00up by enterocytes in your gut,
39:02you as the host or it's
39:03metabolized by gut microbes.
39:04And it's thought that might the gut
39:07microbes are metabolizing tryptophan
39:08differently than the host is.
39:10So the metabolites of kind of tryptophan,
39:12Probably the most famous is serotonin,
39:15which of course is important in adulthood,
39:17but in the fetus is incredibly important
39:19for things like external migration,
39:21sceptogenesis just of a host
39:24of different mental processes.
39:26And then kinuranine,
39:27which is known to have a role
39:28in immune function and indulse,
39:30which is known to be anti-inflammatory
39:31and associated with health.
39:33And of note,
39:34microbes in terms of producing
39:35indulse is the major source,
39:37if not the only source of indulse.
39:38It's a little bit of a controversy.
39:40Every field has its controversy.
39:41This is one of the controversies
39:43in the field.
39:45So I'm going to be focusing now
39:46on some of these key metabolites.
39:48And so we were excited to see
39:51this is a few years ago now and
39:53pictured here is Jeff Galley,
39:54who's a really talented
39:56research scientist in my group.
39:58We were excited to see that on
40:00a collaboration we had with
40:01Chris Dunkel shedder at UCLA,
40:02which I mentioned earlier,
40:04Bifidobacteria dentium,
40:05which is a major triptophan metabolizer,
40:08this is AR1.
40:09They had funded to look
40:11at maternal infant dyads.
40:13They were very generous and sent us
40:16all their samples from the infant.
40:18So these are now infants.
40:20We're examining the infant's
40:22microbiome that were sent to us,
40:24and then looking back and looking at
40:26the relationship to maternal anxiety
40:28and depression during pregnancy.
40:30And what we found was that there
40:32was a significant reduction in
40:34bifidobacteria dentium in infants
40:36born to mothers with higher levels of
40:39depression and anxiety during pregnancy.
40:41And we were excited about that
40:42because we have been seeing for
40:44several years in our mouth studies
40:45that there's a significant reduction.
40:47And I'll point your attention
40:49here to the central figure,
40:51but we've now shown this over and
40:53over again that there's a significant
40:55reduction in Paracetarella,
40:56which is another major tryptophan
40:57metabolizer in our mouse model.
40:59So we now had two converging
41:00lines of evidence,
41:01one from humans collected across
41:02the country as well as our mice
41:05here in Ohio that tryptophan
41:07metabolizers were significantly
41:08reduced with stress during pregnancy.
41:10And so we also looked at,
41:15so if there's a reduction in metabolizers,
41:16is there an increase in tryptophan
41:18because it's not being,
41:19it's not being metabolized.
41:20The short answer is yes.
41:21This is now content from the maternal gut,
41:24the ileal content.
41:25There's a significant increase
41:26with stress of tryptophan,
41:27which dovetails nicely with that.
41:29And so we went ahead and looked
41:32at Bifidobacterium in our mice
41:33and what we found is there's a
41:35significant reduction into adulthood.
41:37So these are now offspring at
41:40week three-week four and week 5,
41:41which is adolescence and we
41:43continue to see a a significant
41:44reduction of this in mice.
41:46So again, we're seeing it in humans,
41:49in infants and we're also seeing it in in,
41:52in rodent offspring that there's a
41:54significant reduction in stress.
41:55And this is also true for the Parasiterella.
41:58So in two major electric treatment
42:00metabolizers we're seeing in the
42:02reduction during pregnancy as
42:04well as during the services here
42:05in the mothers and then we're
42:07also seeing it in the offspring.
42:09So we decided to focus on this.
42:11We looked at other aspects
42:13of tryptophan metabolism.
42:14So just to refresh everyone's memory,
42:16this is the the pathway so
42:18tryptophan can be metabolized to
42:20serotonin or kinurine and then
42:22go down the kinurine pathway.
42:24And what we're finding is I'm
42:25showing you here data that there's
42:27changes in the different enzymes.
42:29So these are increased with stress.
42:31You can see here in the maternal
42:33colon as well as in the placenta.
42:35There's also changes in the
42:37arrow hydrocarbon receptor,
42:39which is mediated by the change
42:41in tryptophan metabolite.
