Mammals mold their Microbiome for disease prevention

Intestinal microbes are well known to contribute to health and disease, but what is less clear is how guests control the intestinal microbes. A study published Wednesday in Cell Host & Microbe now that mice and humans produce small molecules (microRNAs) of your gastrointestinal tract, which are eliminated in the feces, to regulate the composition of microbes in the gut, and therefore protect against bowel disease, like colitis.

“Since the intestinal microbes play an important role in the metabolism of the host and immunity, as well as disease, it is important to understand the mechanisms by which the microbiota is regulated by the host and identify ways in which manipulate the Microbiome”, says the lead author of the study, Howard Weiner. “Our findings reveal a host defense mechanism and point to the microRNAs as a strategy of manipulation of the Microbiome to the health of the host,” he added.

On the basis of previous studies, Weiner and co-author Shirong Liu, both Hospital Brigham and women and the school of medicine from Harvard University, both in the United States, suspected that the microRNAs could play a key role in this process.

These small molecules regulate the activity of the gene in a variety of species, from viruses to humans, and they have been implicated in intestinal diseases such as colorectal cancer. In addition, they may enter and control the expression of genes in the mitochondria, cellular structures that arose evolutionarily from the bacteria.

In the new work, scientists found that the microRNAs produced by intestinal cells in mice and humans come into bacteria, regulate the activity of the bacterial genes and shape the composition of intestinal microbes.

Mice that were deficient in intestinal microRNAs showed an altered intestinal Microbiome and were more susceptible to colitis. But the transplant of intestinal microRNAs in normal mice deficient rodents in microRNA restored the normal composition of intestinal microbes and protected against damage to the colon.

Researchers are further investigating the molecular mechanisms underlying, hoping finally to apply these findings to the clinic.

“Our study suggests that the ability of the host to control intestinal microbes probably gives organisms an evolutionary advantage, i.e. the prevention of diseases such as colitis and colorectal cancer – says Weiner-. “We are optimistic that it will be possible one day take advantage of this mechanism of natural host defense by the administration of microRNAs as therapeutic compounds to improve health and treat disease”.