Water extract of Goji berries improves neuroinflammation induced by high-fat high-fructose diet based on bile acid-mediated gut-brain axis pathway

Water extract of Goji berries improves neuroinflammation induced by high-fat high-fructose diet based on bile acid-mediated gut-brain axis pathwayThe high-fat and high-fructose diet (HFFD) is a common diet in Westernized societies, which worsens disturbances in gut microbiota and bile acid (BA) metabolism. Herein, this study aimed to investigate the effect of the water extract of Lycium barbarum fruits (LBE) on gut mcirobiota and BA metabolism in HFFD-induced neuroinflammation mice. Herein, it was found that the supplementation of LBE for 14 weeks remarkably ameliorated weight gain and insulin resistance, suppressed microglia activation and neural neuroinflammation induced by HFFD. The results of Morris water maze and Y maze tests demonstrated that LBE attenuated HFFD-induced cognitive impairment. Moreover, LBE elevated hepatic BAs biosynthesis and excretion of BAs and enriched the removal by fecal loss. Notably, LBE supplementation resulted in the enrichment of tauroursodeoxycholic acid (TUDCA) in cortex and hippocampus. Furthermore, the 16S rDNA results illustrated that LBE could modulate the structure of gut microbiota and meanwhile decrease the relative abundance of Clostridium_XlVa, which is associated with BAs homeostasis. Additionally, LBE exerted neuroprotective effects involving the increment of Lactococcus, potentially beneficial bacterium. These results demonstrated that LBE could ameliorate neuroinflammation and cognitive impairment in HFFD-induced mice through the gut-liver-brain axis, which might be due to the regulation of BAs homeostasis and gut microbiota in mice.