Aging Effects on Gut Microbiota in SAMP8 Mice

Abstract

We have studied the effects of aging on the fecal microbiota composition in the senescence-accelerated prone mice SAMP8 strain. We compared animals two, four, and six months old. Feces were collected at the end of each period and a genomic study was carried out on fecal DNA using the Illumina MiSeq analyzer. The Shannon diversity index showed similar values along this period and the number of species was neither affected by aging. The phylum Verrucobacteria went up with age, showing a seven-fold increase at six months, compared to two-month old mice. At the family level, changes observed between two and six months of age involved significant increases in Bacteroidaceae (q < 0.001) and strong reductions in Lactobacillaceae (q < 0.0001) and Prevotellaceae (q < 0.05); at the genus level, there was a significant reduction in probiotic Lactobacillus. At the species level, we observed an age-related reduction in Lactobacillus hayakitensis, a species involved in mucosal immune homeostasis, and in Blautia hansenii, which provides protection against Clostridium difficile infection. Interestingly, aging increases Parabacteroides goldsteiini, which is involved in the regulation of the TLR4 pathway. These results support the view that aging results in the proliferation of bacterial species that are associated with the immune deterioration of the gut mucosa.

Dietary Spray-Dried Porcine Plasma Reduces Neuropathological Alzheimer’s Disease Hallmarks in SAMP8 Mice

“…Changes in the composition of the gut microbiota coextensive with aging likely contribute to immunosenescence and to the development of a pro-inflammatory phenotype [ 69 ]. In fact, SAMP8 mice at 6 months of age, showed a reduction in probiotic species, while the proinflammatory species of the intestinal microbiota increased [ 70 ]; these are able to secrete bacterial amyloids and lipopolysaccharides that are considered neurotoxic [ 71 ]. Moreover, SDP increases the presence of bacterial families that enhance the intestinal barrier function, as well as the growth of species that are well-known mediators of anti-inflammatory and tolerogenic responses [ 23 , 72 ].…”

Spray-Dried Animal Plasma as a Multifaceted Ingredient in Pet Food

“…In addition, the neuronal protective effects of SDAP were attributed to its effects on the gut in two other publications [5,83] by this same research group, which demonstrated that aging in mice induces mild-grade inflammatory changes and that senescence promotes an increase in populations of potentially pathogenic microorganisms, with a reduction in microorganisms with probiotic potential (Lactobacillus hayakitensis and Blautia hansenii) that promote protection against infections by Clostridium spp. In this study [83], supplementation of SDAP reversed such deleterious changes in the aging animals, promoting an effective response to an intestinal challenge.…”