Medical News

Researchers uncover the important function of bacterial intercourse within the evolution of the mammalian microbiome

In a pioneering research printed within the Proceedings of the Nationwide Academy of Science – United States, the analysis group led by Isabel Gordo, of the Instituto Gulbenkian de Ciência (IGC) (Portugal), in collaboration with researcher Michael Lässig of the College of Cologne (Germany) have used wholesome mice to review intestinal colonization in actual time and have found an important function for bacterial intercourse within the evolution of the microbiome of mammal. This discovery represents a paradigm shift and opens the potential of designing phage-targeted therapies to deal with the after-effects of antibiotic an infection and use, in addition to antibiotic-resistant micro organism. .

Most of our data of bacterial intestinal colonization comes from research of pathogenic micro organism in extremely synthetic laboratory fashions or in pathological contexts. Classical experimental fashions, which give attention to infections by pathogenic micro organism and steady antibiotic remedy, haven’t detected horizontal gene switch (HGT) directed by phage and counsel that micro organism colonizing gut evolve primarily by accumulation of mutations. In a shocking discovery, the work of IGC researchers now reveals that the HGT, and never the mutations, is the primary evolutionary mechanism behind the rhythm and consequence of bacterial evolution in a wholesome digestive tract.

Escherichia coli is a standard colonizer of the human gut in addition to a possible pathogen. The results of colonization is vastly influenced by the completely different speeds and modes of evolution of this opportunistic bacterium. colican evolve by mutations, that are then inherited by daughter cells, or by a strategy of recombination, that’s, the bacterial intercourse, by which the genetic materials is shared between unrelated people. Within the gut of mice and people, this switch of genetic materials entails temperate bacteriophages (phages), viruses that infect micro organism and combine into the bacterial chromosome as prophages, a course of known as lysogeny. Prophages can then extract (in addition to their genetic data) from bacterial DNA and infect different micro organism within the intestinal microbiome.

Nelson Frazão, a postdoctoral researcher in Isabel Gordo's laboratory and junior creator of the research, says, "phages typically categorized as egocentric particles reveal their altruistic facet within the intestine, offering a metabolic profit to their host bacterial, to overcome and colonize the intestine ". The phage genetic materials transferred permits micro organism to entry particular carbon sources current within the gut, which is a well being profit for invading phage (lysogenic) micro organism.

We discovered that the classical evolutionary mannequin didn’t apply and that, in truth, horizontal gene switch vastly outweighs the contribution of evolution via of the buildup of mutations within the gut of a wholesome mouse. "

Isabel Gordo, investigator

"By way of this work, we now higher perceive the functioning of the evolution in regular hosts and in good well being," stated Nelson Frazão, starting creator of the publication.


Instituto Gulbenkian de Ciência (IGC)

Journal reference:

Frazão, N. et al. (2019) Horizontal gene switch cancels the mutation in Escherichia coli colonizing the mammalian gut. PNAS.