The path to a person’s health may lie through their stomach, to paraphrase an old saying. Or at least it may reside in the multitude of microorganisms that inhabit the gut, an ecosystem known as the gut microbiome, according to researchers at UMass Chan Medical School.
Beth A. McCormick, PhD, the Worcester Foundation Chair II for Biomedical Research, chair and professor of microbiology and physiological systems, and director of the Microbiome Research Center and the Program in Microbiome Dynamics, studies the connection between the gut microbiome and diseases such as Alzheimer’s and inflammatory bowel diseases, as well as the immune system. She explained what we know about the gut microbiome and how scientists are investigating the mechanisms by which it affects our health.
What is the gut microbiome?
“There are microbes that colonize the gut, and the communities they live in are the microbiota,” Dr. McCormick said. “What they do in terms of their metabolic functions, their genetic production, how they protect us and how they have physiological and structural functions, is what we call the microbiome.”
The way we live plays a role in how microbes live in our gut, McCormick explained. Babies are basically germ-free until they are born. Even the form of birth – whether vaginally or by cesarean section – and whether babies are breastfed or bottle-fed will leave different signatures on the microbiota. People become fully colonized with their microbiomes at around 2 years of age, and as they age, the composition of microorganisms also changes. Even the composition of microorganisms among us is different.
Microbiome Research at UMass Chan
Faculty at the UMass Chan Microbiome Research Center take a holistic approach to studying the effects of this internal environment on health, integrating experimental, computational, and clinical approaches. Artificial intelligence is also employed for predictive modeling.
“The mission of the center is to really tackle the big challenges of what is our microbiome?” McCormick said. “We barely have a basic understanding of what their functions are during homeostasis, how microbes live in us through our current health. When you lose your balance, you enter a state called “dysbiosis”. So how does dysbiosis happen and how does it return to a healthy state?”
According to McCormick, being chronically in dysbiosis can lead to a range of health problems, including Crohn’s disease, autoimmune diseases and heart problems, and through a neurotransmitter connection known as the gut-brain axis, cognitive and neurodegenerative problems.
The gut-Alzheimer connection
UMass Chan researchers are in the midst of a large study supported by the National Institute on Aging to explore the causal mechanism of how the gut microbiome influences cognitive functioning among older adults living with Alzheimer’s disease.
Researchers are tracking cognitive functioning and gut microbiome characteristics among older adults with and without Alzheimer’s in a variety of settings over two to three years. Some patients’ cognitive function will decline rapidly during this time and others will progress more slowly.
“We hope that by longitudinally analyzing the timeline of these patients, we can bring together all of these previously unconnected factors in a way that we can determine the causal effect and, hopefully, learn from there how to intervene and restore health,” McCormick said.
The Alzheimer’s study’s principal investigator is John P. Haran, MD’07, PhD’18, professor of emergency medicine and microbiology and physiological systems and clinical director of the UMass Center for Microbiome Research.
Other researchers at UMass Chan are investigating how modulating the microbiome through food may influence Crohn’s disease; how microbial communities influence infectious diseases, including COVID-19; and using the gut microbiome to counteract the effects of radiation exposure, among other topics.
Can we change our gut microbiome?
McCormick said that while sales are huge for probiotic supplements, which contain live bacteria that are good for the gut, they may not alter our microbiome in the way we think.
“Remember, we have 100 trillion organisms existing in our gastrointestinal tract, and one of their important functions is to keep out invaders,” she said. “So when you take a probiotic supplement or eat yogurt with live bacteria or fermented foods, just by the natural function of gut physiology, the existing microbiota will try to expel that probiotic. So, you have to take these probiotics continuously on a daily basis to maintain the presence of these organisms in the gastrointestinal tract.”
McCormick said researchers are trying to identify new probiotics that already exist in the gut and harness them in ways that haven’t yet been discovered.
Science for Living stories feature perspectives from UMass Chan Medical School experts on the research behind health news headlines. If you have ideas about topics you would like to see explored, please contact susan.spencer1@umassmed.edu.
