Attenuation of metabolic syndrome in ob/ob mice model by resistant starch intervention is dose dependent
The current study applied an ob/ob mice model of obesity for investigating the impact of different RS does in high-fat (HF) diet on the attenuation of metabolic syndrome. Although a significant reduction of the body weight was not achieved, RS intervention significantly decreased liver weight with suppressed lipids accumulation in the liver tissue and a reduced adipocyte size in the fat tissue. All levels of RS intervention were associated with a significantly enriched pathways for PPAR signaling, NAFLD and cGMP-PKG signaling. In contrast, either a medium or a higher RS intake (MRS and HRS, respectively) led to AMPK signaling pathway to be significantly enriched but not a lower RS-containing diet. More importantly, sphingolipid biosynthesis activity was noted with MRS and HRS intervention, which is highly associated with the improvement in insulin resistance, and the pathway of type II diabetes mellitus was corresponding significantly enriched in HRS group, demonstrating a dose-dependent manner. Similarly, there was no significant difference in the ratio of Bacteroidetes and Firmicutes between high-fat diet and RS group until RS reached certain level (i.e. in HRS group). Furthermore, an increased profiles of both Prevotellaceae and Coriobacteriaceae in the HF group were firstly noted with a revised function from RS intervention, which is consistent with content of lipopolysaccharides in their corresponding serum. Gut microbiota functional analysis showed that primary and secondary bile acid biosynthesis was also noted to be enriched following the RS intervention, benefiting the cholesterol homeostatasis. This study further highlights that RS in dietary intervention is characterized by a dose-regulatory manner, contributing to design of future functional foods for treatment of obesity.