42:42So it really looks like we're on
42:44several key aspects of this pathway.
42:46We are seeing shifts.
42:47So I'm just trying to explain to
42:49you that there's shifts not just
42:50in tryptophan but as well as the
42:52enzymes that are metabolizing
42:53it and in several key locations,
42:55including the gut,
42:56the placenta and in the colon.
43:00We then looked in the fetal brain
43:02because we wanted to see if there
43:03was a shift there as well.
43:04And the short answer is yes.
43:05I'm not reminding you that tryptophan
43:08goes into the cells through transporters.
43:10And all along this pathway
43:12illustrated here on the right,
43:13we're seeing significant changes in
43:16tryptophan related gene expression.
43:18So this is all gene expression data
43:21from the fenial brain on embryonic day 17.
43:24So it's disrupted now.
43:25I'm now showing you it both on
43:27the maternal side and the placenta
43:29as well as in the fetal brain.
43:30So we decided to continue on this pathway.
43:33So what I've shown you so fire is
43:35that there's changes in tryptophan
43:37with maternal stress.
43:38And then we're looking at these
43:39metabolites and this is pilot data
43:41that we're actively replicating.
43:42But it does look like, yes,
43:44there's a significant increase in
43:47these more toxic metabolites in
43:50both the fetal plasma as well as
43:52in the ileal content of the fetus.
43:54And So what I think that the one
43:57of the exciting but also complex
43:59things that
43:59we face is that it's not just I can't,
44:01we can't just think of things as good,
44:02as bad it, but it's really the dysregulation.
44:04So even cytokines aren't just good or bad,
44:06but it's the dysregulation of the cytokine.
44:08And I don't think tryptophan is
44:09either good or bad, but it's,
44:11it's dysregulation and the shifting of
44:13the balance of its metabolites that we
44:15think might be shaping neurodevelopment.
44:17And so just to remind you,
44:19I showed you now it seems like
44:21lifetime ago there is a significant
44:23increase in neuroinflammation,
44:24which is the bottom part
44:26of this hypothesis here.
44:27So we are seeing key checks,
44:29checkpoints being met here
44:32along our hypothesis.
44:33So we really wanted to ask
44:35can we orchestrate this?
44:36Can we take advantage of what we're seeing
44:39and try to target this with the long
44:41term goal of bringing this to clinic.
44:43And so of course we have to start in mice,
44:45but if maternal stress is
44:47changing tryptophan metabolizers,
44:48can we then address this and shifting
44:52the balance towards more neurotoxic or
44:55less maladaptive tryptophan metabolites
44:57and this is impacting neuroinflammation.
44:59Can we hear,
45:01buffer the pregnancy in the developing
45:03fetus in a way that would be beneficial?
45:06And just to remind you that we do
45:08see changes in the HR which is the,
45:10among other things is a receptor
45:12for these metabolites.
45:12So This is why we're driven to
45:14do the following experiment.
45:16So what we did is we took our regular
45:19model of stress and we added a probiotic
45:21so that mice were administered A probiotic.
45:23I'll be showing you data
45:25both from parasitorella,
45:26which again we had seen reduced
45:27in the mouse pregnancies,
45:28and Bifido bacteria redemption,
45:29which we had seen reduced in human
45:32pregnancies and then we replaced it.
45:33So if it's reduced, simple question.
45:35If it goes down with stress,
45:36if we give it back,
45:38can we benefit some of the outcomes
45:40I've shown you in the course of my talk?
45:42And so the first thing that's
45:44important to me is whether or
45:45not it's going to stick around.
45:46So spoiler alert,
45:47if you go to Whole Foods and
45:48buy some probiotics,
45:49probably going to go right through you.
45:50If I were to do an experiment
45:53similar to this for you,
45:54you wouldn't see any change because it's
45:56actually they would just pass through.
45:58So that's part of why we were
46:00givaging and that's why we repeatedly
46:01administrated it as we really wanted
46:03it to stick around during this critical
46:05neurodevelopmental time points.
46:06So yes,
46:07you can see here that administration
46:09of Bifidobacterium dentium.
46:10We then looked at the colonic stool,
46:12it stuck around,
46:12which is critically important
46:14to us in this experiment.
46:15Next we wanted to see if it was beneficial.
