Our digestive health has a vast influence on our well-being, affecting our immune system, brain function, body weight, and more, says Avlin Imaeda, MD, PhD, associate professor of medicine (digestive diseases), an expert in metabolic health and weight loss. These impacts are just beginning to be understood, she says.
Below, Imaeda shares the latest research on three ways to improve gut health.
Eating whole foods, such as fruits and vegetables, helps to cultivate a healthy microbiome—the bacteria, fungi, and viruses that live in our gut, mostly our colon—which can help stave off disease. Ingesting foods that have been processed, either mechanically or chemically, can adversely impact insulin sensitivity and raise the risk of developing type 2 diabetes as well as lead to weight gain, according to Imaeda.
For example, Imaeda says, drinking a fruit smoothie instead of eating whole fruit can cause a spike in blood sugar because liquid is easier to digest. This spike, which requires the pancreas to produce more insulin, has reward effects like a drug on your brain, driving you to want more, Imaeda says. Finally, because liquid passes quickly, we get hungry again sooner despite the high calorie content of the smoothie, which likely contains more fruit than we would eat unprocessed, or whole.
Chemicals in food, such as preservatives and nonnutritive sweeteners, may have other difficult-to-predict negative impacts on health, Imaeda adds.
“Evidence suggests that exercise leads to a healthier, more diverse microbiome and increases butyrate, a short chain fatty acid that is produced by bacteria from fiber that is ingested in the diet but cannot be broken down without bacteria,” Imaeda said. “Butyrate is one of the key fuels that the cells lining the colon need to grow, divide, and stay healthy.”
In addition, Imaeda says, increased levels of butyrate appear to be beneficial for reducing inflammation, preventing and reducing severity of inflammatory bowel disease, reducing the risk of colon cancer, and overall immune health.
Studies show that sleep has a significant effect on psychiatric conditions, systemic inflammation, learning, fertility, weight, and other aspects of health, Imaeda says. “New research shows that some gut bacteria and the proteins they produce cycle based on circadian rhythms involving sleeping and eating behavior,” she said. “This can impact processes such as lipid metabolism and potentially, at least in mice, the ability to respond to infections.”