Docosahexaenoic acid-rich fish oil prevented insulin resistance by modulating gut microbiome and promoting colonic peptide YY expression in diet-induced obesity mice

It is unclear how docosahexaenoic acid(DHA)improves insulin resistance via modulating gut microbiome in obese individuals.We used diet-induced obesity(DIO)mice as a model to study the effects of DHA-rich fish oil(DHA-FO)on host metabolic disorders and colonic microbiome.DHA-FO reduced fat deposition,regulated lipid profiles and alleviated insulin resistance in DIO mice.Probably because DHA-FO prevented the permeation of lipopolysaccharide across intestinal epithelial barrier,and promoted peptide YY(PYY)secretion via the mediation of short chain fatty acids receptor(FFAR2)in colon.Furthermore,DHA-FO might regulate PYY expression by reversing microbial dysbiosis,including increasing the abundance ofAkkermansia muciniphila and Lactobacillus,and suppressing the growth of Helicobacter.DHA-FO also altered gut microbial function(e.g."linoleic acid metabolism")associated with PYY expression(r>0.80,P<0.05).Herein,DHA-FO enhanced insulin action on glucose metabolism by altering gut microbiome and facilitating colonic PYY expression in DIO mice.