Chronic alcohol consumption disrupts the gut microbial and metabolic landscapes

Alcohol use disorder (AUD) increases the incidence of infections, organ damage, and cancers. One reason for these health problems may be chronic inflammation caused by long-term alcohol use. Previous research has shown that chronic alcohol consumption (CAC) can alter important immune cells, macrophages and monocytes, making them more likely to trigger excessive inflammatory responses.
Researchers used a non-human primate model of ethanol self-administration to characterise alcohol-induced alterations in gut microbes and associated metabolomes. The microbiome was analysed using 16S rRNA sequencing, and changes in metabolites were assessed.
After 12 months of alcohol use, the researchers found lower levels of beneficial gut bacteria that normally produce short-chain fatty acids (SCFAs), along with reduced levels of these important compounds. Because SCFAs help maintain a healthy gut lining, their reduction may weaken the intestinal barrier and make it easier for harmful substances to enter the bloodstream. The study also identified other changes consistent with increased inflammation in the body.
These findings suggest that long-term alcohol consumption disrupts the normal balance of gut bacteria, leading to changes in important substances in the gut and bloodstream. These changes may alter the behaviour of monocytes, a type of immune cell, causing them to become overactive or function abnormally.
Source: Blanton, M.B., Napier, E.G., Keen, K.E., Stuart, E.V., Cinco, I.R., Hemati, H., et al. (2026) Chronic alcohol consumption disrupts the gut microbial and metabolic landscapes. Frontiers of Microbiology, 17, 1794794.