Scientists Reveal the Link between Weight Gain and Intestinal Bacteria

According to the Centers for Disease Control and Prevention more than 60 percent of U.S. adults are overweight or obese, and the trend continues with our children and teens. Statistics show that nearly 20 percent of 6- to 11-year-olds and roughly 17 percent of 12- to 19-year-olds are overweight. As a result, more and more people are suffering from obesity-related illnesses such as diabetes, high blood pressure, heart disease and stroke. But while diet and lifestyle habits play a significant role in healthy weight management, scientists now believe that the unique bacterial population in the human digestive tract may also have a considerable effect on our weight loss efforts.

As soon as we are born, trillions of bacteria begin to take up residence in the gut. And by the time we learn to walk this flourishing community is essentially complete, with microbial cells outnumbering human cells by a factor of ten to one. Included among the many jobs performed by our intestinal bacteria is that of extracting calories and nutrients from the foods we eat and storing them for later use, as well as making sure there is sufficient nourishment to produce new bacteria to perform the same job. This bit of information is particularly interesting to researchers studying why some people as opposed to others tend to gain weight more easily.

New Evidence Supports the Bacteria Connection

Recently scientists at the Washington University School of Medicine in St. Louis tracked the weight loss efforts of 12 obese adults for more than a year, all of whom were prescribed either a low-calorie, low-fat diet or a low-calorie, low-carbohydrate diet. Regardless of what each participant ate, however, bacterial population in the gut clearly impacted whether he or she was able to lose weight successfully and maintain a healthy body weight.

Researchers found that both the type and quantity of microbes residing in the intestines of normal weight adults differs significantly from those who are obese, which may help explain why some people have more difficulty losing weight even when they follow a healthy diet and exercise on a regular basis. Specifically, individuals who are prone to weight gain tend to have greater numbers of gut bacteria called firmicutes and fewer numbers of another type of bacteria called bacteroidetes. These two major groups account for the majority of the microbes in the human digestive tract—more than 90 percent, according to the study. What’s more, evidence revealed that as participants began to lose weight, the amount of both types of bacteria shifted; bacteroidetes became more abundant, while the number of firmicutes lessened.

Based on these findings, lead investigator Dr. Jeffrey Gordon theorized that “…differences in our gut microbial ecology may determine how many calories we are able to extract and absorb from our diet and deposit in our fat cells.” This means that depending upon intestinal bacteria levels, not every individual will absorb the same number of calories from a specific food or meal.

The Power of Probiotics

As studies continue to reveal the link between gut bacteria and obesity, natural health practitioners emphasize the importance of daily supplementation with beneficial bacteria called probiotics. Translated literally, the word probiotic means “for life”,which is appropriate because these microscopic organisms found in the intestines work diligently to crowd out harmful, disease-causing bacteria and promote a balanced bacterial environment that is conducive to healthy weight management and overall well being.

Consisting mainly of Bifidobacteria (most prevalent in the large intestine) and Lactobacilli (most prevalent in the small intestine), this ideal balance is often upset by factors such as poor diet, stress, illness and antibiotic use, which is why taking a daily probiotic supplement is considered essential for healthy living.

Hope for Healthy Weight Management

Although still a relatively new theory, the idea that altering the bacterial make-up of our intestines may indeed boost our weight loss efforts holds promise for many Americans who struggle daily with the consequences of overweight and obesity. For this reason, more and more health practitioners recommend adding a daily probiotic supplement to a healthy weight management program that includes regular exercise and a low-calorie diet.