THE GUT-BRAIN CONNECTION
Laura Mattson, DO
Physical Medicine and Rehabilitation Resident – University of Michigan
Based upon: Functional Nutrition for Pain—The Science of How the Gut and Mind Interact
Presented by Jessica Drummond, DCN, CNS, PT – The Integrative Women’s Health Institute
2019 IPPS Annual Meeting
How are the microbes in your gut and your brain connected?
What in the world are microbes doing in my gut?
o All of us have trillions of microorganisms (bacteria,
viruses, protozoa and fungi) that live, for the most part, in
harmony with us in our gastrointestinal tract (the long
tube that runs from our mouth to our anus). Most of
these microbes live inside our bodies but do not make us
sick. In fact, they play an important role in our health.
They help us to digest our food, protect us from harmful
bacteria that cause disease, produce vitamins, and
regulate our immune system. These microbes and their
DNA are collectively referred to as the gut microbiome. Image Credit: CC0 Public Domain
What is the connection between the microbiome and the brain?
o Our brain and gut are connected by a network of nerve cells and a highway of
chemicals and hormones. This connection is called the gut-brain axis. Information is
constantly shared between the brain and the gut about how hungry you are, your stress
level, whether you have ingested harmful bacteria, and much more. The microbes in
the gut can also release chemicals that have a role in inflammation and impact our
mood. In this way, the microbes in our gut, the local nervous system of the gut, and our
brain share a lot of information.
Do changes in the microbiome affect our health?
What can go wrong in this system?
o The microbes in our gut live in a fine balance. We need a mixture of good microbes to
carry out different functions. When this balance is disrupted, it is called dysbiosis.
Dysbiosis can have negative effects on our health. Some things that can lead to
dysbiosis are antibiotic use, consumption of alcohol and certain diseases.
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Do women with pelvic pain have changes in their gut microbiomes? Can these changes
influence pain?
o Women with pelvic pain have different types and numbers of microbes that inhabit their
digestive tracts than healthy adults. Studies have evaluated women with vulvodynia
and endometriosis. Low levels of some of the more beneficial bacteria and high levels
of some of the more harmful bacteria have been observed. This tells us that there may
be a relationship between painful conditions and the gut microbiome, but further
research is needed to tell us if these changes cause pain. Right now, there is a small
group of studies in animals suggesting that changes in the microbiome may lead to
changes in the sensation of visceral pain (pain related to an organ, such as the uterus
and the bladder).
What can I do to optimize my nutrition and promote a healthy gut?
What is the best diet for my health and microbiome?
o There is no one diet that is perfect for everyone and there are many healthful ways of
eating across cultures and food preferences. There are, however, a few important
principles to keep in mind.
o Emphasize plants. This helps feed the good bacteria
in our gut. This means eating 8-10 servings of
vegetables per day.
o Consume foods with fiber. Foods with fiber help
the good bacteria to multiply in our gut. Some
examples of these foods are asparagus, bananas,
garlic, onions, and whole grains.
o Minimize added sugars. Examples of foods with
added sugar are sodas, desserts, and even ketchup.
It is important to read food labels. Consuming
large amounts of sugar or artificial sweetener can
lead to gut dysbiosis. Image Credit: American Heart Association
o Eat the rainbow. Plants derive their colors from
phytochemicals found within them. The color of a fruit or vegetable can help tell you
what types of nutrients it contains. Eating foods of different colors allows you to easily
access all the vitamins and minerals you need.
What are other ways to promote a healthy microbiome and good digestion?
o Regular physical exercise can assist with gut motility (the efficiency with which your
food moves through your body), prevent constipation, promote a healthy weight, and
decrease stress. The Physical Activity Guidelines for Americans suggest at least 150
minutes of moderate intensity activity and 2 sessions of strength training per week.
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o Stress can cause changes in the makeup of your gut microbiome. Lowering your stress
through exercise and mindfulness meditation may help restore the health of your
microbiome and promote your overall well-being.
Additional References:
Carabotti, Marilia, et al. “The Gut-Brain Axis: Interactions between Enteric Microbiota, Central and
Enteric Nervous Systems.” Annals of Gastroenterology, Hellenic Society of Gastroenterology,
2015, www.ncbi.nlm.nih.gov/pmc/articles/PMC4367209/.
Carding, Simon, et al. “Dysbiosis of the Gut Microbiota in Disease.” Microbial Ecology in Health and
Disease, Co-Action Publishing, 2 Feb. 2015, www.ncbi.nlm.nih.gov/pmc/articles/PMC4315779/.
Chichlowski, Maciej, and Colin Rudolph. “Visceral Pain and Gastrointestinal Microbiome.” Journal of
Neurogastroenterology and Motility, vol. 21, no. 2, 2015, pp. 172–181,
https://doi.org/10.5056/jnm15025.
Conlon, Michael A, and Anthony R Bird. “The Impact of Diet and Lifestyle on Gut Microbiota and
Human Health.” Nutrients, MDPI, 24 Dec. 2014,
www.ncbi.nlm.nih.gov/pmc/articles/PMC4303825/#B48-nutrients-07-00017.
Hair, Marilyn, and John Sharpe. Fast Facts About The Human Microbiome. The Center for
Ecogenetics and Environmental Health, University of Washington, 2014,
depts.washington.edu/ceeh/downloads/FF_Microbiome.pdf.
“Physical Activity Guidelines for Americans.” HHS.gov, US Department of Health and Human
Services, 1 Feb. 2019, www.hhs.gov/fitness/be-active/physical-activity-guidelines-for-
americans/index.html.
