Potential Effects of Alpha-Glycosyl Isoquercitrin on Memory by Altering the Gut Microbiota-Blood-Brain Axis in Mice

Changes in Microbial Ecosystems and Serum Metabolomics by Diet Supplementation With Enramycin in Weaning Piglets

Antibiotics are used in swine production for growth promotion and disease prevention, raising concerns about environmental contamination and antibiotic resistance. In this study, we investigated the effects of enramycin supplementation on piglet growth, gut microbiota and blood metabolites. Enramycin promotes piglet growth and temporarily reduces diarrhoea. Gut microbiota analysis revealed changes in microbial composition, including an increase in the abundance of Limosilactobacillus reuteri. Metabolomic analysis has identified elevated levels of dimethylglycine, a known growth-promoting factor, in the enramycin group. Liver gene expression analysis revealed increased mRNA levels of ALDH and dimethylglycine dehydrogenase, which are enzymes involved in dimethylglycine metabolism. The enramycin-treated group had a higher concentration of acetic acid in caecal contents, and their caecal acetic acid concentrations were positively correlated with the abundance of L. reuteri and the content of serum dimethylglycine, respectively. These findings suggest that the promotion effect of enramycin on piglet growth is related to the gut microbiota, blood metabolites and liver gene expression, which provide insights into antibiotic alternatives for swine production.

Alpha-glycosyl isoquercitrin alleviates subchronic social defeat stress-induced depression symptoms by modulating the microbiota-gut-brain axis in mice

AIMS

Increasing evidence suggests a link between gut microbial dysbiosis and the pathogenesis of depression. Alpha-glycosyl isoquercitrin (AGIQ), consisting of isoquercitrin and its glycosylated quercetin, has beneficial effects on the gut microbiome and brain function. Here, we detected the potential antidepressant impact of a four-week administration of AGIQ and its underlying mechanisms using a mouse model of depression.

MAIN METHODS

Male C57BL/6 mice were orally administered AGIQ (0.05 % or 0.5 % in drinking water) for 28 days; subchronic social defeat stress was performed in the last 10 days. Behavior tests were conducted to assess anxiety and depressive-like behaviors. Additionally, evaluations encompassed 5-hydroxytryptamine (5-HT) levels, the gut microbiota composition, lipopolysaccharide (LPS) concentrations, short-chain fatty acids levels, and intestinal barrier integrity changes.

KEY FINDINGS

AGIQ significantly alleviated depression-like behaviors and increased hippocampal 5-HT levels. Further, AGIQ mitigated stress-induced gut microbial abnormalities and reduced the levels of LPS in the serum, which affected the relative gene expression levels of 5-HT biosynthesis enzymes in vitro. Furthermore, AGIQ reversed the reduced butyrate levels in cecal contents and improved the impaired intestinal barrier by increasing the expression of colonic zonula occluden-1 (ZO-1) and occludin, thereby decreasing LPS leakage.

SIGNIFICANCE

Our results suggest that AGIQ could improve stress-induced depression by regulating the gut microbiome, which inhibits LPS production and maintains the gut barrier. This is the first report on the potential effect of AGIQ on depression via the gut microbiota-brain axis, shedding new light on treatment options.