The gut microbiome.

Background: More than a trillion, mostly good, microbes live within our gastrointestinal tract and are responsible for vital metabolic, immune and nutritional functions. Dysbiosis, meaning a maladaptive imbalance of the microbiome, is associated with many common diseases and is a target for therapy.

Objective: This article provides an overview of the gut microbiome in health and disease, highlighting conditions such as Clostridium difficile infection, inflammatory bowel disease, irritable bowel syndrome, obesity and non-alcoholic fatty liver disease, with which dysbiosis is associated. Information about treatments that affect the gut microbiome, including probiotics and faecal microbiota transplant, are discussed.

Discussion: As our knowledge of the microbiome increases, we are likely to better understand the complex interactions that cause disease, and develop new and more effective treatments for many common conditions.