Fiber and fermented foods aid the gut microbiome, contributing to better health and mood.
An F may mean failure in school, but the letter earns high marks in your diet. The two biggest dietary Fs — fiber and fermented foods — are top priorities to help maintain healthy digestion, and they potentially offer much more. How can you fit these nutrients into meals? Can this help your overall health as well as gut health?
Fiber, fermented foods, and the gut microbiome
The gut microbiome is a composed of bacteria, viruses, fungi, and other microorganisms living in the colon (large intestine). What you eat, the air you breathe, where you live, and many other factors affect the makeup of the gut microbiome.
Some experts think of it as a hidden organ because it has a role in many important functions of the body — for example, helping the immune system function optimally, reducing chronic inflammation, keeping intestinal cells healthy, and providing some essential micronutrients that may not be included in a regular diet.
Your gut communicates with your brain through pathways in the gut-brain axis. Changes in the gut microbiome have been linked with mood and mental health disorders, such as depression and anxiety. However, it’s not yet clear that these changes directly cause these types of problems.
We do know that a healthy diet low in processed foods is key to a healthy gut microbiome. And increasing evidence suggests that fiber and fermented foods can play important parts here.
Which foods are high in fiber?
Fruits, vegetables, legumes, nuts, seeds, and whole grains are all high in fiber. The Dietary Guidelines for Americans has a comprehensive list of fiber-rich foods and their calorie counts.
What about over-the-counter fiber supplements that come in capsules, powders that you mix with water, and chewable tablets? “If you have trouble eating enough fiber-rich foods, then these occasionally can be used, and there is no evidence they are harmful,” says Rimm. “But they should not serve as your primary source of dietary fiber.”
Which fermented foods should you choose?
Fermented foods have a range of tastes and textures because of the particular bacteria they produce during fermentation or that are added to foods. Yogurt is one of the most popular fermented foods (look for the words “live and active cultures” on the label). Still, many options are available if you are not a yogurt fan or want to expand your fermented choices. Kimchi, sauerkraut, kombucha, and pickles are a few examples.
As with fiber, probiotics are also marketed as over-the-counter supplements. However, like all dietary supplements, they do not require FDA approval, so there is no guarantee that the types of bacteria listed on a label can provide the promised benefits — or are even in the bottle. “Therefore, it is best to get your probiotics from fermented foods,” says Eric Rimm, professor of epidemiology and nutrition at Harvard’s T.H. Chan School of Public Health.