Elucidation of intestinal colonization mechanism for Japanese-derived Bifidobacterium longum by comparative genomic analysis.

Bifidobacterium longum, a member of genus Bifidobacterium, is known to have beneficial effects such as food digestion, nutrient absorption, and immunostimulation in the human intestine. Since it has been reported that genome sequences of B. longum, which colonize in the human intestine, are different in each individual, "unique" B. longum may stably colonize in each intestine and function as probiotics. Therefore, exogenous B. longum that are consumed by the yogurt or supplement does not be expected to colonize in the intestines. If the mechanism of B. longum colonization in the human intestine can be clarified, it becomes possible to control the abundance of B. longum in the intestine and maintain the human health. In this study, in order to clarify the mechanism of B. longum colonization, we explored the genes or genome regions those are involved in colonization of B. longum into the human intestine.