Elucidation of the mechanisms of environmental adaptation of Lactobacillus gasseri in murine intestine

The mammalian gastrointestinal microbiota is robust to exogeneous perturbation and adapts to the intestinal environment, during which, advantageous mutations could be accumulated. Previous studies on such adaptation processes have predominantly been based on community composition. These studies have provided insights into the adaptation at the genus or species level, whereas the mechanism of gut microbial genome adaptation to the environments remains elusive. Therefore, in this study, we focused on the genomic mutation of gut microbes during intestinal colonization. To identify advantageous mutations, we inoculated Lactobacillus gasseri hypermutator strain (polC mutant) to germ-free (GF) mice. Feces were collected 1, 2, 3, 4, 6, 8, and 12 weeks after inoculation.