Maternal shaping of puppies' faecal microbiota

Little is known about the dam's role in shaping her puppies' faecal microbiota [1,2]. The aim of this study was to asses the eubiotic faecal microbiota of puppies from birth to around-weaning, and to evaluate the maternal influence on it using a metagenomic approach. Four dams of two medium-sized breeds, housed in the same ken- nel, and their litters (21 puppies), born naturally after healthy preg- nancies were studied. Colostrum (day 0, 2), vaginal (0, 2), and rectal (0, 2, 30) samples were collected from the dams (N = 28 samples), and rectal samples from the puppies, at the 3-time points (N = 63 samples). Ambient air samples (day 0) served as controls. The mi- crobiota was analysed by 16S rRNA sequencing and nucleic acids were extracted from samples using an RNeasy Power Microbiome kit (Qiagen). Illumina libraries were prepared and data were ana- lysed with Qiime2 (standard pipeline) and R (cluster analysis). The results of taxonomic identification were examined (Silva database). The distribution of patterns showed a very heterogeneous situation. Jaccard distance plot revealed a fairly clear separation according to the time of collection. On day 2, the rectal microbiota of the puppies shows a characteristic pattern with no similarity to other collection sites and times (beta diversity permanova q value <0.05). On day 30, it is similar to the dams' rectal microbiota (beta diversity permanova q value >0.05). The ambient air samples were significantly different from all the samples except that of the puppies' at day 0. A strong maternal effect was observed, as a dam and her litter showed more similarity than different dam-litter units, confirming previous results using cultural methods [2]. [1] Garrigues, Front Vet Sci. 2022;9:964649. [2] Del Carro, BMC Vet Res, 2022;18(1).