On the Role of Intestinal Microbiota in Patients with Cognitive Decline

Objective： The association between gut microbiota composition and biomarkers of immune activation and inflammation was assessed in the elderly. Patients： Serum inflammation markers of fifty-five outpatients （29 females, 26 males, aged 78 ＋ 8.5 years） were analyzed. Stool specimens and thus data on gut microbiota were available from a subgroup of 23 individuals （9 females and 14 males）. Results： Global cerebral atrophy was found in all magnet resonance tomography scans. Mean mini-mental-score examination in Alzheimer＇s disease patients was 18.8 ± 7.1, in patients with mild cognitive impairment 27.8 ± 1.5. Serum neopterin concentrations correlated with concentrations of fecal S100A12 （p 〈 0.001） and cq-antitrypsin （p 〈 0.05）. Faecalibacterium prausnitzii correlated with MMSE （p 〈 0.05）, with Akkermansia muciniphila （p 〈 0.01） and with serum neopterin （p 〈 0.05）. Fecal zonulin correlated inversely with Clostridium cluster I （p 〈 0.02）. Conclusions： Our results underline earlier in vitro and animal studies that cognitive decline associates with age-related changes in the intestinal microbiota and neuroinflammation. However, only correlational evidence can be reported, and a causative relationship still has to be demonstrated.