A new study, published in November in Medicine & Science in Sports & Exercise, saw scientists from the University of Illinois at Urbana-Champaign tracking people’s guts contents and microbiome changes as response to an unfamiliar exercise routine. The paper’s headline reads “Exercise Alters Gut Microbiota Composition and Function in Lean and Obese Humans”. Results suggest that exercise may change the composition and activity of the trillions of microbes in our guts in ways that could improve our health and metabolisms in the long term!
Those portions of our bodies that seem uninvolved in workouts can have seemingly crucial effects on the whole metabolism dynamics, from digestion to mood and types of microorganisms coexisting with us as a unique ecosystem – the human body.
This microbiome includes countless different species of microbes in varying proportions that interact, compete and busily release various substances that are implicated in weight control, inflammation, immune responses and many other aspects of health throughout our bodies.
Now we know that our microbiomes can change as our lifestyles do and that has a direct effect on basically everything we do and everything that happens to us (injury recovery, disease, mood etc) Diet clearly affects the makeup of a person’s microbiome, as do illness, certain drugs, how much we weigh and other factors. But what about exercise?
Previous studies have shown that endurance athletes tend to have a somewhat different collection of microbes within their intestines than sedentary people do, especially if the athletes are lean and the sedentary people are not.
You can read in detail how it was set up, but basically their analysis showed that the volunteers’ gut bugs had changed throughout the experiment (which involved a period of exercise and complete absence of exercise), with some increasing in numbers and others declining. The researchers also found changes in the operations of many microbes’ genes. Some of those genes were working harder now, while others had grown silent.
The most discouraging finding for the possible replications of this study and reaching a broader conclusion was that most changes were not shared from one person to the next. Everyone’s gut responded uniquely to exercise!
But there were some similarities that they could use to formulate a baseline conclusion. In particular, they noted widespread increases in certain microbes that can help to produce substances called short-chain fatty acids. These fatty acids are believed to aid in reducing inflammation in the gut and the rest of the body.
Short-chain fatty acids also work to fight insulin resistance, a precursor to diabetes, and otherwise bolster our metabolisms.
Most of the volunteers had larger concentrations of these short-chain fatty acids in their intestines after exercise, along with the microbes that produce them.
These increases were greatest, though, among the volunteers who had begun the experiment lean compared to those who were obese, the scientists found.
And perhaps not surprisingly, almost all of the changes in people’s guts dissipated after six weeks of not exercising. Their microbiomes basically went back to the same state as before the study started.