Microbes need to eat too

There are approximately five pounds of bacteria in the average human’s gut,² and they need food. You are what you eat? So are your bacteria! Our diets play a huge role in shaping how diverse and well balanced our gut microbes are, or are not and scientists are discovering that our microbes thrive on some of the same nutrients that we do. Talk about mutually beneficial!

• Berberine. Berberine is a plant compound found in goldenseal and Oregon grape root and has been shown to improve metabolic disorders such as type-2 diabetes, metabolic syndrome, and obesity. One of the ways in which it is believed to work is through its beneficial effect on the gut microbiota. In research published earlier this year, berberine was found to significantly increase a type of beneficial bacteria called Akkermansia muciniphila that is involved in maintaining the thickness of the intestinal mucous lining, which acts as a barrier and prevents toxins from entering the blood stream via the gut lining (leaky gut).³ Other research found that berberine increases the abundance of bacteria that produce butyrate, a short-chain fatty acid that acts as a primary energy source for the cells that line the colon, which helps maintain a healthy mucosal lining. Butyrate is also required for these cells to help maintain oxygen balance in the gut, preventing dysbiosis (an overgrowth of pathogenic bacteria).⁴ Berberine has also been shown to increase populations of other beneficial bacteria, while inhibiting the growth of pathogenic bacteria.⁵
• Cranberry. Polyphenols have long been studied for their health-promoting properties, and now scientists are beginning to investigate their beneficial relationship with the gut microbiota; for example, research has shown that polyphenols require processing by gut bacteria to be transformed into their more health-promoting bioactive metabolites.⁶ Recent research has shown that the polyphenols in cranberry also increase the number of Akkermansia muciniphila, the bacteria that help maintain the mucosal lining of the gut. Additionally, animal research has shown that cranberry extract can prevent weight gain and improved insulin sensitivity in association with an increase in A. muciniphila.^{7 8} Complex carbohydrates found in cranberries called xyloglucans are used by some species of bacteria as a food source and have been shown to prevent E. coli from adhering to the epithelial lining of the colon as well.^{9 10}
• Curcumin. Curcumin, a polyphenol found in turmeric, has diverse pharmacological effects, yet it is known to have low systemic bioavailability. This has lead researchers to explore the hypothesis that curcumin exerts its health benefits through modulation of gut bacteria. Studies have found that curcumin supports a healthy balance of bacteria in the gut and like berberine, can increase the number of butyrate-producing bacteria. Animal studies suggest that curcumin may be a potential treatment for irritable bowel diseases (IBD) such as colitis via its “modulation of gut microbial structure.”^{11 12}
• Omega-3s. We know that the omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are potent anti-inflammatories and play important roles in cardiovascular health and brain health; it turns out they are also good for the gut (bacteria, that is). Research has found that EPA and DHA increase microbial diversity and help increase the production of short-chain fatty acids, an important energy source for bacteria. They can also reverse dysbiosis, bringing a healthy balance back to the gut microbiota, as well as influence the gut-brain axis.^{13 14}
• Micronutrients. Did you know that your gut bacteria can have nutritional deficiencies? It’s true! Just as we require vitamins A, C, and E, folic acid, iron, zinc, magnesium, and others to function, so do our bacteria. They use micronutrients as substrates and cofactors for a variety of physiological processes (just like us!) and nutritional deficiencies can affect the composition and function of the microbiota. Research has discovered that reducing micronutrient availability contributes to an overgrowth of pathogenic bacteria and disrupts the normal functioning of our good bacteria, “…indicating that these nutrients are essential for the development of healthy gut microbiota.”^{15 16} A quality multivitamin and mineral supplement will ensure you and your gut bacteria get the micronutrients you need to thrive.
• Fiber, resistant starch, and prebiotics. Bacteria love fiber! Unfortunately, most Americans don’t. The Standard American Diet is woefully low in fiber, and studies have found that those consuming a typical Western diet have less bacterial diversity compared to those eating a more fiber-rich diet (i.e., more veggies!). Fiber is fermented and metabolized by our gut bacteria into short-chain fatty acids (SCFA), which are key energy sources for the bacteria as well as the cells that line the colon. SCFAs also lower the pH in the colon, inhibiting the growth of pathogenic bacteria, and have antiinflammatory properties. Fiber and resistant starch (such as cooked and cooled rice and potatoes) are considered prebiotics—the non-digestible parts of foods that support the growth and activity of health-promoting bacteria.^{17 18} Note: If you are dealing with imbalances or gut issues such as irritable bowel disease (IBD), too much fiber (i.e., prebiotics) may be harmful. Take an individual approach; if you find fiber brings you discomfort, then cut back.

 
Whole body health is best supported in a multi-faceted, holistic way, and your gut microbiome is no different. Probiotics certainly hold an important place when it comes to cultivating and maintaining a healthy balance in your gut, but for a truly healthy, diverse, and well-balanced microbiome, consider a more comprehensive approach. And remember, what’s good for you is good for your gut (microbiota)!

References available upon request