Antibiotics contribute to obesity 06.09.2012

Perhaps the obesity epidemic around the world is not only due to fatty foods and a sedentary lifestyle. Apparently, one of the reasons is the use of a large number of antibiotics, which upset the balance of the intestinal microflora. To date, this scenario is only a hypothesis, strongly supported by two recent studies.

Recently, the microbiome - the collection of bacteria, viruses and fungi that inhabit the human body - has attracted increasing attention from scientists. This is not surprising, since the number of microbiome is 10 times greater than the number of cells that make up the human body. Numerous studies have found strong links between microbiome disturbances and an increased risk of developing a range of diseases, from cancer and autism to heart disease and obesity.

Researchers at New York University decided to find out if the massive increase in body weight of factory-raised livestock is the result of changes in the microbiome. The fact is that one of the most important functions of the microbiome is participation in the breakdown of nutrients and regulation of metabolism. Nowadays, farmers give antibiotics to animals not only to prevent infectious diseases, but also because, for some reason, regular low doses of antibacterial drugs accelerate the growth and increase in body weight of animals.

Experiments have shown that dietary supplementation of mice with low doses of different types of antibiotics consistently resulted in a 15% increase in body fat. The study of the microbiome of animals revealed changes in the ratio between different types of bacteria inhabiting the gastrointestinal tract. At the same time, analysis of the genetic profile of mice showed a change in the activity of genes responsible for the breakdown of carbohydrates and the regulation of blood cholesterol levels.

Scientists have suggested that similar changes may occur in the human body, which, however, are difficult to track at the level of the intestinal microbiome. To confirm this hypothesis in a second study, the authors analyzed population trends in a group of 11 British children. It turned out that for children exposed to antibiotics at the age of less than 000 months, there was a small but stable increase in average body weight at an older age. Apparently, antibiotics taken at an early age disrupted the formation of the microbiome and the formation of metabolism.

The researchers are currently conducting new series of experiments in which mice will receive higher doses of antibiotics for short periods of time, which is in line with the treatments that people take in reality. They also plan to study the effects of very low doses of antibacterial drugs, similar to those ingested by human consumption of industrially produced meat and dairy products. Another issue that needs to be studied is the possibility of transferring changes in the microbiome to the next generations. It is possible that in this case the effect of antibiotics is cumulative.