Table 1 Summary of key findings outlining the role of the gut microbiome in chronic disease.

Gut microbiome composition is significantly different in healthy individuals compared to affected individuals with a broad range of chronic diseases. Lower microbiome diversity appears to be a common theme across many of the diseases

Auto-immune diseases, in common with cardiometabolic diseases and irritable bowel syndrome, show low abundances of SCFA producing bacteria such as Bifidobacterium sp, Faecalibacterium sp, Roseburia sp, or Coprococcus eutactus

High abundances of pathogenic bacteria (such as E. coli, S. aureus, and C. difficile) are common in some of these diseases

SCFAs but also other microbial metabolites are involved in the health effects of gut microbiome composition and microbial metabolites can be better predictors of health outcomes than microbiome diversity

Gut microbiome composition is modifiable by various therapeutic strategies. Dietary interventions can result in robust changes in both gut microbiome composition and function and in the corresponding health effects