by Nancy Clark, MS, RD, CSSD
It's In Your Gut!
When I think about eating, I think about the yummy taste of food and the pleasure of feeling satiated. But after attending a Harvard Medical School conference on Gut Health, Microbiota and Probiotics Throughout the Lifespan, I now realize I am not feeding my body but rather the 100 trillion bacteria that live in my gut – my microbiome. We have about 3 to 4.5 pounds of microbes that outnumber human cells by a factor of 10 to 1.
The microbiome is a signaling hub. Gut microbes produce neurotransmitters that talk to the brain. This ultimately impacts our immune system, brain, weight, and mood. Genetics, diet, and environment influence these microbes.
Gut microbes can be our best friends or our worst enemies. Thanks to antibiotics, we no longer suffer from infections and illnesses such as pneumonia. But, the antibiotics that kill the bad bacteria also kill the good guys. Animal studies suggest antibiotics can kill off 80% to 90% of the total microbiome. Does this have a lingering effect? For example, in humans, is the overuse of antibiotics related to the dramatic rise in autism, anxiety, diabetes, asthma, Crohn’s disease, MS, and yes, obesity? (The highest rates of obesity are seen in the states with the highest use of antibiotics.)
We have much to learn about the microbiome. Perhaps these conference highlights will encourage you to eat well to invest in having the healthiest possible gut. That, ultimately, will help you be the healthiest runner you can be.
What to do
Much more research is needed to determine if the results of microbiome studies with animals hold true for runners. We also need to learn about proper use of probiotic supplements. In the meanwhile, the probiotic industry is booming – and it is unregulated by the FDA. Hence, a note of caution: The quality of a probiotic is not guaranteed.
Your best bet is to feed your gut microbes (and your muscles) generous portions of fiber-rich carbohydrates from fruits, vegetables, legumes, beans and whole grains. You’ll naturally do this when you eat, for example, fewer cookies and instead snack on dried fruit. Yogurt, kefir, blue cheese and miso are also smart choices.
In the future, sports dietitians will be able to offer personalized nutrition based on each athlete’s microbiome. Until then, stay tuned, and know that a high-quality sports diet is the same diet that will support good gut health as well as top performance.
Nancy Clark, MS, RD counsels both casual and competitive athletes in the Boston-area (Newton; 617-795-1875). Her Sports Nutrition Guidebook and food guides for runners, marathoners, and cyclists are available at www.nancyclarkrd.com. See www.NutritionSportsExerciseCEUs.com for information about online and live workshops.