High levels of dietary digestible protein transiently promote beneficial bacteria in adult dog feces

Nowadays, many commercial dog diets select the ingredients not only to meet the needs of the individual and maintain a balance between nutrition/microbiome/health; fiber and protein quality is known to be one of the most important factors in this balance. Diets high in low digestible protein tend to favor microorganisms that when fermenting amino acids generate substances that induce inflammation, while high digestible protein and fermentable fibers have been related to beneficial bacteria. The study's objective was to identify changes in the relative abundance of specific microorganisms (Clostridium perfringens, Enterococcus faecium, Lactobacillus salivarius, Bacteroides fragilis and Fusobacterium varium) by PCR (polymerase chain reaction), associated with two diets of different quality and digestibility. Twenty adult dogs were used, divided into two groups, the first one fed with a high digestibility diet (HD) (n = 10), the second one with a low digestibility diet (LD) (n = 10). After 3 days of adaptation to the diet, fecal samples were taken at days 15 and 30. The results showed that the high-quality diet promotes a transient increase (15 days) in the relative abundance of F. varium and E. faecium, as well as a persistent increase in that of L. salivarius and B. fragilis until day 30. Apparently, however, healthy adult dogs eventually balance their fecal microbiota, regardless of the dietary protein level and digestibility. Therefore, it is difficult to identify clear patterns of the ideal dietary profile in this species.