Broccoli Florets Supplementation Improves Insulin Sensitivity and Alters Gut Microbiome Population—A Steatosis Mice Model Induced by High-Fat Diet

Abstract

Nonalcoholic fatty liver disease (NAFLD) is linked to obesity, type 2 diabetes, hyperlipidemia, and gut dysbiosis. Gut microbiota profoundly affects the host energy homeostasis, which, in turn, is affected by a high-fat diet (HFD) through the liver-gut axis, among others. Broccoli contains beneficial bioactive compounds and may protect against several diseases. This study aimed to determine the effects of broccoli supplementation to an HFD on metabolic parameters and gut microbiome in mice. Male (7–8 weeks old) C57BL/J6 mice were divided into four groups: normal diet (ND), high-fat diet (HFD), high-fat diet+10% broccoli florets (HFD + F), and high-fat diet + 10% broccoli stalks (HFD + S). Liver histology and serum biochemical factors were evaluated. Alterations in protein and gene expression of the key players in lipid and carbohydrate metabolism as well as in gut microbiota alterations were also investigated. Broccoli florets addition to the HFD significantly reduced serum insulin levels, HOMA-IR index, and upregulated adiponectin receptor expression. Conversely, no significant difference was found in the group supplemented with broccoli stalks. Both broccoli stalks and florets did not affect fat accumulation, carbohydrate, or lipid metabolism-related parameters. Modifications in diversity and in microbial structure of proteobacteria strains, Akermansia muciniphila and Mucispirillum schaedleri were observed in the broccoli-supplemented HFD-fed mice. The present study suggests that dietary broccoli alters parameters related to insulin sensitivity and modulates the intestinal environment. More studies are needed to confirm the results of this study and to investigate the mechanisms underlying these beneficial effects.

Beneficial Effects of Broccoli (Brassica oleraceavaritalica) By-products in Diet-induced Obese Mice

“…Diet-induced obese mice can develop liver fatty changes, a condition also referred to as hepatic steatosis, that can be alleviated by broccoli, glucoraphanin or broccoli microgreens juice supplementation (22,34,36,37,39). However, another study using broccoli florets or stalks in diet-induced obese mice reported no changes in hepatic steatosis (38). In our study, the WD group showed mostly diffuse liver fatty changes, which was significantly different from the CTR group.…”

“…Moreover, the oral administration of broccoli microgreens juice, at a dose of 20 g/kg/day, reduced body weight, white fat mass and liver fat in HFD-fed mice (37). Conversely, the ingestion of broccoli florets (10%) or stalks (10%) for 17 weeks, by mice fed with HFD did not affect final body weight, fat accumulation or liver weight (38). In another study, for mice fed a Western diet with 10% broccoli powder (equivalent to 0.4 mmol glucoraphanin/kg diet) for 31 weeks, the final body weight was not affected by broccoli supplementation (39).…”

Metabolic and Microbiome Alterations Following the Enrichment of a High-Fat Diet With High Oleic Acid Peanuts Versus the Traditional Peanuts Cultivar in Mice

“…On the 16th week, an oral glucose tolerance test (OGTT) was performed in overnight (12 h) fasted mice as previously described ( 14 ).…”

“…#EZRMI–13K). Homeostatic model assessment for insulin resistance (HOMA-IR) index was calculated as previously described ( 14 ). Plasma FFA was determined using an Abcam Free Fatty Acids Quantification Assay Kit (ab65341) according to the manufacturer’s instructions.…”

Cannabis Extract Effects on Metabolic Parameters and Gut Microbiota Composition in a Mice Model of NAFLD and Obesity

“…Liver tissue lysates were prepared using lysis buffer as previously described [ 23 ]. Aliquots of protein were then subjected to western blot analysis.…”