224. Yeast Probiotic Saccharomyces Cerevisiae Demonstrates High Survival in Simulated Canine Digestion: Insights from TIM1 FIDO in vitro Study.

Abstract Introduction Saccharomyces cerevisiae yeast probiotic (CNCM I-5660) Actisaf® Sc50 PET is formulated in a stable micropearl matrix and designed to enhance canine gut health by modulating microbiota, reducing faecal ammonia, and supporting mucosal immunity [1]. This study evaluated survival of this yeast probiotic through the canine gastrointestinal (GI) tract using the TIM1 FIDO in vitro model [2], simulating both fed (high/low-fibre kibbles) and fasted states. Animals, materials and methods The TIM1 FIDO system replicates canine gastric and small intestinal conditions, including dynamic pH, enzymes, and transit times. Two probiotic doses (0.6 g/kg [10⁸ CFU] and 15 g/kg [10⁹ CFU]) were tested with low-fibre and high-fibre kibbles or water (fed or fasted state respectively), each in triplicate. Ileal effluent samples were collected hourly over 6 hours, with CFU counts analysed via plate culture. Survival rates were calculated relative to initial intake, and data were assessed using a two-way ANOVA. Results and discussion Yeast probiotic Saccharomyces cerevisiae (CNCM I-5660; Actisaf® Sc50 PET) demonstrated robust survival, with ≤1 log reduction across all conditions. Fed states exhibited superior survival (0.5–0.6 log loss) compared to fasted (1 log loss; p < 0.0001) with a low-dose administration. High-dose administration with low-fibre kibble showed no loss, while high-fibre kibble and fasted states resulted in 95% and 94% survival, respectively. Survival in fed conditions was significantly higher (p < 0.0001) than fasted, with no notable difference between kibble types (p > 0.05). These results exceed typical bacterial probiotic survivals (0–10%). Conclusion The yeast probiotic Saccharomyces cerevisiae (Actisaf® Sc50 PET) survives canine GI transit effectively, particularly when co-administered with food. Its specialized micropearl formulation likely enhances stability, supporting its use as a probiotic petfood and pet supplement applications to promote canine gut health. This study underscores its potential as a functional ingredient in canine diets, offering reliable delivery of viable probiotics to the lower GI tract. References: [1] Bastos et al (2023) Microorganism 11(2):506, [2] Smeets-Peeters et al (1999) Alternatives to Laboratory Animals, 27(6), 935-949.