The human body, we now know, exists in a fundamentally (0) SYMBIOTIC (SYMBIOSIS) relationship with the trillions of microorganisms that populate its gut, skin and respiratory tract. The sheer 1DIVERSE of this internal ecosystem is staggering, comprising thousands of species that are overwhelmingly benign and only rarely 2PATHOGEN. Disruptions to this balance appear to modulate almost every aspect of 3IMMUNE regulation, and emerging evidence ties microbial imbalance to chronic 4INFLAME disorders as varied as Crohn's disease, atopic eczema and certain autoimmune conditions. The community's role in 5METABOLISE processes has likewise proved central, influencing how the body extracts energy from food and processes pharmaceuticals. Clinicians are accordingly being urged to reconsider the routine 6PRESCRIBE of broad-spectrum antibiotics, since the collateral damage to beneficial microbes may contribute to long-term 7RESIST. Whether the field's more ambitious 8THERAPY claims will be borne out remains to be seen, but the underlying shift in medical thinking is now firmly established.