DHA (Omega-3) May Help Protect Gut Health by Reshaping Gut Bacteria

This laboratory study examined how DHA, a long-chain omega-3 fatty acid found in fish oil, affects colon inflammation in mice with chemically induced colitis (a model used to study inflammatory bowel disease). Researchers gave DHA to mice before and during colitis induction and measured changes in body weight, colon damage, and gut bacteria.

Mice that received DHA showed less severe colitis overall, including less weight loss, less colon shortening, and reduced tissue damage. Genetic sequencing of gut bacteria showed that DHA increased populations of beneficial bacteria, including Bifidobacterium species.

To test whether these benefits depended on gut bacteria, researchers removed the animals’ microbiota using antibiotics, which canceled out DHA’s protective effects. When they transferred gut bacteria from DHA-treated mice into other mice, those animals also became more resistant to colitis. DHA-treated mice also had stronger intestinal barrier proteins and more regulatory immune cells in the colon, but only when gut bacteria were present.