Professor of microbiology and researcher Dr. Anne Estes talks with Adriana about how your gut microbiome (not just your vaginal microbiome) plays a critical role in seeding your baby’s microbiome during birth, and what you can do about it. They discuss whether probiotics are necessary during pregnancy, why inserting a garlic clove in your vagina may not be the best way to combat Group B Strep, and the importance of looking at microbiomes through a diversity lens.
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- Antibiotic Use for Group B Strep + Moms Lowers Infant Microbe Diversity, Mostly Microbes blog
- The Vaginal Microbiome: “Healthy” Differs with Ethnicity, Mostly Microbes blog
- The Evidence on: Group B Strep, Evidence Based Birth
- How our microbes make us who we are, TED Talk by Rob Knight (the microbiologist mentioned by Anne who swabbed his daughter after she was born via cesarean birth)
- How to give a C-section baby the potential benefits of vaginal birth, ScienceMag
- Maria Gloria Dominguez Bello, researcher mentioned by Anne who studies vaginal seeding (and is mentioned in the previous article!)
- The Superhero in the Vagina, The Atlantic (with info about the Lactin-V)
- Microbiome Therapy Protects Against Recurrent Bacterial Vaginosis: Reducing This Common Infection Could Help Prevent HIV and Preterm Birth, University of California-San Francisco
- Randomized Trial of Lactin-V to Prevent Recurrence of Bacterial Vaginosis, The New England Journal of Medicine
- Sustained effect of LACTIN-V (Lactobacillus crispatus CTV-05) on genital immunology following standard bacterial vaginosis treatment: results from a randomised, placebo-controlled trial, The Lancet Microbe
- Rectal and Vaginal Eradication of Streptococcus agalactiae (GBS) in Pregnant Women by Using Lactobacillus salivarius CECT 9145, A Target-specific Probiotic Strain, Nutrients
- Lactobacillus iners: a Marker of Changes in the Vaginal Flora?, Journal of Clinical Microbiology
- Contribution of Lactobacillus iners to Vaginal Health and Diseases: A Systematic Review, Frontiers in Cellular and Infection Microbiology
- Race, the Vaginal Microbiome, and Spontaneous Preterm Birth, mSystems
- The association between ethnicity and vaginal microbiota composition in Amsterdam, the Netherlands, PLoS ONE
- Changes in the vaginal microbiota across a gradient of urbanization, Nature
Related Birthful episodes:
What Does Your Poop Have to Do With Your Baby’s Microbiome?
Adriana Lozada: Welcome to Birthful, Mighty Parent or Parent-to-Be. I’m Adriana Lozada.
And for this next episode in our Nourishment and Nutrition series, we’re going to explore how what you eat during pregnancy can end up impacting your baby’s microbiome, and after hearing what my guest has to say, you may not be as worried about pooping during childbirth.
Now if you have listened to the other episodes in this series, y’know I’m practically on a quest to figure out if there’s anything you can do proactively during pregnancy, or even before then, to help you you minimize your chances of Group B Strep colonization, and of course I couldn’t pass up the opportunity to ask a microbiologist about this. I mean who better, right?
The microbiologist in question is Dr. Anne Estes who aside from being an assistant professor, microbiome researcher and mother of two, is also— as she says— the human host of the blog Mostly Microbes. In her blog, Anne helps distinguish research findings from hype, focusing on the microbiome, especially from pregnancy through the first five years of life, because she feels this is the time when we can make the biggest microbial heath.
In our conversation, Anne will be sharing a bit about how your baby’s microbiome gets seeded, we’ll ponder if microbes have anything to do with pregnancy cravings, and we’ll have a very interesting conversation about how ethnicity can affect the microbiome.
You’re listening to Birthful, here to inform your intuition.
Adriana: Welcome, Anne. I am so happy to have you here.
Anne Estes: Oh, thank you. It’s great to be here.
Adriana: Yay! And so you’ve been surrounded in, analyzing, and looking at microbes for quite a long time.
Anne: I have! I’ve always been fascinated with how microbes influence their […] hosts.
Adriana: We’ve been hearing a lot about birth in the microbiome, but what about the seeding of the microbiome during pregnancy itself? What can you tell us about that?
