ABSTRACT
Objective To investigate the gut microbial characteristics and risk factors in people with mild cognitive impairment. Methods Twenty-eight people with mild cognitive impairment and 65 age-, gender- as well as education-matched controls were recruited. Carotid artery ultrasonography was conducted and fasting anticoagulant blood and fresh fecal samples were collected on all subjects. Total bacterial DNA was extracted from the stool samples and amplified through real-time quantitative polymerase chain reaction (qPCR). Next generation analysis of 16S rRNA was performed to achieve genomic sequences using the Illumina Hiseq 2500 platform. Results Compared with the control group, mild cognitive impairment group exhibited greater microbial diversity (Bray Curtis distance, Adonis test, P<0.05), which were characterized by enrichment of proteobacteria, Synergistetes, lactobacillus, and depletion of Epulopiscium. Age, creatinine, average CCAIMT, Crouse score, and plaque numbers were associated with cognitive impairment. Multiple logistic regression analysis revealed that the number of hyperechoic plaques (OR=11.511, 95%CI:1.406~94.226, P=0.023) and the abundance of lactobacillus (OR=4.894, 95%CI: 1.090~21.966, P=0.038) were the important risk factors for mild cognitive impairment. Conclusion Higher abundance of lactobacillus in the gut holds potential as novel risk factor of people with mild cognitive impairment.
ABSTRACT
Objective To investigate the gut microbial characteristics in patients with acute ischemic stroke and resilience of the gut microbiota after a stroke. Methods Ninety-five fecal samples from 28 ischemic stroke patients and 28 fecal samples from 28 healthy volunteers were collected.DNA was extracted from these samples and the bacterial 16S rRNA were amplified through real-time quantitative polymerase chain reaction (qPCR). All PCR products were mixed together and then sequenced using the Illumina Hiseq 2500 platform. Microbiome analysis was implemented in QIIME. Results Patients with acute ischemic stroke showed significantly higher diversity than controls (phylogenetic diversity, P=0.002). The overall composition of the gut microbial communities also differed significantly between acute ischemic stroke patients and healthy controls as indicated by the clear separation in principle coordinate analysis (Adonis test on Bray-Curtis, P<0.001). Stroke patients' intestines had more opportunistic pathogens, such as Enterobacteriaceae, Veillonellaceae and Streptococcaceae, fewer commensal or beneficial genera including Bacteroides and Prevotella. Four weeks after onset, the gut microbiota in stroke patients began to restore, but the alpha diversity declined (P<0.05). Conclusion The present study has revealed the characteristic of gut microbial dysbiosis and recovery in acute ischemic stroke patients.However,the significance of the dynamic gut microbiota in stroke patients needs further study.