Effect of diet on cognitive function and gut microbiota. (20th December 2022)

• Record Type: Journal Article
• Authors: Solch, Rebecca J; Engler‐Chiurazzi, Elizabeth; Harper, Colin; Wasson, Savannah; Ogbonna, Sharon; Ouvrier, Blake; McDonald, Katherine; Wang, Hanyun; Biose, Ifechukwude Joachim; Bix, Gregory J; Maraganore, Demetrius M
• Is Part Of: Alzheimer's & dementia. Volume 18(2022)Supplement 11
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-12-20
• Subjects: Alzheimer's disease -- Periodicals; Alzheimer Disease -- Periodicals; Dementia -- Periodicals; Démence; Maladie d'Alzheimer; Périodique électronique (Descripteur de forme); Ressource Internet (Descripteur de forme); 616.83
• DOI: 10.1002/alz.061639
• Languages: English
• ISSNs: 1552-5260

Abstract

Abstract: Background: Alterations in the gut microbiota have been observed in patients with mild cognitive impairment and Alzheimer's disease. Dietary consumption directly modulates gut microbiota; therefore, the quality of a diet may impact cognitive function and susceptibility to dementia. We hypothesized that consumption of the nutrient dense Mediterranean diet (MeDi) would improve cognitive function through beneficial changes to the gut microbiota as compared to the diet primarily consumed by Americans, the Western diet (WD). Method: Ten‐week‐old Sprague Dawley male rats were assigned a MeDi (n = 10) or WD (n = 9). After three months, Morris water maze (MWM) was used to assess spatial reference memory cognition. MWM data were analyzed with two‐way RM ANOVA. Fecal samples were collected prior to the MWM. Microbial composition was determined by 16S rRNA sequencing, and analyses included Mann‐Whitney with false discovery rate. Result: The MeDi group also spent significantly more time in the target quadrant during probe testing (p = 0.03) and was quicker to reach the platform on reversal testing (p = 0.004), indicative of improved cognitive flexibility. Microbiota α‐diversity indices, Shannon (p = 0.053), Simpson (p = 0.054), and Chao1 (p = 0.056), had a trend to be increased in the MeDi. Microbiota β‐diversity was dissimilar between diets (p<0.001). At the phylum level, Actinobacteria decreased and Patescibacteria increased with consumption of the MeDi as compared to the WD. Actinobacteria relative abundance correlated with MWM time in target quadrant (r = ‐0.58, p = 0.009). Further, relative abundance of Actinobacteria and Patescibacteria correlated with MWM reversal distance to reach platform (Actinobacteria, r = 0.77, p = 0.0001; Patescibacteria, r = ‐0.59, p = 0.007). Conclusion: The MeDi maintained long‐term spatial memory, as measured by the MWM, compared to the WD. Additionally, diet‐modulated gut microbiota at the phylum level and these changes were correlated with cognitive function. Modulation of the gut microbiota through a neuroprotective diet, such as the MeDi, may serve as a method to improve cognitive function.