Dietary broccoli improves markers associated with glucose and lipid metabolism through modulation of gut microbiota in mice

Abstract Objective Broccoli a "functional food", which contains bioactive compounds and phytochemicals have beneficial health promoting effects. This study aimed at investigating the effects of broccoli consumption on lipid and glucose metabolism and gut microbiota. Design Male C57BL/6J mice 7-8 weeks old were fed ad libitum with a normal diet supplemented with or without 10% (w/w) broccoli florets or broccoli stalks. Oral glucose tolerance tests were performed at week 15. After 17 weeks, blood and tissues were collected. Serum parameters, histology, genes and protein expression, together with intestinal microbiota composition, were evaluated. Results Stalk supplementation led to reductions in fasting glucose levels, serum insulin and HOMA-IR index. Liver enzymes improved in both experimental groups and broccoli florets decreased total triglycerides. The stalks group had elevated fatty acid oxidation related genes and proteins (AMPK, PPARα and CPT-1).Diverse microbiota population was observed in both broccoli groups. Broccoli stalks were found to be richer in Akermansia muciniphila while broccoli florets reduced Mucispirillum schaedleri abundance and increased bacterial richness. Conclusions Long-term whole broccoli supplementation decreased inflammation, improved lipid parameters, insulin sensitivity and altered the gut microbiome in mice. Our data provide new information regarding broccoli stalks' potential benefits in metabolic parameters.