Anne: Yeah. So I wanted to back up one step first and start with… we’re talking about when we say “microbiome,” y’know, that is such a vague term. So really, what we’re talking about today is… we’ll be talking about, y’know, the vaginal microbiome, which is one set of microbes that are very unique, versus the gut microbiome, which is also a totally different set of microbes.
It’s very unique and separate from the vaginal microbiome. And then you’ve even got a breast microbiome, milk microbiome. You’ve got, y’know, microbiomes everywhere. So what you’re referring to with the seeding is the idea that, a lot of times— I’m sure all your listeners know this, but just to get us all on the same page— we started seeing that when babies are born in a C-section instead of vaginally, they had very different microbiome. And this also seemed to correlate with increased obesity and the allergies and asthma and all these other things, and diabetes.
So, what happened? I’m not sure if this is the exact origin story or… but I’m pretty sure it is. One of the lead microbiome researchers, Rob Knight, who’s out in California, his wife had an emergency C-section and he had been doing enough research and knew about this difference in the microbiota between C-section babies and vaginal babies. And so the way he tells the story, they had an emergency C-section after making all these plans for vaginal birth, And when they had to have an emergency C-section, he always has cotton swabs in his bag because he’s a dorky microbiologist— I mean, that’s… we have all sorts of crazy things we carry around, right? So he immediately told his wife what he wanted to do was to swab her vagina and then cover the baby.
So as soon as the doctors left the room, they started swabbing their infant girl and it took them hours, but they finally felt like they had swarmed her effectively. And they’ve— because again, he’s really excited about microbiome, where he’s tracked himself and his wife and his daughter for quite some time now, and I don’t think he’s published that data— but he’s talked about it several times. So anyway, after that, then [Maria Gloria Dominguez-Bello] has started actually doing more work looking at… she’s done proof of principles of vaginal seeding.
So the idea is that when you have a C-section baby, you incubate a swab in mom’s vagina for an hour before C-section. And then when the baby comes out, you swab their mouth, you swab their ears, nose, everything, and then full body, in trying to mimic that vaginal birth. Of course, you’re not truly mimicking vaginal birth because you’re missing the hormones, you’re missing the squeezing and missing so many other aspects that we still don’t know about birth— and so those things could also be playing into why we have different microbiomes. But the idea with seeding is that maybe you’ll try and replace some of the difference between a C-section and vaginal birth.
And of course, that’s also talking about scheduled C-sections. With emergency C-sections, what we’re seeing is that, a lot of times these are pretty far along in labor when they happen. And so it seems, either the water’s already broken or, again, perhaps it’s these hormone differences or squeezing or whatever emergency C-section infants do have microbiomes more similar to that of vaginally-born infants.
So there is something to be said for it’s really not just the procedure of C-section, but it seems like it’s the process of labor that’s important as well. What do I think of the seeding: I think as long as people… I think, in the U.S., we really are very careful about screening for Group B Strep, which is, quite honestly, pretty rare in terms of causing complications, but because when it does cause complications, they are so dramatic, we want to be really cautious with that. So as long as mom’s getting screened for it and she’s talked to her doctor and he was like that, I can completely understand vaginal seeding.
Adriana: And so I think what I was trying to get at— I love that you went through all that information because yeah, you have to know, because it is totally important to know that the difference and that there’s research being done out there to try to figure out how to even make this a protocol— but I think I was trying to go back to, while still pregnant, we used to think that the placenta was this great filter, and now we know that it filters some things, it’s sort of, it’s still fantastic and great, and, y’know, super mighty, but it does let a lot of things go through because it’s a symbiotic environment, right?
So at that point, my understanding is that there is some seeding of the baby’s microbiome by just being in, inside the body, being, y’know, through the placenta in the womb. Can you talk to us about that part?
Anne: So that research… I think the majority of microbiome scientists do not feel comfortable thinking that seeding occurs with the infant in-utero. The data really aren’t strong enough yet to say that the placenta has a microbiome in healthy babies and that this happens in-utero.
