Relation of fecal microbiome with the source of starch in free ranging dogs housed in a shelter.

The intestinal enzymatic feature of the modern breeds of dogs can digest starch and, accordingly, variable amounts of starchy foods can be included in the diets. Potato and rice contain a different type of starch and a dietary intervention study was conducted in dog to evaluate the variations of faecal microbiome in relation to the source of starch in home made diets.Thirty adult dogs housed in a shelter were selected and fed a diet based on a mixture of rice, pasta and fresh raw meat. For the study, a group of dogs continued to receive this diet (CD), a second group (B1) was assigned to a diet with rice as main source of starch (CB1), and the third group (B2) was fed with a diet containing potato instead of rice. Samples of faeces were collected from each dog before the morning meal at the beginning (T0) and after 15 days (T15) and analyzed for pH, ammonia N (N-NH3) and total N (TN), short chain fatty acids (SCFA) and lactic acid. Relative abundance (RA) of faecal microbiota was assessed by sequencing and annotating the V3-V4 regions of the 16S rRNA.The total amounts of starch of the diets was similar, but starch differed for in vitro rate digestion and the undigestible starch was higher in B2 than B1 and CD diets. Dog fed B2 diet (potato starch) showed lower (PThese results suggest that small changes of diet composition, providing comparable supply of nutrients, have limited effects on faecal microbiome in in healthy dogs. Furthermore, the data obtained underline the high individual variability of microbiota among dogs.