| Objective:Studies have shown that the occurrence and development of stroke is closely related to intestinal flora,and the Rapid gut dysbiosis induced by stroke exacerbates brain infarction in turn.However,population-based studies have numerous confounding factors,and the dynamic effect of stroke on intestinal flora is not known exactly.Post-Stroke Cognitive Impairment(PSCI)is present in 40% of stroke survivors,and early diagnosis and treatment contribute to the recovery of cognitive function.However,the relationship between gut microbes and different levels of PSCI cognition remains largely unknown.Based on 16 s RNA and metabolomics,the present study explored the specific effects of stroke on intestinal flora and the material associations of the bacteria-gut-brain axis.Based on differences in cognitive function scores,differential microflora and differential metabolites related to cognitive function were explored to find possible diagnostic markers and potential treatment regimens.Methods:(1)Improving the Developed Photochemical Stroke Model(DPISM)to create more credible conditions for research;Healthy C57 mice were divided into 4 groups:1)Modified model group(group A),which were fed with intermittent high-fat diet for8 months,making a prerequisite of atherosclerosis,and then photochemical method was used to establish the focal infarction model;2)Conventional model group(Group B),photochemical modeling;3)High-fat diet control group(group C);4)Normal control group(group D),mice feces were collected at different timings before and after modeling(1 day before surgery and 1,3,7 days after surgery),and 16 s RNA high-throughput sequencing was used to detect intestinal flora at different time points before and after stroke,so as to clarify the specific changes after stroke.Based on the liquid mass spectrometry metabolomics,the changes of the metabolites in the ileoceca were analyzed,and the changes of the microenvironment in the brain were detected at the same time.The gut-brain covariant substances were analyzed to find the possible material basis of the bacteria-gut-brain axis.Based on the cognitive function score,the stroke model mice have been secondly grouping,and through bioinformatics analysis find out the significantly different bacteria and metabolites in mice of cognitive function differences.Using the material we found as dietary supplements fed mice,and proving in molecular biology experiments that the supplements has definite function.Results:We found that(1)The ? diversity of intestinal flora decreased at first and then increased after stroke modeling.the diversity of intestinal flora decreased for a period of time after stroke,especially on the first day after stroke,and increased on the third day.It gradually stabilized on the seventh day.(2)Stroke will affect the ? diversity and composition of intestinal flora,so that the difference of intestinal flora between different groups becomes smaller and tends to be similar.The effect of stroke on intestinal flora exceeded the difference between groups in different diets.The specific manifestation was that Bacteroidetes increased sharply within 3 days after operation and decreased after 7 days.The genera of Akkermansia,Alloprevotella,Prevotellaceae and Bacteroides all experienced the process of rising at first and then descending.The content of Bifidobacterium decreased on the first day after operation and recovered slightly on the seventh day.On the third day after operation,the Lactbacillus content was the lowest,and gradually recovered on the seventh day after operation.(3)Cerebral metabolites and intestinal microenvironment changed after stroke,with6986 positive ion peaks and 9765 negative ion peaks,involving a variety of lipids,oligopeptides and amino acids.Among them,there are 52 brain differential metabolites,30 intestinal differential metabolites and 52% same brain-intestinal differential metabolites.(4)Based on Spearman correlation analysis,237 pairs of microflora-metabolites with significant positive correlation and 234 pairs of microflora-metabolites with significant negative correlation were screened out.KEGG enrichment analysis showed that the differences were mainly concentrated in ABC transporter,protein digestion and absorption,and carbon metabolism in cancer signal pathway.(5)There were differences in the structure of bacteria in mice with cognitive differences.Mice with better cognition had more abundant Lactobacillus before stroke(P<0.05).The enteric-brain association analysis indicated that PC(16:0/16:0)thioetheramide-PC had the codirectional changes in the intestinal brain,and the ratio of thioetheramide-PC /PC(16:0/16:0)was negatively correlated with the cognitive level of Bifidobacterium,Allobacullum and Anaerofustis was positively correlated with phosphatidylcholine sialic acid dipeptide and other components.Among them,Bifidobacterium was highly correlated with PC(16:0/16:0)and its derivatives.This bacterium was commonly found in mice with better cognitive function,but not in most mice with poor cognitive function.PC(16:0/16:0)can stimulate the up-regulation of ABCB4 gene expression,reduce the ratio of secondary bile acid to primary bile acid,and reduce the content of ox-LDL 8-iso-PGF2? in brain tissue,so as to promote the recovery of cognitive function.Conclusions:(1)Stroke affected the composition of intestinal flora,which made the composition of intestinal flora of different groups tend to be consistent,and even exceeded the differences between groups caused by different diets,especially the changes of Bacteroides.(2)Brain metabolites and intestinal microenvironment changed after stroke.Common differential substances in intestine and brain accounted for 52% of brain differential metabolites,and they were all concentrated in ABC transporter,digestion and absorption of protein,and carbon metabolic signal pathway in cancer.(3)Lactococcus and Lactobacillus may be probiotics related to a variety of stroke differential metabolites.(4)PC(16:0/16:0)and Thioetheramide-PC may be the material bridge between intestine and brain.The ratio of PC/ Thioetheramide-PC was related to cognitive function.(5)Bifidobacterium was related to the difference in cognitive function of mice.(6)Supplementation of PC(16:0/16:0)can improve the cognitive function of mice after stroke. |
PDF Full Text Request