I honestly— from the different data that I’ve looked at and from conversations with a number of people— I’m still most comfortable thinking about the idea that the baby primarily gets their bacteria at birth. So, y’know, there probably is a little bit because the meconium seems to have something, but at the same time, we could be biased by the techniques we’re using because with the— and I’m not going to get into the details to techniques, but yeah— there’s, when you don’t have much DNA to sample, which would be the case in the meconium, you’re more likely to get false positives, to get something that “is” there when it truly isn’t. So I think the jury is still out. And if anything is still leaning towards the placenta, not being inhabited by microbes or a place for microbes to cross through during a healthy birth, it might be different in preterm birth.
Adriana: Interesting. Okay! So that, like, tears apart my knowledge… It doesn’t completely tear it apart, but it… but so then it narrows the focus more in that since baby’s microbiome is being seeded during a vaginal birth mainly, right, that that would be the ideal seeding, and such seeding has to do with the vaginal microbiome…
What can they do during pregnancy? Or is there anything? Or is there a point to them doing anything during pregnancy to have, like, the most optimal vaginal microbiome for that moment?
Anne: Well, yeah. Fabulous questions. I don’t think it tears your ideas apart at all. I think it’s just a switch in the way of thinking about it, because, really, the microbiome we can control probably the most is our gut microbiome. And it’s the one that we know the most about. And when everybody talks about vaginal seeding and seeding of babies and infants, they focus on just the vagina. But I can’t tell you how many different comments and things I’ve heard from different women saying that one of their greatest fears is pooping on the delivery table. And, y’know, as a biologist, like, poop doesn’t bother me. I work with dung beetles, so that wasn’t ever one of my concerns, but as a mom, and then also in starting to think more about birth and talking to doula friends, y’know, the baby comes out…
It— unless it’s my baby, which both my babies were sunny side up— but babies generally rotate so that their mouth and nose are at the anus. And they’re picking up bacteria from poop from the GI tract too. They’re not just picking up vaginal bacteria, they’re picking up stuff from your gut and that’s what we can really do the most about.
So that’s where they can be paying attention to, y’know, what they’re eating and, going back to the good ol’, what mom told you, which was the fruits and vegetables and things like that, and fermented foods. So, I still think that diet is one of the most important things that women can do to have a healthy microbiome for themselves and their baby, and start the baby off right.
Adriana: Okay. Wow. That… I… my mind is being blown again.
Anne: Yeah, welcome to the world of microbiomes!
Adriana: Now we’re thinking about poop.
So what should people be considering or paying attention to during pregnancy, y’know, looking forward to that better seeding during the birth?
Anne: So there are some really interesting studies going back to the gut microbiome work, where your gut microbiome changes dramatically, depending on if you’re eating fruits and vegetables or a vegan diet even, versus meats and cheeses and lots of dairy.
And honestly, all of your different microbes need a variety of foods. They don’t need just one or just the other, because a lot of your E. coli that actually are helpful and produce some of the vitamins we need— like Vitamin B and vitamin… some of the B vitamins and Vitamin K— those actually use meat and cheeses to make those vitamins. So, just going on one kind of diet extreme and the other is not a good thing, I don’t think, from my reading, but just having a balanced diet and leaning more heavily to your plant-based, unprocessed food, like, y’know, cooked vegetables or steamed vegetables, or even raw vegetables, but just getting away from the hyper-processed stuff that I think most of us find easiest to find in high abundance and cheaply, right? But then also feeding on fermented foods as well.
Adriana: Which is a whole other fascinating topic. What about supplementation with, like, probiotics or prebiotics during pregnancy?
Anne: Yeah. That’s a fabulous question. So your prebiotics, in my mind, are fruits and veggies— y’know, it’s what you’re feeding your microbiome. So, y’know, for my kids, like my oldest, both of them started off really well as toddlers, in eating anything and everything. And their care providers were always shocked that they would eat spinach with cumin and things like that.
But that’s just what they were used to! And until my oldest hit about four or five, and then she started finding out about mac and cheese and looking at what was in everybody else’s lunch, and then it all started going downhill from there. But I’ve gotten her back by talking about those good bacteria and what she needs to feed them so they can be healthy and happy.
