Figure 3.

Different degrees of potential causal relationships between human disease and altered microbiota composition. The human gut microbiota is a stable ecosystem, which is dependent on environmental and genetic factors. Under healthy conditions, gut microbiota lives in symbiosis with its host. Different human disease states have been associated with altered fecal microbial composition; however, at this moment, it not known whether this is merely a reflection of the underlying disease. Moreover, it is very likely that the intestinal microbiota are not equally important in all human disease states; thus, their role in the pathophysiology may vary from disease modifiers to causal drivers. Abbreviations: ESBL, extended-spectrum beta-lactamase producing Enterobacteriaceae; VRE, vancomycin-resistant enterococci; IBD, inflammatory bowel disease; IBS, irritable bowel syndrome; T1D, Type 1 diabetes mellitus; T2D, Type 2 diabetes mellitus.