46:18And you think four years into
46:20this pandemic I wouldn't be
46:21struggling with this silly zoom bar,
46:23but it's literally over my graph
46:25and I cannot
46:27move it, so I can't see what this graph says.
46:30Here we go. This is one of the important
46:34findings is that we have consistently
46:35seen and one of the ways we know that
46:38we're stressing the animals is that
46:39we see a change in weight even when
46:41we standardize it to litter size.
46:43So when we look at the weight gain
46:46of the dams of the rodent moms,
46:47significant weight loss or lack of
46:49weight gain is what we find with stress.
46:51And what we found is that when
46:53we administered Bifida bacteria,
46:54dentium, this was ameliorated.
46:55So we were very excited about that.
46:57Nothing we've ever done in the
46:58course of our lab work has ever
47:01prevented this weight loss.
47:02So this is really positive in our opinion.
47:05And then we also saw a significant
47:07reduction of levels of CCL 2 in the
47:10maternal plasma with the administration
47:11of Bifida bacteria dentium.
47:13Next we looked at the liver and we and
47:15this is now switching to parasitorella.
47:17We found a significant effect of
47:19parasitorella in both the fetal liver
47:21as well in the as well as the fetal
47:23grain in terms of reducing Illinois 6.
47:25And then finally and most importantly
47:28perhaps is that the reduction in social
47:31behavior that we see with stress was
47:33ameliorated as well in in females,
47:36not in males,
47:37which I'm happy to discuss during the Q&amp;A.
47:39But we saw a significant,
47:41we saw a significant amelioration of that.
47:43So they won't,
47:44they went back to preferring to engage
47:46with a social with a con specific
47:48with another rodent over an object.
47:50Next we're turning our attention
47:52to some of these metabolites.
47:53So again to remind you here on the
47:55left kineric acid is thought to be
47:57beneficial and we saw a significant
47:58increase kryonic acid in the maternal
48:00plasma here on the left as and we
48:03saw a significant increase with
48:05Parasiterella in the fetal plasma
48:07of another beneficial metabolite
48:09which is Indo 3 acetic acid.
48:11So we were very excited about
48:13that and finally can urinate in
48:15the maternal ileal content.
48:17What we saw,
48:19we saw that Parasiterella reversed the
48:21significant increase of that with stress,
48:23which is very promising.
48:25And then finally Tryptophan school was
48:28normalized with the treatment of with
48:30paracettorella in the maternal gut content.
48:32So it really does appear that we have
48:35hit on a translatable target that we
48:38can then work to prevent the negative
48:40sequela of stress during pregnancy.
48:43So this is my main conclusion.
48:45I haven't wasted a decade of my life,
48:46which is quite the relief.
48:48But more seriously,
48:51there's both converging preclinical and
48:53clinical evidence that prenatal stress,
48:55it is associated with ultra microbiome
48:57in both human and rodent pregnancies on
48:58the mom as well as in the offspring.
49:01We have evidence that CCL 2 is a key
49:04factor in all of this and is both
49:06influenced by stress and the microbiome.
49:08And at least in in rodent we
49:10have shown that
49:11it is sufficient to induce changes.
49:13And in humans we are seeing an
49:14emerging signal that it might also be
49:16influenced by stress and potentially
49:18playing a role there as well.
49:19And that I hopefully have uncovered
49:21something that could be a translational
49:23target for me to focus on in
49:24this next a decade of my career.
49:26With that, I'll stop and I would
49:30wouldn't be a good talk without thanking
49:31the wonderful members of my lab.
49:33I feel really lucky to work with
49:34some really bright, dedicated
49:37scientists. I'd like to thank my husband
49:39again for manually collecting all the
49:41samples I showed you from our study, as well
49:43as and generally being very supportive.
49:45My mentor, Mike Bailey,
49:46who's at Nationwide Children's Hospital
49:48who taught me everything I Googled,
49:49I googled Ohio State stress
49:51microbiome back in 20, 14.
49:53And his name came up and I called,
49:55emailed him and he's been a
49:57wonderful mentor ever since.
49:58And then, of course,
49:59I'd love to thank my fund,
50:01my funding sources,
50:01and then all of you for your time,
50:04thank you for listening to me today.