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.

Humans ; Brain-Computer Interfaces ; Consciousness Disorders ; Consciousness ; Electroencephalography ; Brain