Adding key foods to a diet will help restore gut health

When it comes to gut health, putting the right foods into your diet might be as important as what you leave out, according to Dr. Chris Damman, a UW Medicine gastroenterologist.

“What you take out might be starving your gut microbiome,” said Damman, referring to the trillions of bacteria and fungi that live in one’s gut. “People focus on the nutrients their body needs when they eat, but they don’t focus so much on the nutrients their microbiome needs.”

Damman has studied the microbiome and its effects on health for 20 years.  His focus has been on microbiome's role as a protector against inflammatory bowel disease and metabolic disease as well as infectious diarrhea and malnutrition. At the Bill & Melinda Gates Foundation, he led an Initiative that developed several therapies to treat malnutrition. 

Most dietary advice focuses on lists of what to avoid: sugars, saturated fats, salts and processed foods. While this information is important, Damman said, “this approach can take one only so far to health.

"As we continue as a nation toward increasing obesity and diabetes, we have to realize that that many commercial and fad diets that avoid certain foods and nutrients only lead to more cravings that eventually overcome the diet and cause folks to gain weight back,” he said. “What we need to do is add back good foods and nutrients that feed a healthy microbiome that as it turns out help regulate appetite and metabolism.”

This can be done by consuming whole grains, beans, fruits, vegetables and nuts. The Mediterranean diet and others effectively improve health outcomes, but these diets can be hard to maintain in the long run, he said.

“If you revamp your microbiome by focusing on the nutrients they consume, they will produce metabolites like butyrate that stimulate the body to naturally produce factors like GLP-1, a blockbuster drug for diabetes and obesity, to help reset the metabolism so you’re not craving sugary foods as much,” he said.

There are more microbes (roughly 38 trillion) than human cells (30 trillion) in our bodies. Nutrients for the microbiome can be summarized as the “four F's” (one is phonetic): fibers, phenols, fermented foods, and healthy fats, Damman said. 

Microbiome-promoting fibers are particularly high in whole grains (e.g. oatmeal) and beans. Phenols give the colors of the rainbow to fruits and vegetables; think blueberries, red peppers and purple cabbage. Fermented foods include brined pickles, sauerkraut, kimchi and yogurt. Healthy fats include some vegetables and their oils like olives and avocados that are high in omega-3 fatty acids.

Focusing on adding the four F's to one's diet encourages good gut bacteria (e.g. Bifidobacterium and good Clostridium species that produce butyrate) to flourish. Studies have shown this can boost your metabolism, immune system, brain, and even life span, Damman noted. Good bacteria help produce anti-inflammatory agents like acetate and butyrate and other factors that decrease bad bacteria (e.g. some strains of E. coli and Klebsiella) associated with mood disorders, irritable bowel syndrome and chronic diseases caused by inflammation. Some studies have even shown links between good and bad microbes and the brain in depression and Alzheimer’s disease, he added.

The results of a microbiome-friendly diet might be fairly immediate. “Within the first week, you might see an improvement in bowel habits, less cravings for sweets, and your appetite may be more regulated,” he said. “Surprisingly, you might also sleep better.”

For details about UW Medicine, please visit http://uwmedicine.org/about.