Blood test using gut health signals may predict cognitive decline years earlier

A University of East Anglia study analyzed blood and stool from 150 adults aged 50+ and identified 33 gut‑microbe metabolites; an AI model using six metabolites classified healthy, mild cognitive impairment (MCI), and subjective cognitive impairment (SCI) groups with about 79% overall accuracy and over 80% for healthy versus MCI.

Researchers have developed the basis for a blood test that uses gut microbiome signals to help identify early cognitive decline. The University of East Anglia team published the work in the journal Gut Microbes. The study analyzed blood and stool samples from 150 adults aged 50 and older, including people with no impairment, mild cognitive impairment (MCI), and subjective cognitive impairment (SCI). The research examines microbe‑derived metabolites that enter the bloodstream and could reflect interactions along the microbiota‑gut‑brain axis. Key findings: - The study included 150 adults aged 50 and over across three groups: no cognitive impairment, mild cognitive impairment (MCI), and subjective cognitive impairment (SCI). - Researchers identified 33 microbe‑derived metabolites from blood and stool samples and analyzed combinations of these chemicals. - An AI‑powered model using six of the discovered metabolites classified participants into the three study groups with about 79% accuracy and distinguished healthy adults from those with MCI with over 80% accuracy. - The authors reported changes in gut bacteria and circulating metabolites even among participants with only mild memory changes. - Clinicians quoted in the report described the microbiota‑gut‑brain axis as a plausible pathway and emphasized that larger, more diverse, and longitudinal studies are needed, plus direct comparison with established Alzheimer's blood biomarkers. Summary: The study presents early evidence that gut‑derived metabolites measured in blood might help distinguish early cognitive changes, but the results are preliminary. Researchers and outside clinicians said replication in larger and more diverse cohorts tracked over time is needed, along with comparison to established Alzheimer's biomarkers. Further investigation into whether targeting diet, metabolism, or the gut microbiome affects cognitive outcomes was also noted as a next research step.