Gut microbiota

What is gut microbiota in bipolar disorder?

Gut microbiota involves a dynamic community of microorganisms that inhabits the human body, and changes in response to intrinsic and extrinsic factors. This community includes bacteria, archaea, microbial eukaryotes, fungi, and viruses, and so it is critical in maintaining healthy physiology, Disruption to it has been shown to have a pivotal role across a range of medical conditions including inflammatory bowel disease, metabolic diseases, cancer, and chronic pulmonary diseases.

Studies are now investigating how the gut microbiota can influence the brain. The mechanisms by which intestinal microorganisms could be linked to emotional and cognitive functions of the brain are not fully understood, but they are thought to include the vagus nerve, gut hormone signalling, the immune system, tryptophanmetabolism, and microbial metabolites such as short-chain fatty acids.

What is the evidence for changes in gut microbiota in people with bipolar disorder?

High quality evidence finds increased proxy biomarkers of gut-microbial diversity (gut dysbiosis), in particular antibodies against bacterial endotoxins and sCD14, in people with bipolar disorder relative to controls. Lower quality evidence finds the proxy biomarker zonula may also be increased in bipolar disorder. There was overall reduced gut biodiversity in medicated versus non-medicated patients.

Moderate to low quality evidence finds the family Ruminococcaceae, genus Faecalibacterium, and species Faecalibacterium prausnitzii may be reduced in bipolar disorder, while genera Bacteroides or Bacteroides-Prevotella group species may be elevated compared to controls.

December 2021

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Last updated at: 6:21 pm, 9th December 2021
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