Broccoli consumption attenuates inflammation and modulates gut microbiome composition and gut integrity-related factors in mice fed with a high-fat high-cholesterol diet

Abstract

Background: Nonalcoholic fatty-liver disease (NAFLD) is a global health problem associated with gut dysbiosis and intestinal permeability. Broccoli is a natural source of bioactive phytochemicals, characterized by health-promoting properties. Objective: This study evaluated the effect of broccoli florets and stalks on liver fat accumulation, inflammation, gut microbiome, and intestinal barrier integrity. Design: Male C57BL/6J mice (n = 32, 8-week-old) were fed with a high-fat high-cholesterol diet (HFCD) with/without 15% broccoli (florets or stalks) for 7 weeks. Liver damage was evaluated by changes in glucose response and histological and biochemical parameters. Protein and gene expressions related to liver inflammation were examined. The effect of broccoli on microbiota population together with genes related to barrier integrity in the gut was investigated. Results: Dietary broccoli improved the glycemic response assessed by oral glucose tolerance test (OGTT). Histological evaluation showed no change in hepatic steatosis. Broccoli consumption also attenuated inflammation as revealed by lower inducible nitric oxide synthase (iNOS) and serum amyloid A1 (SAA1) expression levels in broccoli-supplemented groups. Gut microbiota analysis demonstrated elevated Acidifaciens and reduced Mucispirillum schaedleri abundance in the stalks group, whereas Proteobacteria strains abundance was increased in the florets group. Gut integrity remained unchanged. Conclusion: Broccoli supplementation improves glucose tolerance, attenuates liver inflammation, and alters microbial composition, but does not affect gut integrity. This research provides new evidence on the effects of dietary broccoli under HFCD.