And it’s the same thing for us. I mean, the director of our Institute, Claire Fraser, who sequenced the very first bacterial genome ever, she was funny… Hearing her talk one day, she was saying, y’know, “Unlike anybody else, I see cake in the fridge and I see a salad, I want the cake. I don’t want that salad, but I know I need to eat that salad so that I’ll feel better.”
Y’know, and there is a big connection between… there’s the gut-brain axis. We’re starting to learn a lot about where it seems like our bacteria are actually producing some of the compounds that help with our mood regulation and things like that. So again, it’s back to that, good ol’, y’know, reduce your sugar and eat lots of fruits and vegetables, and those are the prebiotics.
Now for probiotics, I’m still kind of a little humbug-ish, I guess, about most probiotics. I think that the average person who actually is in good health— good health, meaning you don’t have any digestive system disorders, y’know, you don’t have Irritable Bowel Syndrome, […] syndrome or Crohn’s disease or any of those things…
And also, y’know, it seems like depression/anxiety are part of that balance as well. So you can kind of switch your microbiome a little bit by changing what you’re feeding for those organisms as well. Eating more fish oils and healthy oils and things like that. But, I… y’know, in my mind, as an ecologist, it is my fundamental training, what you have already picked up when you were a small child and then throughout your life is really what’s going to be there.
They’re there, the critters that have already moved in. So, sometimes I think of this as an apartment building or a dorm. So, when you’re filling up your apartment building or dorm, you want good residents, you want somebody who’s going to pay their bills.They’re going to keep the place clean. They’re going to, y’know, go to sleep and not… or at least not have loud parties. And so that’s, y’know, feeding your microbiome properly, using fruits and vegetables and healthy oils can promote those good, good folks coming in. But y’know, once the rooms are occupied, you can’t put any more people in there.
If it’s only one person per room, it’s one person per room. So those spaces are filled and you can’t even if there is a disruptive person who wants to come in and be in that dorm or in that apartment building, there’s no space for them. So they can’t live there. But if you start having people move out, your good neighbors moving out for whatever reason, then your disruptive neighbors can come in.
So probiotics in my mind are kind of more like more like the disruptive neighbors— they come in and they might be good, they might be bad or helpful or not helpful, but they’re not gonna live there with you unless there’s a space for them to live. Now, that being said, they can still come by and stand outside your window and make a lot of noise and be a pain in the butt, or they can plant flowers outside of your window and, y’know, make the landscape beautiful. So they can still do things that would influence your interaction and your wellbeing, but they’re not going to take up permanent residence there. So that’s the way I see probiotics. y’know, there are some that if you’re having real digestive system problems, then you can take antibiotics and try to get rebalanced to using them. But there’s not that many that have really gone through clinical trials and I think are substantive.
Adriana: Hm. So y’know how during pregnancy, and we’ve been told to “Avoid this,” “Don’t eat that,” y’know, “Don’t have the raw egg.” And that those recommendations, from what you said, are those enough to kick out the neighbors and create more space? Or is it something that I can… it’s not really going to affect your microbiome in the long-term or during the pregnancy?
Anne: Awesome. Yeah. So actually that’s where it’s a little bit different with pregnant women, right? Because our immune systems are a little bit more sensitive compared to that of most people, so that we’re not rejecting our fetus, right? So, in that case, y’know, you are still susceptible to things like salmonella and listeria and some of those bad guys… they can still get in because you have so many different versions of your immune system.
There’s… the microbiome plays an important… just the barriers that are present, whether it’s the mucus layer of your gut or whether it’s the skin layer, if you’re talking about the outside of your body. Then you also have your backup immune system, which is your innate immune system where your body is actually attacking things like the white blood cells and things like that.
So, yeah, I would not solely rely on my microbial partners to do it all. Again, I think, we’re these organisms that are really a collection of both microbes and human. So we need both parts of those, especially when you’re pregnant, when your immune system is… your human part of your immune system is ratcheted down a little bit.
So yeah, I would still avoid deli meats for listeriosis. That is a nasty, nasty bacteria. And, y’know, wash things carefully and be careful of salmonella and unbaked meats and things like that.
Adriana: Okay. Big concern for moms during pregnancy and birth is the status of their Group B Strep.
