The specific hydrolysis process of the patented Saccharomyces yeast hydrolysate Progut® transforms the yeast cell wall molecules into bioactive form. This makes Progut® a versatile product and it has previously been shown to improve the performance of chicken, pigs, calves, dairy cows, sheep and fish. A recent article by Strompfova et al. 2021 reports its potential benefits in dogs. 

The intestinal homeostasis of dogs is often challenged by a variety of stressors. Change in diet, bacterial or parasite infections, dietary indiscretion or stress can cause intestinal disturbances. Diverse, healthy and stable microbiota can help to maintain the intestinal balance under different challenges. Yeast products have shown to modulate immunity and intestinal microbiota and thus to reduce intestinal disturbances in different animal species. However, scientific data on the effects of yeast products in dogs is scarce.   

The main aims of the study were to determine the effect of Saccharomyces yeast hydrolysate supplementation on microbiological, immunological and hematological parameters in adult, healthy dogs. 20 adult German shepherd dogs were randomly divided into control and experimental group supplemented with Progut® yeast hydrolysate.  The dogs were in good physical condition without any clinical signs of diseases and had an average bodyweight of 31.5 kg.

All the dogs were fed with a commercial dry dog food and the dogs in the experimental group received additionally the yeast hydrolysate supplementation of 3 grams/kg daily during the feeding times. The yeast hydrolysate supplementation lasted for two weeks and its effect on the studied parameters was monitored until 42 days. Fresh fecal samples were collected in air-tight containers at days 0, 14, 28 and 42 and the microbial populations were analyzed by plate counting using selective medias for different bacteria. Blood samples were collected at days 0, 14, 28 and 42 for hematological and immunological analyses.

The yeast hydrolysate Progut® supplementation to dogs for 14 days resulted in significant changes of several tested bacterial genera, mostly during the post-treatment period (Table 1). The most meaningful change was observed in the numbers of fecal Bifidobacterium sp. which increased already at D14 and remained higher at D42 compared with the initial values. The abundance of lactic acid bacteria and Clostridium sp. were higher than the initial values at D42 in the experimental group but not at the other time points. Populations of coliform bacteria, Pseudomonas sp., and Staphylococcus sp. were not affected by the yeast hydrolysate supplementation. Different Bifidobacterium strains may have beneficial effects in the gut by reducing the colonization of pathogenic bacteria and modulating immune responses. Canine-derived Bifidobacterium strain have shown to reduce diarrhea in dogs (Kelley et al. 2009). Fecal score was optimal in both treatments throughout the study and fecal dry matter did not differ between the treatments.

The measured hematological and immunological parameters were not affected by the application of yeast hydrolysate (data not shown). The data of this study suggested that feeding yeast hydrolysate Progut to dogs may have positive effects on the microbiota of dogs. Further studies at different doses are needed for verifying the effects.

Table 1. Fecal microbiological populations (log CFU/g)

a, b: different letters indicate significant differences (P < 0.05) over time in the same group