Impact of cafeteria diet and n3 supplementation on the intestinal microbiota, fatty acids levels, neuroinflammatory markers and social memory in male rats

Abstract

ObjectiveTo assess the effects of omega-3 (n3) supplementation on intestinal microbiota, fatty acids profile, neuroinflammation, and social memory of cafeteria diet (CAF)-fed rats. MethodsMale Wistar rats were fed with CAF for 20 weeks. Omega-3 (500 mg/kg/day) was supplemented between the 16th and 20th week. Colon morphology, intestinal microbiota composition, short-chain fatty acids (SCFA) and lipopolysaccharide (LPS) in the plasma, fatty acids profile, TLR-4 and claudin-5 expressions in the brain, and social memory were investigated. ResultsCAF reduced colon length, crypts’ depth, and microbiota diversity, while n3 increased the Firmicutes/Bacteroidetes ratio. CAF increased SCFA plasma levels, but n3 reduced butyrate and isobutyrate in obese rats. LPS was increased in CAF-fed rats, and n3 decreased its levels. In the cerebral cortex, n3 increased caprylic, palmitic, stearic, tricosanoic, lignoceric, myristoleic, and linoleic acids. CAF increased palmitic acid and TLR-4 expression in the cerebral cortex while decreasing claudin-5 in the hippocampus. In the social memory test, CAF-fed animals showed greater social interaction with no effect of n3. ConclusionsThe lack of n3 effect in some of the evaluated parameters may be due to the severity of the obesity caused by CAF. However, n3 reduced LPS levels, suggesting its ability to reverse endotoxemia.