Yeast Saccharomyces and its derivatives have been largely used in livestock and poultry nutrition for their potential positive impact on growth, performance, and general health. Originally included in animal diets as a source of protein, yeasts can also offer a wide range of by-products with interesting bioactive compounds that would confer uses beyond nutrition. Although its supplementation in livestock, poultry and even in humans is well documented, the available body of literature on the use of yeast and its derivatives in companion animals’ food, mainly dogs and cats’ diets, is still developing. Despite this, gut microbiota modulation, immune system enhancement or decreasing of potentially pathogenic microorganisms have been reported in pets when using these products, highlighting their possible role as probiotics, prebiotics, and postbiotics. This review attempts to provide the reader with a comprehensive on the effects of Saccharomyces and its derivatives in pets and the possible mechanisms that confer their functional properties.

The aim was to evaluate the effects of yeast probiotic on diet digestibility, fermentative metabolites, and fecal microbiota of dogs submitted to dietary change. Sixteen dogs were divided into two groups of eight dogs each: control, without, and with probiotic, receiving 0.12 g/dog/day of live Saccharomyces cerevisiae yeast. The dogs were fed a lower protein and fiber diet for 21 days and then changed to a higher protein and fiber diet until day 49. Yeast supplementation did not statistically influence diet digestibility. The probiotic group had a lower fecal concentration of total biogenic amines (days 21 and 49), ammonia (day 23), and aromatic compounds and a higher fecal concentration of butyrate (p < 0.05). The probiotic group showed a lower dysbiosis index, a higher abundance (p < 0.05) of Bifidobacterium (days 35 and 49) and Turicibacter, and a lower abundance of Lactobacillus and E. coli (p < 0.05). Beta diversity demonstrated a clear differentiation in the gut microbiota between the control and probiotic groups on day 49. The control group showed upregulation in genes related to virulence factors, antibiotic resistance, and osmotic stress. The results indicated that the live yeast evaluated can have beneficial effects on intestinal functionality of dogs.

Periodontal disease (PD) is one of the most widespread oral inflammatory diseases in dogs, with the potential to cause systemic consequences. The purpose of this study was to evaluate the inhibitory potential of yeast-derived postbiotics and probiotic bacterial strains by using a previously developed in vitro biofilm model mimicking canine PD-associated biofilm including five bacterial species: Neisseria zoodegmatis, Corynebacterium canis, Porphyromonas cangingivalis, Peptostreptococcus canis, and Enterococcus faecalis. After we confirmed the presence of these five bacterial species by employing Fluorescence In Situ Hybridization, the biofilm inhibitory and eradication activity of 11 yeast-derived postbiotics and probiotic bacterial strains, as well as selected dual biotic combinations, against the polymicrobial biofilm were determined using a modified version of the Calgary Biofilm Pin Lid Device and the crystal violet method; additionally, hemolytic activity was evaluated using canine red blood cells. The results show that the inhibitory activity against the polymicrobial PD biofilm ranged from 0% to 22.55%, and eradication ability varied between 0% and 17.28%; however, when combined, the biotics achieved a maximum inhibition rate of 71%. Probiotic strain BC-05 exhibited the lowest in vitro hemolytic activity. Overall, based on the results, four yeast-derived postbiotics and one probiotic bacterial strain were selected as promising candidates for further evaluation, aiming at in vivo application.

In dogs, gut microbiome dysbiosis is associated with several health conditions, including gastrointestinal disease. Probiotic supplementation can support a balanced gut microbiome. This study assessed the impact of a probiotic containing a mixture of Lacticaseibacillus casei, Limosilactobacillus fermentum, Levilactobacillus brevis, and Enterococcus faecium on the gut microbiota of six dogs using short-term colonic simulations. Two groups were included, i.e., blank versus supplementation with the test product, and incubated for 48 h. Probiotic-supplemented reactors had significantly greater fermentative activity compared with the blank, as shown by lower pH levels and higher gas pressure after 6 h, 24 h, and 48 h of incubation (p < 0.05 for all). Saccharolytic fermentation also increased, with a significantly higher level of acetate at 24 h and propionate at 6 h, 24 h, and 48 h with the test product versus blank (p < 0.05 for all). There was no significant effect of the test product on alpha-diversity, but beta-diversity analysis revealed a clear separation in the microbial community composition between the test product and blank. Eight bacterial taxa were enriched with test product supplementation, including the probiotic test strains as well as Megamonas and Bacteroides species. This study, using in vitro short-term colon simulations with six canine donors, provides insights into the probiotic characteristics of the test product.

La première ovulation induite par effet mâle chez la brebis anovulatoire en anoestrus saisonnier est souvent accompagnée d’un développement de cycles courts qui peuvent être contrecarrés par un traitement progestatif préalable. Nos travaux ont montré que la réponse au mâle est plus rapide en fin d’anoestrus en raison d’une sélection à J0 de follicules dont le stade de développement est plus avancé. En parallèle, ils apportent de nouvelles connaissances sur le mécanisme d’action par lequel la progestérone parvient à supprimer les cycles courts induits par effet mâle, en modulant certaines caractéristiques de la dynamique de croissance folliculaire et en améliorant l’activité stéroïdogénique des follicules préovulatoires. Cependant, d’autres études sont nécessaires pour étudier l’impact de ces effets sur la qualité ovocytaire et la fertilité de ces premières ovulations induites par effet mâle sur un plus grand nombre d’animaux.