In the human intestine, bacteria slumber, which ensure the development of immune cells - and which in turn prevent the formation of fat cells. However, a strongly sugar -containing diet can reduce the number of these microbes, as Yoshinaga Kawano from Columbia University in New York and his team describe in a study in the journal "Cell" from August 2022. With experiments on mice, they showed how nutrition, intelligence and special immune cells are related and protect against obesity and other metabolic diseases.
The metabolic syndrome includes several health states such as high blood sugar levels or obesity, which together increase the risk of cardiovascular diseases and diabetes. Kawano and his colleagues now found that certain intestinal bacteria in mice help to reduce the risk factors for a metabolic syndrome. The microbes ensure an increase in special T helper cells, the so-called TH17 cells. As the researchers discovered, these immune cells cause less fat to be absorbed in the intestine.
If the scientists fed the mice a high-fat and high-sugar diet, the helpful bacteria in the intestine were killed. However, microbiotic preparations prevented the mice from getting fatter or developing a metabolic syndrome despite the high-fat and high-sugar diet. A closer look revealed how the overweight came about before: the high sugar content promoted the growth of bacteria of the family Erysipelotrichaceae, which in turn killed the immune-regulating bacteria. When the mice stopped eating sugar, they also stopped developing obesity and metabolic syndrome. However, only if the animals still had TH17 cells produced by bacteria. This shows that sugar apparently makes you fat not only because of the calories, but also because of its effect on the microbiome of the digestive tract.
© Springer Nature 10.1038/D41586-02775-9, 2022
