Changes in Gut Inflammation and Microbiome Linked to Thinking Abilities Revealed by Blood and Stool Analysis

Alpha diversity of gut microbiota decreased with increasing cognitive impairment severity.

• Short-chain fatty acid-producing Firmicutes and Bacteroidota decreased from 76% and 17% in healthy controls to 59% and 11% in dementia, respectively.
• Proteobacteria levels rose from less than 2% to 4%, and Verrucomicrobiota increased from 3% to 11% in dementia.
• Ruminococcus gnavus, a mucus-degrading species, increased despite the overall decline in Firmicutes.
• Elevated plasma cytokines were correlated with changes in gut microbiota, indicating a potential link between gut dysbiosis and systemic inflammation.
• Alterations in bacteria-associated metabolites, including bile acids and fatty acids, were significantly observed and could serve as early biomarkers.

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