Emerging molecular insights into the interaction between probiotics and the host intestinal mucosa

The genomics era has provided the opportunity for detailed investigations into the effects of the gut microbiota on the host mucosa. Bron, van Baarlen and Kleerebezem describe the features of probiotic bacteria that affect the mucosal immune system, and discuss the effect of the molecular characteristics of the host's mucosa on the response to these bacteria. Probiotic bacteria can modulate immune responses in the host gastrointestinal tract to promote health. The genomics era has provided novel opportunities for the discovery and characterization of bacterial probiotic effector molecules that elicit specific responses in the intestinal system. Furthermore, nutrigenomic analyses of the response to probiotics have unravelled the signalling and immune response pathways which are modulated by probiotic bacteria. Together, these genomic approaches and nutrigenomic analyses have identified several bacterial factors that are involved in modulation of the immune system and the mucosal barrier, and have revealed that a molecular 'bandwidth of human health' could represent a key determinant in an individual's physiological responsiveness to probiotics. These approaches may lead to improved stratification of consumers and to subpopulation-level probiotic supplementation to maintain or improve health, or to reduce the risk of disease.