Diabetes and the Microbiome

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Diabetes and the Microbiome

In the past, “diabetes” and “probiotics” were not words you would often hear in the same sentence. Recent studies of the role of probiotics in human health have found a stronger connection between them than previously thought. Probiotics are often referred to as good bacteria due to their importance to our overall health. We have learned that it’s important to eat foods that nourish and maintain these good bacteria as they can produce a multitude of health benefits.

“Much of our immune system resides in our gut, so it stands to reason that we want to keep our gut healthy to confer those benefits on our entire body,” says Kristina Campbell, author of The Well-Fed Microbiome Cookbook: Vital Microbiome Diet Recipes to Repair and Renew the Body and Brain (Rockridge Press).

What’s the difference? Understanding prebiotics and probiotics

Simply put, prebiotics are the food source for beneficial probiotics. Prebiotics are undigestible fibers that are necessary to cultivate a healthy gut. Without prebiotics, probiotics do not have the food they need to do their job effectively.

Probiotics are bacteria and yeasts that confer health benefits to the human body in multiple ways. Your intestines house over a thousand different types of bacteria, which are often referred to as your “microbiome” or your “intestinal flora.” Probiotics do everything from manufacturing certain vitamins like K and some Bs to performing certain metabolic functions to keeping your gut walls strong, which results in a stronger immune system.

The study of the different ways probiotic strains aide the human body is still in its infancy. As scientists continue to discover how important probiotics are to our overall health, you should plan to hear much more about how they work with the body to aid digestion, strengthen the immune system, influence weight, and impact mood.

Microbiome definitions

Prebiotic: A nondigestible dietary fiber that promotes the growth of beneficial bacteria (probiotics) in the digestive tract.

Probiotic: Bacteria and yeasts that confer health benefits to the human body.

Probiotics and diabetes: Growing evidence

Within the past few years, scientists have pieced a puzzle together that shows how important the gut microbiome is to overall health and the management of different diseases, including diabetes. One important byproduct of eating a high-fiber, low-sugar diet for managing diabetes is the production of short-chain fatty acids that nourish our gut-lining cells, reduce inflammation and help control appetite.

The importance of short-chain fatty acids in the health of people with diabetes was established by a study published in 2018 in the journal Science. Researchers determined that a deficiency in short-chain fatty acid production from reduced fermentation of dietary fibers in the gut is associated with type 2 diabetes.

A high-fiber diet evaluated in the study included whole grains and traditional Chinese medicinal foods rich in prebiotics, which promote growth of short-chain fatty acid-producing gut bacteria. After 12 weeks, patients on the high-fiber diet had greater reduction in A1C levels (a measure of long-term glucose control). Their fasting blood glucose levels also dropped faster, and they lost more weight.

“Our study lays the foundation and opens the possibility that fibers targeting this group of gut bacteria could eventually become a major part of a diet and treatment,” says Liping Zhao, PhD, professor in the Department of Biochemistry and Microbiology, School of Environmental and Biological Sciences at Rutgers University in New Brunswick, New Jersey, and the author of the study. “Hopefully in the future, the use of certain dietary fibers will be considered a standard approach to a multi-prong treatment of diabetes.”

The role of prebiotics in health

To understand how bacteria thrive, one must consider how prebiotics fit into the overall equation. In 2017, a new consensus definition of prebiotics was published by the International Scientific Association for Probiotics and Prebiotics, defining prebiotics as “a substrate that is selectively utilized by host microorganisms conferring a health benefit.” What this means is that certain foods containing prebiotic properties will influence the type of probiotics that live in your gut. For example, eating foods high in sugar will feed the bad bacteria, while eating a healthy mix of prebiotic foods will feed the good bacteria you are trying to maintain. Ultimately, foods you put in your body can influence what type of bacteria — both healthy and unhealthy — live in your gut.

“More research is needed to identify which prebiotic foods feed which beneficial bacteria, but eating a variety of fiber-rich foods is a good place to start,” adds Zhao.

We do know some foods that have the prebiotics necessary to increase short-chain fatty acid production. Some examples of the types of fiber you should eat to increase short-chain fatty acids in your body are fructooligosaccarides (FOS) found in Jerusalem artichoke, garlic, onions and asparagus; inulin found in sprouted wheat, garlic and leeks; and resistant starches found in rice, oats, barley and legumes.

Healthy gut cheatsheet

Prebiotics: Jerusalem artichoke, garlic, onions, leeks, asparagus, sprouted wheat, rice, oats, barley and legumes

Probiotics: Cultured dairy products like yogurt or kefir, tempeh, miso, sauerkraut, kombucha, pickles and kimchee 

Good bacteria

There are three main ways to populate your gut with bacteria: through your diet, through the environment around you, and by supplementing with a multi-strain probiotic. Fermented foods such as yogurt, kefir, tempeh, miso, sauerkraut, kombucha, pickles and kimchee are all delicious additions to your diet. “There are no current guidelines as to how much per day is therapeutic, but you can’t go wrong adding some fermented foods each day,” says Campbell.

Humans have traditionally picked up bacteria from their environment. As society has modernized, the use of microorganism-killing products has given us cleaner environments, but not necessarily always healthier ones. Chronic inflammatory diseases have sharply increased. The hygiene hypothesis, also known as the microbiome depletion theory, states that a lack of early and continuing exposure to microorganisms increases our susceptibility to diseases by suppressing the natural development of the immune system. 

The last way to add probiotics into your daily life is to take a multi-strain probiotic supplement. There are probiotic supplements with many health claims on the market, which can make choosing one seem overwhelming. The best-studied bacteria used in supplements are Lactobacillus and Bifidobacteria strains. Look for a supplement that contains a number of different strains, and that ideally includes B. longum, B. Bifidum, L. acidophilus, L. fermentum, and L. rhamnosus.

Sugarless diets

The good news is that the foods that provide a healthy microbiome are all low on the glycemic index and rich in fiber. According to Campbell, “What gut microbiome science helps us understand is that the things that should be avoided by the general public, and especially those with type 2 diabetes, are high-sugar foods.”

Interested in trying some gut-happy recipes? Try this Cauliflower Pilaf dish.

Want to learn more about the role of probiotics in diabetes? Read “Probiotics and Diabetes: Can Probiotics Help?”

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