Discussion
neurodegeneration, cognitive impairment, dementia, MCI, cognitive behaviors, Cognitive impairment
DEGENERATIVE, DISEASES, NEURODEGENERATION, SECONDARY
Recent studies have shown that gut microbiota plays an important role in degenerative diseases. However, no clinical trials of FMT for cognitive impairment have been reported. In this study, we found that FMT treatment could maintain stability or even alleviate cognitive impairment and change the structure of gut microbiota, metabolome, and metabolic pathways.Cognitive impairment is the main clinical manifestation of dementia (Previous studies have demonstrated that gut microbiota influences CNS function and metabolism through the gut-brain axis. Zhan et al. have suggested that different compositions of the gut microbiota might contribute to cognitive differences between senescence-accelerated mouse prone 8 (SAMP8) and senescence-accelerated mouse resistant 1 (SAMR1) mice. They have also found that pseudo-germ-free mice that received fecal bacterial transplantation from SAMR1 mice demonstrated improved cognitive behaviors, such as spatial learning and memory. At the same time, the intestinal diversity was increased, and the level of beneficial bacteria, such as According to our study, the differential metabolites mainly concentrated in bile secretion, choline metabolism, linolenic acid metabolism, phospholipid metabolism, and linoleic acid metabolism. Compounds secreted or affected by the gut microbiota lead to neurodegeneration through the blood-brain barrier (BBB). Recent evidence has shown that bile acids have protective and anti-inflammatory effects on the brain. Primary bile acids are decreased in AD and MCI patients, while secondary bile acids, such as taurodeoxycholic acid and deoxycholic acid produced by gut microbiota, are increased compared with normal controls (This experiment had certain limitations. First, the sample size was small. Second, there was a lack of a control group based on the results obtained through self-control before and after the treatment. Third, both gut microbiota and metabolites might be affected by region and dietary habits, limiting the generalizability of our findings.