Weight loss and microflora

Scientists have learned to "fake" the benefits of dietary restrictions

Anna Kerman, XX2 century

It is known that mice whose diet is limited in calories live longer than mice who eat normally. In addition, animals that are "on a diet" are, on average, slimmer and healthier than their relatives. Recently, scientists have finally been able to solve this riddle. It turned out that it was the intestinal microbiota and its effect on the immune system. The researchers also found chemical compounds acting in much the same way as dietary restrictions. In the future, this finding may lead to the emergence of fundamentally new approaches to the treatment of obesity.

A group of scientists led by Professor Mirko Trajkovski from the University of Geneva, "putting" mice on a 30-day "diet", found that the amount of brown adipose tissue in the animals increased. Brown adipose tissue is involved in the burning of fat reserves and plays an important role in the process of weight loss.

Then the researchers transplanted the microflora of this group of mice to other mice grown in sterile conditions and did not have their own symbiont bacteria. After this procedure, more brown adipose tissue also appeared in the organisms of the mice of the second group. In addition, the recipient mice lost weight, although they were not restricted in their diet - that is, the appearance of a specific microbiota alone had a beneficial effect on the animals' body.

After studying the microbial communities formed in the gastrointestinal tract of mice, scientists found that the bacteria that underwent the "diet" began to produce less toxic lipopolysaccharides. When the levels of lipopolysaccharides in the blood of experimental animals were artificially increased to normal values, the benefits of dietary restrictions practically disappeared.

Lipopolysaccharides of bacterial origin provoke the immune system by activating toll-like receptor 4 (TLR4). By experimenting with genetically modified mice whose immune cells did not carry these receptors, the scientists were able to reproduce the effect of the "diet". "It is obvious that the immune system not only fights infections, but also plays a key role in the management of metabolic processes," says Trajkovski. It's not just an increase in the amount of brown adipose tissue and weight loss: experimental animals also tolerated the cold more easily, responded more actively to insulin, and their liver coped better with fats and carbohydrates.

Figure from the article Fabbiano et al. Functional Gut Microbiota Remodeling Contributes to the Caloric Restriction-Induced Metabolic Improvements Author links open overlay panel, published in the journal Cell Metabolism – VM.

Now a group of researchers led by Professor Trajkovski set out to study two compounds: one of them directly reduces the production of toxic lipopolysaccharides by bacteria, and the second blocks toll-like receptors activated by lipopolysaccharides. Both substances – it has already been proven – affect the health of experimental mice in about the same way as dietary restrictions. The scientists themselves believe that their discovery has significant potential. Perhaps, thanks to him, in the future there will be drugs on pharmacy shelves that can imitate a diet without having to adhere to it.

Portal "Eternal youth" http://vechnayamolodost.ru