Anne: Oh, yes.
Adriana: And that is something that’s definitely microbial, right? So is there a “microbiological”— I don’t know if that’s a word— but a microbiological way to discourage the presence of GBS during pregnancy, and so hopefully have a negative GBS test outcome because you don’t have a prevalence of GBS and don’t have to have antibiotics during birth, which can then affect your baby’s microbiome as they come through in that seeding moment?
So walking it back, can we do anything?
Anne: Yeah. I think that’s a great question. I remember being so worried about that Group B Strep test in both… with both of my pregnancies and even with my first one where, y’know, she’s eight now, and we didn’t know so much of what we know now then, it was just my natural kind of fear of antibiotics— unnecessary antibiotics, I should say.
Because we certainly take antibiotics when we need them. But, anyway. Yeah, so Group B Strep is really interesting. It’s another one that is interesting bacteria in that, for the majority of people who have it, it’s not a problem. And in fact, it’s… I think it’s only like 1% of babies who are born who are colonized by Group B Strep actually ended up having some sort of complication due to that.
And it may even be less than that. I should have double checked on that number, but it’s really not as much as we worry about it. The ramifications of Group B Strep, which are really frightening things, actually don’t happen that often. The problem is when they happen, it happens quickly. And it’s one of those things that, y’know, as a mom, you’re always told if the baby’s temperature gets over 100.4, y’know, it’s an emergency. And that’s why, because one of the things could be strep potentially causes meningitis.
So, in that case, y’know, you really want to catch it, catch it quick, deal with it. And so it can be kind of easy in those early infant weeks that are so crazy, to potentially miss that and then have serious complications. So that’s why we worry so much about Group B Strep.
So that being said, a lot of people are carriers. How can you deal with it? So in some of these new vaginal microbiome studies that I was looking at, it’s interesting, because they really have found that women across the… they did longitudinal sampling of women across time, so they took non-pregnant and pregnant women and followed them and took samples, y’know, every so many weeks. I don’t remember how many weeks, but they surveyed them from first to third trimester, all the way through birth, actually. And they looked to see if their bacterial communities in the vagina, because that is where a Group B Strep lives, if the bacterial communities change over pregnancy.
And what they saw was that it really didn’t change so much. There were a few times when it changed, but in pregnant women, overall the community stayed pretty similar. So women who are dominated by lactobacillus, like Lactobacillus iners, they keep that throughout their pregnancy. Non-pregnant women, their microbiome, vaginal microbiome communities fluctuate a lot more than that.
And that’s probably… oh, that seems to be correlated with hormonal changes throughout the month. So that’s kind of interesting and helpful that it’s stable and suggests that you’re not going to drastically change from one state to another. However, Group B Strep can come in and invade, and that can cause potential problems even in the last few days. So, y’know, the thing is like, there’s not… we’re still at the infancy with so much of this, I mean, these studies.
Even look at this, the first study doing this longitudinal sampling to see if we even have similar microbiomes in the vagina, one place that has relatively few number of bacteria, y’know, that study wasn’t even done until 2014. And they didn’t… they were looking more for BV than they were— bacterial vaginosis— than they were worried about Group B Strep.
So the answer is, I don’t really know. There are… I know there are some probiotics under clinical trial now. People are looking into… to see if they can give lactobacillus suppositories— effectively, vaginal suppositories— and keep the balance more towards lactobacillus and keep those bad neighbors of Group B Strep from coming out and ever growing.
But, we’re just not there. So, y’know, again, the best recommendation I think is just to keep eating healthy fruits and vegetables and, y’know, have your yogurt. Make sure it’s— y’know, yogurt has active cultures, and drink the kefir— but you, the one thing you do need to worry about with fermented foods, or at least my experience with fermented foods is… And I need, this is something else I need to dig in the literature more about— I went to a fermented foods workshop, and I got so excited that I went from my regular, y’know, one cup of Greek yogurt a day, to added kefir and sauerkraut and kimchi, I think it was like every day. I went from this small fermented food product to a whole lot, and my eczema went absolutely crazy.
