The intestinal microbiota is a collection of billions of microorganisms that forms after birth in humans and animals. While we know that the environment, and in particular diet, has a major influence on the formation and composition of the microbiota, the influence of genetics is still debated. For the first time, scientists at INRAE have demonstrated experimentally, in pigs, that the formation of intestinal microbiota is partly heritable. They selected 2 lines of pigs for 2 types of intestinal microbiota characterized by their bacterial composition. The results, published in the journal Microbiome, show that the frequency of each type of microbiota increases from generation to generation in each line. Another finding is that, for one type of microbiota, selection favors faster growth in piglets. These results open up new prospects for taking intestinal microbiota into account in animal selection schemes for more sustainable and resilient breeding.

The intestinal microbiota influences the characteristics of its host in a wide variety of ways. One of the most important roles played by the microbiota is its ability to break down feed that cannot be digested by the host itself, thus facilitating its utilization. This raises the question of the microbiota's influence on the feed efficiency (1) of farm animals. INRAE researchers have published a study in the journal Scientific Reports showing the existence of a relationship between the composition and function of this microbiota and the feed efficiency of laying hens.