Age-associated changes in intestinal health biomarkers in dogs

Abstract

The gut microbiome is critical for maintaining host health. In healthy humans, the aging process is one of the main factors modulating the changes in the intestinal microbiota. However, little is known about the relationship between gut health, microbiota, and the aging process in dogs. The present study aims to explore the differences in the intestinal microbiota and intestinal health based on fecal biomarkers in a population of dogs of different ages. The study involved 106 dogs of different breeds aged between 0.2 and 15 years categorized as senior (>7 years; n = 40), adult (2–7 years; n = 50), and junior (< 2 years; n = 16). Fecal samples were collected during the same period at the same facilities. The analysis included the following gut health indicators: 16S rRNA gene sequencing to investigate the differences in the fecal microbiota; qPCR to determine the dysbiosis index; fecal short-chain fatty acid concentrations; fecal calprotectin; and immunoglobulin A. Beta diversity analysis revealed a significant difference with a small effect size (p = 0.003; R = 0.087) among age categories based on the unweighted UniFrac metric, but no significance was observed based on the weighted UniFrac metric or Bray–Curtis distances. There were no significant differences in the alpha diversity measures or the fecal dysbiosis index among age categories. Senior dogs had significantly higher relative abundance proportions in phyla Bacteroidota and Pseudomonadota and the genus Faecalibacterium, but not on qPCR analysis. At the family level, Ruminococcaceae, Uncl. Clostridiales.1, Veillonellaceae, Prevotellaceae, Succinivibrionaceae, and Bacteroidaceae abundances were higher in the senior category than in the adult and/or junior categories. Relative proportions, but not concentrations of fecal acetate, were higher in the senior category, while butyrate, isovaleric acid, and valeric acid were lower. The valeric acid concentration was significantly lower in the senior category than in the adult category. Calprotectin and immunoglobulin A levels did not differ significantly across groups. In conclusion, this study observed multiple minor changes in the fecal microbiota composition and the relative amount of short-chain fatty acids in dogs among different age groups, but studies in larger populations representative of all ages are warranted to refine the present results.

Comparative analysis of the gut microbiota of the Chinese Kunming dog, German Shepherd, and Belgian Malinois

“…Previous studies have shown that age, sex, and physiological state are important factors affecting the intestinal ora of dogs [33]. For instance, among captive Beagle and Cocker Spaniel breeds, the abundance of Pseudomonas adaceae and Escherichia is signi cantly higher, while the abundance of Actinobacteria is signi cantly lower in the aged group (> 7 years) than in the adult group (2-7 years) [34]. The study on the intestinal ora of Maltese found that the abundance of Bacteroidota and Prehostella is signi cantly higher in females than in males, while the abundance of Atopobiaceae and Megamonas is signi cantly higher in males than in females and that there are signi cant differences in the beta diversities of the male and female individuals [35].…”

The Effects of Dietary Saccharomyces cerevisiae Supplementation on Gut Microbiota Composition and Gut Health in Aged Labrador Retrievers

“…Puppies have immature microbiota in the first few weeks of life, but by about 4–5 months of age, the gut flora become similar to those in adulthood and remain relatively stable until old age [ 7 ]. Aged dogs exhibit an increase in the abundance of Ruminococcaceae, Bacteroidaceae, Veillonellaceae, and Lachnospiraceae, accompanied by reduced production of valerate and butyrate [ 8 ]. In addition, the increased abundance of Bacteroidetes and its order Bacteroides, as well as the decreased abundance of Firmicutes and its genus Streptococcus, are associated with improved intestinal immunity in aged dogs [ 9 ].…”