So I looked in the literature and found that actually, some of these lactobacillus actually do secrete histamines. And you think of antihistamines, right, that’s what you take when you have allergies and flare ups like that. So these are producing histamine and actually caused the flare ups.
So, y’know, don’t get crazy. Don’t do the typical American thing and say, “Oh, just a little bit is great, so the whole lot might be even better,” but moderation. Moderation is awesome.
Adriana: Don’t be ordering a scoby online and starting to do your own kombucha.
Anne: Yeah, totally.
Adriana: Like I did. I did. I did.
Anne: And if it’s just…
Adriana: It’s fun, but a lot of work!
Anne: Yeah, I haven’t done that yet. I mostly stick to yogurt so far.
Adriana: So how can we get these people on this GBS thing? Because that’s one thing that I find, like you said, the actual risk of it happening, of the complications, is so minimal, but if it happens, it’s extremely bad. And then because of that situation, we screen all pregnant people And if they show to be positive, then they get de facto antibiotics during birth, which…
Adriana: Right. Right. Well, do you… so depending on what they’re given, but usually you want two doses and I’d like… each place is different, but usually it’s like two doses with four hour separation and that’s the ideal amount of dosing so that when the baby is born, that’ll take the care of the GBS as that baby’s passing through that vaginal canal.
And you took away the GBS. And what else did you do? Y’know, all these other things that you took away just at that moment, you timed it perfectly. That’s doing harm.
Anne: Yeah, it is. And there’s a lot of people working on it. I just think we’re not there yet.
Adriana: Yeah. I… so I personally… that’s one of my pet peeves, not pet peeves, but that’s one of the things that’s close to my heart because I had… I was GBS positive and had antibiotics with my daughter and aside from the health effects of having antibiotics right then and, y’know, depleting the microbiome, it was annoying and it was like this… added intervention that now I had to figure that there was this thing going in my arm that was hurting, it hurts, and then we got to repeat it every four hours! So there’s a lot of reasons why it would be great to have an alternative to the antibiotics.
Anne: Yeah. I totally agree. And there is, I’m sure, y’know, there’s a vaccine that people are working on as well, but, yeah. Time, research, dollars, y’know. I think we’ll get there, ’cause it is something that a lot of people are very worried about.
Adriana: So one of the common anecdotal things that we’re always hearing out there is using garlic cloves vaginally to kind of offset GBS or even yogurt, any research on that?
Anne: Not that I know of. The idea of garlic cloves just scares the bejesus out of me, to borrow a term from my grandma, because, y’know, garlic is a really, really, really, really antimicrobial substance, so you’re going to be knocking out all sorts of stuff. And additionally, like, yeah, I just… I’m not big on disturbing ecosystems, whether it’s with something that comes from the ground or it comes from, y’know, a pill bottle.
So, as for yogurt, y’know, again, it’s hard to know there’s more of a chance that you might introduce something that you don’t want to introduce accidentally. Yeah, this is one of the few times where I’d be more likely to say, if you want to do anything, sure, a lactobacillus probiotic of any of the vaginal… vaginal “lacto”s won’t hurt you. Y’know, it might do some good. How it’s going to get from your gut to your vagina, I don’t know. No one knows that!
But again, I’m actually pretty optimistic about these clinical trials with the lactobacillus, that LACTIN-V— I think that, or a five, I’m assuming it’s a five and not a V— but I think that that has a really good chance of being something that could change the ratio.
Adriana: We’ll keep an eye on it. And if you have a link to it, I will add it to show notes so that listeners can keep an eye on it themselves too.
Anne: Yeah, totally. I’ll send you that link for the show notes.
Adriana: Fantastic. Thank you. Now, that other study that you were mentioning, on the vaginal microbiome… and I just realized, like, at the beginning of the show, I don’t know for what reason I turned Australian-slash-British and was saying va-GI-nal microbiome instead of VA-gi-nal, I heard myself and I was like, wait, that doesn’t quite… that sounds weird.
But anyway that the… you have a link to it on your site and I’ll add it to the show notes too, so that people can go take a look at it. I was skimming that article—
Anne: The ethnicity one? Is that the one you’re talking about? Is it the one about vaginal microbiomes and ethnicity? Is that the one you’re talking about?
