BackgroundDysbiosis of gut microbiota and increased intestinal permeability are associated with various diseases, and their relationship with cognitive dysfunction such as cerebral small vessel disease (CSVD) and Alzheimer's disease remains to be elucidated.ObjectiveThis study investigates the role of gut microbiota dysbiosis and its relationship with intestinal permeability in patients with cognitive impairment associated with CSVD (CSVD-CI).MethodsIntestinal permeability was detected in 21 patients with CSVD-CI and 20 healthy controls by testing urine lactulose/mannitol, and correlation analysis was performed between the test results and cognitive function assessment. 16S rRNA sequencing was used to analyze the different combination of gut microbiota. Feces of the patients or controls were gavaged into C57 mice, and gut barrier function, behavior, and metabolites were assessed.ResultsPatients with CSVD-CI have a higher incidence of hypertension, higher homocysteine levels, higher scores for white matter hyperintensities, and worse cognitive function. Their urinary mannitol recovery rate is higher, which is correlated with lower scores of cognitive function assessment. Alterations in the gut microbiota involve a reduction in Prevotella-9 alongside increases in Proteobacteria and Fusobacteria. Fecal microbiota transplantation (FMT) from patients with CSVD-CI increases intestinal permeability in mice, but does not change their cognitive function; meanwhile, fecal metabolomics analysis has identified alterations in bile acids and vitamins, which are associated with shifts in the gut microbiota.ConclusionsPatients with CSVD-CI have gut microbiota imbalance and increased intestinal permeability, which are associated with cognitive decline. FMT from these patients can cause intestinal leakage and the production of harmful metabolites in mice.
Chen et al. (Fri,) studied this question.