Discover why bacteria determine the size of your waist

Recent research suggests that the size of the waist depends to a certain extent on bacteria that inhabit the intestine. How is it possible?
In a study involving 900 Dutch adults, it was found that some intestinal bacteria could help determine not only body fat levels, but also blood concentrations of HDL (good) cholesterol and triglycerides.

This is the first study to offer "solid evidence" linking intestinal bacteria with cholesterol and triglyceride levels, said Jingyuan Fu, associate professor of Genetics at the University Medical Center of Groningen, in the Netherlands.

Although it is too early to recommend the use of probiotic supplements for the prevention of heart disease, these results add to the growing evidence that the gut microbiome plays an important role in human health.

The term "microbiome" refers to the billions of bacteria and other microbes that naturally inhabit the intestine.

Recent research revealed that these microorganisms do much more than support good digestion: they help in everything from immune function to the metabolization of drugs for the production of vitamins, anti-inflammatory compounds and even chemicals that transmit messages between brain cells.

Studies also suggest that when the microbiome lacks diversity it can contribute to health problems such as obesity, asthma and type 1 diabetes.

This latest study "provides important information for our understanding of the gut microbiome and health risks, in particular, of cardiovascular diseases," said Dr. Lea Chen, gastroenterologist and microbiome researcher at the Langone Medical Center at the University of New York. (NYU) in the city of New York.

The findings, which appear in the September 10 issue of Circulation Research, were based on 893 adults between 18 and 80 years old. Fu's team analyzed fecal samples to obtain a snapshot of each person's gut microbiome.

In general, the researchers found 34 types of bacteria that were related to triglycerides and HDL levels of people, and with body mass index (BMI), a measure of weight in relation to height.

The researchers estimated that the intestinal microbiome was responsible for between 4% and 6% of the variation in body mass index, triglyceride and HDL levels of the group that participated in the study.

For now, Chen suggests that people follow proven eating habits, such as a diet rich in fruits, vegetables, fish, high-fiber grains and other "whole" foods.