Microbiome Research and Women’s Health | Jennifer Fettweis | TEDxRVAWomen

Translator: David Hsu
Reviewer: Rhonda Jacobs So we are not 100% human, and that’s a good thing. Living in and on our bodies
are trillions of microorganisms or microbes for short – (Laughter) these include bacteria, viruses, yeast. And these microscopic
organisms collaborate; they form ecosystems that are very much
a part of who we are. Until recently, the functions of these
communities were largely unexplored, but we’re learning
that they are critical for our health and for our well-being. You see, traditionally, the study
of microbes had been focused on the role of pathogens, those bad actors that can cause
disease by acting alone. About a decade ago now, I joined a consortium of research
scientists across the United States in an effort to take the first census
of microorganisms that live in and on the different
parts of our bodies. The National Institutes of Health
sponsored this Human Microbiome Project, and that jump-started
this field of research. The time was right for this program. Dramatic reduction in cost
in DNA sequencing made it possible for us to study the genes
of the microbes that live in and on us. And I’ll just get technical
for a minute here: the microbes, their genes
and their other products, together, that’s the human microbiome. So when we set out on this new research, some of us thought that there might be
a core group of microorganisms shared between all people. We were wrong. But we did learn that each person
has a unique microbiome, and there’s not just one way
to be healthy. However, there are commonalities
among the microbial communities at the different body sites: so the mouth, the gut, the skin,
and in women, the vagina. That is particularly true when we look
at what the microbes are doing, when we look at their functions. And so, the microbial communities
that live in my mouth are more similar to the microbial
communities that live in your mouths than to those that live
on my forearm, for example. So, microbiome science is relatively new. It will take us many more years
to fully understand the role of these microbial communities. And while we know that there’s
not just one way to be healthy, it’s now clear that imbalances
in microbial communities are associated with a number
of different diseases, disorders, and other adverse health outcomes. So, for example, an imbalance
in the gut microbiome, that’s associated with
inflammatory bowel disease; an imbalance in the vaginal microbiome is a risk factor for
complications in pregnancy; and an altered microbiome is also linked with obesity and other
immune-related diseases. So we’re learning how
these organisms impact our health. In essence, the microbial
communities that live on us constitute an overlooked organ. One that we hadn’t previously
realized existed or acknowledged, but one that is critical
for many aspects of our health. So this begs the question: Can we cultivate a microbiome for health? And I think the answer is yes although we are just beginning
to understand how we might do so. So, one way we might do that is realize that our lifestyle impacts
our microbes too. There are several studies
that have shown that a change in diet has a dramatic impact on the microbial
communities that live in our gut. Antibiotic treatment can also
impact the microbiome. So as a society we must address
indiscriminate use of antibiotics. Antibiotics can be good. They can save lives, [treating illnesses]
caused by bacteria that cause infections; however, their mechanisms are not precise, and they can also kill
the beneficial organisms, and strip the normal flora. So it’s something we need to be careful of
and use these only when needed. In some extreme examples,
antibiotic use can lead to proliferation of an organism called
Clostridium difficile in the gut. Now, that’s a serious
intestinal infection. And when standard treatment fails,
it’s actually been demonstrated that a fecal microbiota
transplant can be effective. So, that is what you think it is. This is not your standard
organ transplant. (Laughter) I won’t go into the details
of how this is conducted, but stool from a healthy
donor is collected, and that’s used to repopulate
the gut of the patient. Bacterial species that have been
suppressed or killed off are replaced, and gut function is restored. And so while these examples
are very exciting – and I think that one demonstration here
with the fecal microbiome transplant is one of those examples – I think we must also exercise caution and not begin to modulate
our microbial communities before we fully understand
their functions and the potential risks of doing so. So, we’ve established
that the microbiome is part of us, and that we may even have
some degree of control over it, and I think that offers
a very new perspective on the age-old question
of nature vs. nurture: the relative importance
of our genetic makeup or innate qualities compared to our experiences
in shaping who we are as individuals. If we are able to cultivate
