Newswise — Dear Mayo Clinic: My friend insists that taking a probiotic supplement helped her lose 50 pounds by controlling her gut bacteria. Will taking probiotics along with a balanced diet and exercise help me lose weight?
Answer: It is true that the number of gut bacteria in obese people differs from that of lean people. But we still don't know if this difference contributes to obesity or is a consequence of it.
To date, research has not yielded clear answers. Although taking probiotics is unlikely to cause harm, they may not help fight obesity either.
First and foremost, it is important to know that weight gain is mainly due to an energy imbalance. Where weight increases when you eat more calories than the body burns. There is some evidence that bacteria in the gut play a role in how well the body extracts energy from food that reaches the small intestine.
The digestive tract, also known as the intestine, contains trillions of bacteria. Many of these bacteria play beneficial roles in the body, including metabolizing nutrients from food. And while many of the bacteria in the gut are valuable, some are not. Some studies have been done on how an imbalance between good and bad gut bacteria contributes to certain medical disorders.
Eating foods like yogurt and sauerkraut that contain probiotics — a type of “good” bacteria — or taking a probiotic supplement has health benefits. Although more research is needed, there is some evidence that probiotics improve gut health.
So far, however, the only studies showing convincing results are that altering the composition of gut bacteria — sometimes called gut microbiota — affects weight, using germ-free mice. As for humans, data is still murky on the role of probiotics in aiding weight loss in humans.
An analysis of the results of published research studies that investigated probiotics and weight loss did not lead to clear answers. In part, this is because research methods varied widely among these studies. As well as being run on a different set of probiotics.
It is clear here that the most important factor determining the composition of the intestinal microbiome is diet. But, again, this leads us to ask which comes first. Does obesity lead to a specific microbiome? Or does a certain type of micronutrient lead to obesity? Up to this point, this is still unknown.
What is known is that you can take some steps to maintain a healthy intestinal microbiome that will help you in your weight loss journey. For example, eating plenty of fruits and vegetables has been shown to help the good bacteria in your gut thrive. It may also help fill you up and reduce overeating of snacks and other unnecessary calories. Reducing fat, sugar, and animal sources of protein can also help maintain a healthy intestinal microbiome. Research has shown that diets rich in these foods are linked to building more unwanted bacteria.
Taking probiotic supplements also improves the health of your intestinal flora, but it's not clear what role these supplements play in weight loss. The most reliable way to lose weight is to eat a healthy diet and exercise regularly so that you burn more calories than you consume. I also always recommend directing specific questions about diet and exercise to your primary care team.
Dr. Mira Shah , MD, Endocrinology, Diabetes and Metabolism, Mayo Clinic, Rochester, MN
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