Ecological and molecular perspectives on responders and non-responders to probiotics and prebiotics.

[Display omitted] • Responder-status to probiotics and prebiotics vary among individuals. • Niche-based processes can predict probiotic colonization success in the microbiota. • Response to prebiotics is predictable by key enzyme gene abundance in the microbiota. • Interventions for the gut microbiota require both ecological and genetic perspectives. Bifidobacteria are widely used as a probiotic for their health-promoting effects. To promote their growth, bifidogenic prebiotics, including human milk oligosaccharides (HMOs), have been added to supplements and infant formula. However, the efficacy of both probiotic and prebiotic interventions is often debated, as clinical responses vary significantly by case. Here, we review clinical studies that aimed to proliferate human-residential Bifidobacterium (HRB) strains in the gut, and we highlight the difference between responders and non-responders to such interventions through an ecological, niche-based perspective and an examination of the prevalence of genes responsible for prebiotic assimilation in HRB genomes. We discuss the criteria necessary to better evaluate the efficacy of probiotic and prebiotic interventions and the recent therapeutic potential shown by synbiotics. [ABSTRACT FROM AUTHOR]