Omega-3 polyunsaturated fatty acids and gut microbiota

Oral intake of n (omega)-3 polyunsaturated fatty acids (PUFAs) is associated with changes to gut microbiota. We review recent findings from 2024 onwards, which build the scientific case that changes to bacterial abundance, and their metabolites, contribute to the health benefits associated with n -3 PUFAs.

There are now multiple studies in rodent disease models that demonstrate that n -3 PUFAs do not significantly alter bacterial diversity but, instead, alter abundance of several species that are implicated in short-chain fatty acid synthesis, in a model-specific manner. Limited intervention studies in humans, backed by larger observational studies, concur with the preclinical findings. Importantly, faecal transplantation experiments have confirmed that n -3 PUFA-induced changes to gut microbiota are causally related to reversal of the disease phenotype in two rodent models. In-vitro colonic models are now being used to understand the mechanism(s) underlying n -3 PUFA-induced changes to the gut microbiota and metabolome.

Despite emerging proof that the gut microbiota contributes to n -3 PUFA activity in animal models, human data are sparse. It remains unclear how n -3 PUFAs affect changes to the gut microbiota or whether n -3 PUFA metabolism by gut microbes contributes to the host metabolome.