a microbiome for health, we may actually, in fact,
be able to change our very nature. So where does it all start? Where do we get our microbes? Comparisons of the human microbiome
with that of other primates suggest that our microbiome
has coevolved with us. We’re still learning how our microbial communities
and the genes and the functions are passed from one generation
down to the next, and how we maintain our human
microbial gene pool. One of my research directions as part
of the Vaginal Microbiome Consortium at Virginia Commonwealth University is focused on that question, beginning with understanding
the role of the microbiome in reproductive health and in pregnancy. So, we used to think that infants were
completely sterile when they were born; now there’s some debate
within the scientific community about whether infants may be exposed
to the microbiome in utero as part of normal development. However, what is clear
is that some infants are exposed to microbial infection,
and that can have adverse consequences. So in some of these cases, the infection
is spread through the bloodstream, and it crosses over the placental barrier. So some of you may have heard that pregnant women are often advised
not to eat soft cheeses, yeah? That’s to prevent risk of listeriosis, which is caused by a bacterium
that can lead to loss of pregnancy. Pregnant woman who contract
the Zika virus, whether that’s through an infected
mosquito or through a sexual partner, can pass that virus on to their fetus, and that can have devastating
consequences on development as we’re seeing an increasing number
of infants born with microcephaly, a birth defect where a baby’s head
is smaller than expected. However, the most common route
of infection, of intrauterine infection, is ascending infection from organisms
that originate in the vagina. So, in studies based here
in Richmond, Virginia, more than 5,000 women
have contributed samples and data to our ongoing microbiome projects. That has made it possible for us
to generate the largest data sets on the vaginal microbiome in the world. Through these studies, we’ve learned
that the vaginal microbiome of pregnant women is different
from that of non-pregnant women; and other groups have seen this as well. Specifically, pregnant women tend to have
vaginal flora dominated by Lactobacilli. So, these Lactobacilli are related
to organisms that are found in yogurt. And we think that their role
now is to keep out other potentially pathogenic organisms
from ascending and infecting the uterus, which can contribute to preterm birth. One in ten infants in the United States
is born preterm. And while many
premature babies do just fine, preterm birth is still
the leading cause of infant death. So one of the things
that you may find surprising is that many of these vaginal organisms
haven’t been characterized at all. So one of the things
that we’re doing in my lab downtown is studying the genomes of these organisms
to better understand their functions. We have established that the vaginal
microbiome is important for preventing ascending infection and for promoting healthy pregnancy. At birth, the vaginal microbiome
also seems to play a very important role in seeding the microbiome of the infant. There are several studies now
that have demonstrated that C-section babies compared
to vaginally-born babies have different microbiome composition,
at least in the early months of life. Similarly, there have been studies
that have looked at mode of feeding. And so breast milk contains microbes and prebiotics, which act
as food for microbes. And so breastfeeding can actually help
to shape an infant’s gut microbiome. Antibiotics, particularly repeated
courses of antibiotics, can impair the microbiome
establishment in early life. And, we’re still learning exactly
what this means; that’s not something
that’s completely clear. However, there have been
some recent studies that suggest that an impairment in early
microbiome establishment may be linked with some risks
for diseases later in life, such as obesity or asthma. More studies are definitely
needed in this field to better understand
what these long-term risks may be. So, we know that moms matter, and transmission of the microbiome
from mother to child at birth is something that’s very important for keeping our microbial
gene pool, if you will. However, I’ve only told you
part of the story. Microbes are also passed between people, and these aren’t just the ones
that cause disease. Children acquire microbes
playing with other children. People who live in a household,
they share microbes. There is even a study suggesting
we may share some microbes with our pets. I think that these interactions
may have a very important role for us maintaining our human
microbial gene pool. And once we recognize
that our microbes are part of us, I think we’ll realize that we’re more interconnected
than we ever would have imagined. (Applause)

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