Young versus aged microbiota transplants to germ-free mice: increased short-chain fatty acids and improved cognitive performance

• Published in: Gut microbes 2020-11, Vol.12 (1), p.1-14
• Main Authors: Lee, Juneyoung, Venna, Venugopal R., Durgan, David J., Shi, Huanan, Hudobenko, Jacob, Putluri, Nagireddy, Petrosino, Joseph, McCullough, Louise D., Bryan, Robert M.
• Format: Article
• Language: English
• Subjects: acetate; Aging; butyrate; cognitive decline; germ-free mice; gut microbiome; inflammation; propionate; short-chain fatty acids
• ISSN: 1949-0976; 1949-0984
• DOI: 10.1080/19490976.2020.1814107

Aging is associated with cognitive decline and decreased concentrations of short-chain fatty acids (SCFAs) in the gut. SCFAs are significant in that they are protective to the gut and other organs. We tested the hypothesis that the aged gut microbiome alone is sufficient to decrease SCFAs in the host and produce cognitive decline. Fecal transplant gavages (FTGs) from aged (18-20 months) or young (2-3 months) male C57BL/6 mice into germ-free male C57BL/6 mice (N = 11 per group) were initiated at ~3 months of age. Fecal samples were collected and behavioral testing was performed over the study period. Bacterial community structures and relative abundances were measured in fecal samples by sequencing the bacterial 16S ribosomal RNA gene. Mice with aged and young microbiomes showed clear differences in bacterial β diversity at 30, 60, and 90 d (P = .001 for each) after FTGs. The fecal SCFAs, acetate, propionate, and butyrate (microbiome effect, P