Can the bacteria in your intestines affect your health?

In recent years, researchers have become increasingly interested in exploring the link between the more than 100 trillion bacteria that live on and in the human body, known as the human microbiome, and a variety of health issues. Several recent studies have found connections between the type and number of bacteria in the intestines and the risk of diabetes and obesity, which can increase your risk for other serious health conditions including heart disease, stroke, certain cancers and arthritis. But why do bacteria in your gut affect your health?

You may know that the bacteria in your intestinal tract help you digest the food you eat, but researchers have recently found that some strains of these bacteria also appear to affect the way the body stores fat, reacts to the hormones that signal feelings of hunger or fullness in the brain, and regulate blood glucose levels.

Lean or fat: how gut bacteria can affect body weight

Researchers at the Washington University School of Medicine, led by Jeffery Gordon, MD, transferred intestinal bacteria from human twins, one of whom was obese and the other of whom was slender, into mice that were raised so that they did not have any bacteria on their bodies. Both sets of mice ate the same diet, but those that received the bacteria from the obese twins got heavier and had more body fat than the mice that received the bacteria from the slender twins. The researchers then performed the same study, but instead of keeping the two sets of mice in separate cages, they put them together. This time, all the mice stayed lean because the mice with the bacteria from the obese humans picked up bacteria from their lean cage mates. The bacteria from the lean humans appeared to counteract the effects of the bacteria from the obese humans.

Another study by researchers at the NYU Langone Medical Center led by Martin Blaser, MD, director of the institution’s Human Microbiome Program, found an additional link between intestinal bacteria and weight. The study suggested that the bacteria Helicobacter pylori, which humans once had large numbers of in their digestive tracts, may play a role in regulating the hormone that stimulates feelings of hunger. Since better sanitation has lowered the number of these bacteria in the human gastrointestinal system, the hormone may be overproduced, making people feel hungry even when they are adequately nourished.

The microbiome-diabetes link

Researchers have also found links between intestinal bacteria and type 2 diabetes. A recent study led by Yalcin Basaran, MD and presented at the annual joint meeting of the International Society of Endocrinology and the Endocrine Society, found that study participants who were obese or had type 2 diabetes had significantly lower numbers of the most common types of intestinal bacteria.

Other studies have suggested that changes in the makeup of intestinal bacteria may be linked to the risk of developing type 1 diabetes and that controlling the number of certain types of bacteria can help reduce insulin resistance, a factor in the development of type 2 diabetes.

Bacteria are only one part of the health equation

While these early studies suggest that intestinal bacteria may play an important role in weight gain and the development of diabetes, genetics and lifestyle factors, including diet and exercise, are also key parts of the equation. Understanding the latest research and scientific developments can help you develop a personalized plan to gain control of the factors that increase your risk of diabetes and other health problems.

A health advisor can keep you up-to-date on the latest developments in the field of health and wellness and help you create a strategy that addresses your personal health risks and goals.