Researchers from Kings College London have revealed that the makeup of bacteria in human feces may influence the level of dangerous fat in the body.
Results of the researchers study provided evidence that some of these bacteria are inherited, which could partly explain why obesity tends to be passed down to younger generations.
For the study, which was published in the journal Genome Biology, Michelle Beaumont and colleagues analyzed the stool samples of more than 1,300 twins who were part of the TwinsUK study, UK's largest twin registry for studies of aging-related diseases.
The researchers extracted DNA from the stool samples to know what fecal microbes were present. They also took into account different measures of obesity, such as body mass index (BMI), ratios of upper to lower body fat, and measurements of visceral fat, the abdominal fat that the body stores around important internal organs such as the pancreas, liver and intestines.
Beaumont and colleagues found that people with lower levels of visceral fat, or deep belly fat, tend to have a more diverse range of bacteria in their feces. Those with more visceral fat, on the other hand, were found to have lower diversity of bacteria.
"The key thing we found in our work is that the associations with the microbiome are much stronger with visceral fat than with any other measure of obesity," Beaumont said.
The researcher added that because visceral fat is highly associated with heart disease and metabolic diseases, studies should start investigating the actual measurement of fat instead of measurements as broad as BMI.
In earlier studies, researchers have found that people who have excess abdominal fat, including those with normal body weight, have higher risks for a range of life threatening diseases compared to those with higher BMI but have more even distribution of body fat, providing evidence that having normal weight is not the only measure for being healthy particularly for those with excess belly fat.
"Visceral fat is one of the fats that's hardest to remove," Beaumont said. "[It] has a much stronger association with the microbiome than BMI."
Researchers said that eating a broad diet that includes a variety of different food types may help boost the diversity of microbes in the feces.
Although the study has established a link between gut bacteria and visceral fat, it's not yet clear if changing the makeup of the microbiome will affect a person's weight.
