Survival of Six Probiotic Strains During Simulated Gastrointestinal Digestion in Fermented Sheep’s Milk Supplemented with Inulin and Sodium Butyrate

Background/Objectives: The aim of this study was to produce fermented sheep milk and to evaluate its microbiological properties. In addition, the survival of six probiotic strains was assessed using a standardized static in vitro digestion model. Methods: Fermented sheep milk samples supplemented with inulin or with the combination of inulin and sodium butyrate were analyzed using a standardized in vitro digestion procedure simulating oral, gastric, and intestinal phases. The survival rate of probiotic bacteria was additionally calculated. Results: The viable cell counts in sheep milk prior to digestion were significantly influenced by the bacterial strain used for fermentation. Analysis of variance demonstrated that probiotic survival during simulated gastrointestinal digestion was significantly affected by the investigated factors (bacterial strain, inulin supplementation, and supplementation with inulin and sodium butyrate), as well as by the interactions among these factors. The effects of supplementation on probiotic survival were strain-dependent. Conclusions: Considering the limited data available regarding the effects of sodium butyrate and inulin on probiotic survival in sheep milk matrices, the obtained results indicate that supplementation with these compounds may modulate the survival of probiotic strains during simulated gastrointestinal digestion in a strain-dependent manner. This study provides new insights into the influence of sodium butyrate and inulin on probiotic viability and gastrointestinal tolerance in fermented sheep milk.