Probiotics are more likely to be therapeutically effective along mucosal surfaces where microbes meet epithelial cells.

“My hunch or my assumption is that most of the effect that one would see from exogenous bacteria, for example, from precision probiotics would be expected to exert along the mucosal surfaces where the microbes meet the epithelial cells, where they adhere to the epithelial cells or to the mucus layer, and where the distances are such that secreted molecules could reach their destination without having to pass through this giant ocean.”