The microbiota and infectious diseases

Abstract Studies over the last decade have transformed our previously simplistic view of microbes having only a pathogenic role in disease to a more robust understanding that they are critical for maintaining human health. Indeed, our microbiota—the collection of commensal organisms that live in and on each of us—contributes to nearly every facet of host physiology, from metabolic functions to maturation of the immune system and everything in between. Although the specific details of these host–microbe interactions are still being elucidated for most diseases, the marriage of clinical samples with animal models of disease have provided key insights. This chapter provides some general background on the microbiota, highlights a few examples of how the microbiota influences infectious diseases, and provides some context for how these findings may be clinically translatable.