Adriana: Yes. So it was the part about ethnicity that was really interesting to me, particularly because I am Latina/Hispanic, like, I am Venezuelan, so yeah. So that threw a whole different layer of complexity into the situation. Can you explain a little bit the ethnicity part of what this study found?
Anne: Yeah, that is such a fabulous study. It’s actually one of the researchers at the Institute where I’m a postdoc. And so one of the things that Jacques realized is that so many of the studies— and, y’know, we’ve seen this throughout time, right?— it wasn’t until, what, it was in the 1990s that women really started getting studied for medical clinical trials?
It was always done on men, white men, and people would say, “Oh, it’ll be the same way in women,” much less ethnic diversity of women. But, so similar with the microbiome work, y’know, we were focused mostly on white people, but being here in Baltimore and working directly with the medical school a lot, Jacques wanted to look more at the African American community here and also expand it to Asians and Hispanics.
So in their study— mostly refers to African-Americans, but there are other studies and some of these ongoing studies are actually with African women as well— what was really amazing is that they see that you can have different community state types of bacteria, so you can have… it’s kind of like I have a bowl/a tray of fruit out on our dining room table, and sometimes that tray of fruit has apples and pears and cherries in it, but sometimes it just has apples and pears.
Okay? So those are different community states. So one where it’s more diverse than the other, where it’s not as diverse. So those are different community states. And so what he was finding is there are all these different community states of bacteria that can exist in the vaginal microbiome of different women, but that you find some of these microbiome community types are more dominant in Black and Hispanic women than in white or Asian women. And what was interesting about that is that the dominant community state type there is one that’s not dominated by lactobacillus. So forever the medical field has thought that y’know, a lactobacillus vagina is a very healthy vagina.
And anything that doesn’t have lactobacillus is unhealthy. It has bacterial vaginosis. Well, what this study really demonstrated, and they’ve continued to work on this ethnicity angle because it’s so interesting and important. It’s really important to start, yeah, to diversify all of our work, in so many different ways.
But it was really surprising to see that the majority of African American and Hispanic women had this non-lactobacillus state. And so they would be deemed as having bacterial vaginosis by a doctor. However, they didn’t have any of the signs and they seemed perfectly healthy in every other way.
So it really seems like there’s this ethnicity component. And again, that can get back to this whole idea of, we’re not just a microbiome— a microbiome incubator, as much as I kinda like to think of humans as a microbiome incubator— y’know, we do have a human part, too. And so that’s where we can have these interactions between our human genetic self and our bacterial genetic self.
And that’s really why, maybe we’re starting to see where sometimes there’s a fuzzy answer, with either microbiome or human research, maybe it’s because we haven’t accounted for ethnicity or maybe we haven’t accounted for, y’know, some particular human gene that’s influencing our microbiome.
So it’s cool. But it’s also important to say, y’know, just because it’s not like what we were expecting, does not mean it’s sick. This is not a sick microbiome. This is not an ill microbiome. This is a net, a natural microbiome state for these women.
Adriana: Right. No, and it’s… that’s so important to underline, absolutely. And then bring it back to that GBS thing, I keep going back to it, but, y’know, that probiotic, that’s being researched, I think he called it Lacto, Lacto V? Five?
Anne: It’s called Lactin-V.
Adriana: Lactin-V, that’s, I’m guessing by the name, very much anchored on lactobacillus…
Adriana: And so what, if anything, is that going to do to African-American and Hispanic ethnicities, and will it be deemed effective or not, like, so much, right? Right.
Anne: Exactly. Those are the questions we need to be answering nowadays. I mean, and we need to be aware of the impact of ethnicity and diversity on these different studies that we’re doing. It’s just like, y’know, we can’t do just mouse studies and say they’re going to apply to humans. Well, even within humans, y’know, it’s still… the genes are the same, but there’s still some differences there.
And those differences seem to be really important when you’re dealing with microbial interactions, so I think that’s really important. And I don’t know… that’s one thing that we really don’t know is if, because you do have some women that have that non-lactobacillus dominant, community state, are other ethnicities as well. It’s just kind of how it averages out is that most… it’s more prevalent in Black and Hispanic women. So again, y’know, each person needs to know their own healthy baseline. But again, we just, we don’t know how that would… if that makes a difference. Yeah, there’s so much, so much fun stuff to figure out.
