The microbiota, the complex microbial community that we host in our gut, influences a number of different processes in our bodies, including metabolism and immunity. A change in the composition of the gut microbiota has been associated with a number of diseases. As we learn more about how these are linked, new possibilities arise for developing therapies based around restoring the composition of the microbial community to our benefit.  But to be effective, we need to understand how these bacteria colonise our gut – something we know little about.

Nathalie Juge from the Institute of Food Research has been studying this, focusing on bacteria associated with the mucus layer produced by the gut lining. Working in collaboration with The Genome Analysis Centre, the University of Nebraska Lincoln, and the University of Alberta, she has been studying the gut bacteria Lactobacillus reuteri. 

L. reuteri are commonly found in the microbiota of many different vertebrate animals, and have been well studied as a ‘model’ gut bacteria. By comparing the genomes of different strains of these bacteria, the researchers recently showed that during evolution, the bacteria diversified into different groups, or clades, and that these were specific to the host organism. This means that only rodent-specific L. reuteri could colonise mice, for example.

In a new study, published in the journal BMC Genomics Nathalie Juge and her team looked at L. reuteri strains found in pigs, to find out why these strains specifically colonise these animals.