The role of enteric infection and the microbiome in human health and disease

One of the many benefits the gut microbial community provides to the human host is protection against infection by external pathogens (colonization resistance). Strategies to bolster this protective effect may have important implications both in the developing world, where diseases of the gastrointestinal tract still represent significant healthcare problems, and for combating food-borne and travel-associated illnesses in more developed countries. Potential strategies have included promoting overall microbiome health and the populations of 'good' microbes (primarily bacteria and yeast) using probiotics and prebiotics, but thus far there is little evidence that these can have a clinically significant effect in the prevention or treatment of disease. However, certain levels of exposure to food-borne and environmental microbes, particularly early in life, appear essential for innate and adaptive immune development.