We all know that exercise is good for us, while a high-fat diet may not be so good.
A recent study, led by Michigan State University researcher Laura McCabe, supports findings that a high-fat diet can negatively affect the bacterial composition of your intestine and decrease bone density, while exercise can counteract these harmful changes.
The research is published in the journal Bone and has also appeared in Nature Reviews.
With the current epidemic of obesity in the United States, the impact of an unhealthy weight and high-fat diets on bone health is an area of significant concern. Previous MSU studies have indicated a link between intestinal balance and bone health.
“We’ve been examining the role of the intestinal microbiome in regulating bone density, and we know that exercise benefits bone health by actively stimulating bone cells to form more bone” said McCabe, a physiology professor in the College of Osteopathic Medicine. “Our study suggests that exercise can actually change the microorganisms in the gut, which could also contribute to exercise-induced benefits to the bones.”
Trillions of bacteria and hundreds of different bacterial species reside in your intestine, some good and some bad for your health. A high-fat diet can cause an overabundance of harmful bacteria in this area, known as intestinal dysbiosis.
During the study, male mice were fed either a low-fat diet, with about 10 percent of calories coming from fat, or a high-fat diet, with 60 percent of calories coming from fat, and kept under sedentary or voluntary exercise conditions for 14 weeks.
“Our results showed that the high-fat diet modifies the microbiota composition, and that the unhealthy bacteria may contribute to barrier breaks in the GI tract, causing mild inflammation in the body,” McCabe said. “But exercise helps maintain a healthier microbiota. The bottom line is that exercise may help you eat your high-fat diet without getting all of the negative effects.”
In addition to causing obesity, a high-fat diet can cause increased fat in the bone marrow. Instead of stem cells producing bone-making cells, they produce fat cells that get stuck in the marrow, which is often seen in osteoporosis. McCabe said that exercise also prevented this from occurring and caused blood glucose levels to decrease as well.
“Going forward, we would like to see if the immune system plays any role in linking exercise, microbiome, diet and bone health,” said Narayanan Parameswaran, professor in the Department of Physiology and co-author of the paper.
The researchers are now working to identify the mechanism that contributes to exercise-induced changes related to the intestine and bone health.
“This is an exciting area of bone physiology that emphasizes the importance of communication between different organs of the body,” McCabe said. “Not only is it cool that the gut microbiota can influence bone density, it suggests that in the future we may be treating people’s intestine to keep them healthy.”
