A126: High-Intensity Interval Training and Medium-Intensity ContinuousMay Affect Cognitive Function Through the Microbiota-Gut-Brain Axis

Background/Purpose: The gut-brain axis is the communication mechanism between the gut and the central nervous system, and the intestinal flora and lipopolysaccharide (LPS) play a crucial role in this mechanism. Exercise regulates the gut microbiota composition and metabolite (i.e., LPS) production. We aimed to investigate the effects of moderate-intensity continuous training and high-intensity interval training (HIIT) on cognitive function in C57BL/6J mice through gut-brain axis regulation of gut microbiota composition and LPS displacement. Method: C57BL/6J male mice were randomly assigned into a quiet group (WTC), a high-intensity interval training group (WTH) and a moderate-intensity continuous training group (WTE). After 12 weeks of exercise intervention, the cognitive function of the brain and the mRNA levels of related inflammatory factors were detected, and RNA sequencing, Golgi staining, intestinal microbial 16s rDNA sequencing and ELISA Assay were performed. All information was analyzed with IBM SPSS Statistics 26 and GraphPad Prism 9.0. Mean ± standard error of the mean (SEM) was used to represent MWM findings. Standard deviation ± mean (mean ± SD) is used to express other data. With P < 0.05 denoting statistical significance, post hoc multiple comparisons were performed using the least significant difference method and one-way ANOVA tests. Results: The results showed that MICT increased ZO-1 mRNA and Syn mRNA expression (p < 0.05), and increased dendritic spine density in the brain of mice (p < 0.05). However, HIIT increased the LPS content (p < 0.05), the expression of inflammation-related genes (CD86 mRNA, TLR4 mRNA and HK2 mRNA, etc, p < 0.05), and the ratio of Firmicutes/Bacteroidetes at the phylum level and decreased the density of dendritic spines in the blood and brain of C57BL/6J mice (p < 0.05). Conclusion: In conclusion, HIIT and MICT affect brain cognitive function by regulating the composition of gut microbiota and its metabolite LPS through the gut microbiota-gut-brain axis, and HIIT was suspected to have certain risks: It can induce "intestinal leakage" by regulating intestinal permeability related microbiota, resulting in excessive LPS into the blood and brain, and activate M1 microglia in the brain, leading to reduced dendritic spine density and affecting cognitive function.