Supplementation of a new combination of prebiotic and postbiotic shapes fecal microbiota of old dogs while influencing immune parameters

Abstract

Healthy senior dogs were subjected for 77 days to a dietary regime with (or without) prebiotic + postbiotic mixture composed by short-chain fructo-oligosaccharides and yeast fractions (scFOS+). Their fecal microbiota was studied and the links between the microbiota and immune parameters were investigated after Lyme vaccination. All along the study results showed a clear modulation of the microbiota with a higher relative abundance (RA) for Megamonas spp., Bacteroidaceae, Bacteroidetes plebeius, Clostridiales, Phascolarctobacterium, Succinivibrionaceae, Fusobacterium spp. in feces from scFOS + dogs. An amplicon sequence variants (ASVs) index (Enterobacteriaceae + Clostridium spiroforme vs. Fusobacterium + Megamonas) was developed and found significantly different between the groups with scFOS + dogs showing a lower index suggesting a possible modulation of the physico-chemical environment in the gut, favoring the growth of strict anaerobes producing short-chain fatty acids. Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt2) analysis revealed stimulation of propionate and acetate production pathways, vitamin biosynthesis (vitamin B2, B5 and B9 precursors) and pathways related to tricarboxylic acid cycle in the scFOS + group. The RA of several ASVs from Bacteroidetes and Fusobacteria families were found moderately negatively correlated to IgA and IgG concentrations (P < 0.05). In particular, Megamonas and Phascolarctobacterium appeared as interest genera. In summary, scFOS + is a good candidate to support the health of elderly dogs through microbiota changes. Metabolomics or in vitro mechanistic experiments will be crucial to further understand the mechanisms at play.

Keywords: Dog; Elderly; Immunosenescence; Microbiota; Postbiotic; Prebiotic.

Fig. 1

Experimental design of the trial, adapted from Wambacq et al. (2024). 16 dogs were included after passing a health screening (blood, urine and lyme antibody test) and other inclusion criteria, and were dewormed 3 days before day 0. From day 4 to day 7 dogs per group were adapted to the experimental diet (Ccontrol or scFOS+) for 3 weeks until lyme vaccination at day 28 (collecting fecal and blood samples right before), then booster vaccination at day 49. The final fecal and blood samples were collected at day 77.

Fig. 2

Relative abundance (%) of the phylum in Control and scFOS + at D28 and D77. Asterisk (*) represents significant higher relative abundance at phyla level at D77 between treatments using ANCOM analysis (P < 0.05).

Fig. 3

Non-metric multidimensional scaling (NMDS) of unweighted Unifrac distances betweenCcontrol and scFOS + during the experiment. Ellipses show 1.5 SD at D77 (P < 0.05) (A). Principal component analysis (PCA) of Aitchison distances of the treatments per time point with weight of the discriminant ASVs represented by arrows length from DEICODE. Data points represent individual samples and vectors are taxa driving differences in ordination space (B).

Fig. 4

Ratio of taxonomic differences between Control and scFOS+. Ranking of principal component analysis (PCA) Axis 1 taxonomic loadings highlighting the 2 highest features loading amplicon sequence variants (ASVs) (A). Box plots of natural log ratios (Enterobacteriaceae + C. spiroforme)/(Megamonas spp.+Fusobacterium spp.) and (C. spiroforme/Fusobacterium spp.) per treatment time points (B) and significant correlated with PCA Axis 1 (ρ: Spearman correlation coefficient) (C). Horizontal bar with * shows significant differences between treatments (including both D28 and D77) and at D77 (P < 0.05).

Fig. 5

Absolute abundance of significant different MetaCyc pathway classes found between treatments (including both D28 and D77) with PICRUSt2 (P < 0.05) using ALDEx2 analysis. Results are mean ± standard error.