Adriana: We will wait optimistically!
Adriana: Yes. On a different note, Anne, what about cravings during pregnancy? Y’know, so far they’ve been thought to be hormone-driven, is this something that should be reconsidered in light of the increased understanding of the microbiome? Could it be our microbes that are, y’know, having us craving pickles instead of our hormones?
Anne: Oh, totally. Yeah. There’s… there’ve been several different studies, kind of, indicating that depending on your… which microbes in your gut seem to influence what you’re craving more or less. And so yeah, I could totally see that being, easily. Well, actually, I guess it’s kind of hard to disentangle hormones and bacteria in my mind, because again, with my insect work, people don’t think of insects as similar to humans, and there are many differences, but y’know, when it comes to host-microbe interactions, sometimes in these other systems, it can be a little bit easier to see some of these interactions coming out. And one of the things I saw in one of my insect’s systems was that the hormones that… well, as the insect went through metamorphosis, as it went from being, y’know, a wormy little maggot to being a beautiful fly, y’know, there’s this huge hormonal shift. And there was a huge shift in how the microbes were. So I really… it makes me really wonder if there isn’t this interaction between hormones and microbes, that really there’s this crosstalk. Hormones would be an excellent way for bacteria to eavesdrop on what’s going on in the host or coordinate with their hosts, y’know, however you want to think about it. So. Yeah, sure: cravings could easily be determined by the microbiome, or influenced by the microbiome, or hormones, or both.
Adriana: Well, and it makes sense because of… y’know, during the beginning of pregnancy, the hormones are changing drastically and all over the place. So, and then you get those crazy cravings or unusual-for-you cravings.
Anne: Yeah, one was ice cream with the first kid, and spinach with the second one. So, y’know, hey.
Adriana: Nice. Mine was grapefruit!
Anne: Oh, wow.
Adriana: I just wanted grapefruit, yeah.
Anne: Oh, that’s so interesting.
Adriana: It was intensely grapefruit.
Anne: That’s awesome.
Adriana: Yay! Who knows what my microbiome was doing?
Anne: Yeah, exactly.
Adriana: Anne, thank you so, so much for this talk. It’s been lots of fun.
That was assistant professor, researcher, and mother of two, Dr. Anne Estes. Anne is also the human host of the blog Mostly Microbes, which has a section filled with educational modules to help you teach your kids about microbes and the microbiome, that includes a bunch of kid book reviews. You can find Anne on Instagram @mostlymicrobeshost
And you can connect with us @birthfulpodcast on Instagram.
So, are you worried about pooping during birth? Did this episode help with that? We want to know! Why don’t you take a screenshot of this episode on your phone as long as you are not driving, right now, and post it to Instagram with your thoughts. Make sure to tag @BirthfulPodcast so we can see it and amplify it.
You can find the in-depth show notes and transcript of this episode at Birthful.com, where you can also learn more about my birth and postpartum preparation classes and download your free postpartum preparation plan.
Birthful is created and produced by me, Adriana Lozada, with production assistance from Aysia Platte.
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Come back for more ways to inform your intuition.
Lozada, Adriana, host. “What Does Your Poop Have to Do With Your Baby’s Microbiome?” Birthful, Birthful. June 29, 2022. Birthful.com.
About Anne Estes
Anne M. Estes, PhD is the human host of the microbiome blog, Mostly Microbes. As a microbiome scientist and mom, she is passionate about distilling the rapidly developing microbiome literature for parents, childbirth educators, and medical professionals so they can make informed medical and lifestyle decisions. Anne has two girls who inspire her to come up with creative ways to teach everyone about the amazing world of microbes. She has also been a contributing blogger to the Lamaze International blog, Connecting the Dots, and MicroBE.net, an academic blog about the microbiome of built environments. She is an Assistant Professor at Towson University, where she studies the microbes living in dung beetles and is overly excited to teach General Microbiology.
You can find Anne at www.mostlymicrobes.com
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