The outer cell wall of yeast is characterized by high levels of β-glucans and mannan-oligosaccharides (MOS), which have been linked with beneficial effects on intestinal health and immune status in dogs. In this study, a standardized in vitro simulation of the canine gastrointestinal tract (Simulator of the Canine Intestinal Microbial Ecosystem; SCIME) was used to evaluate the effect of a Saccharomyces cerevisiae-based product, consisting of 27.5% β-glucans and 22.5% MOS, on the activity (as assessed by measurement of fermentative metabolites) and composition (as assessed by 16S-targeted Illumina sequencing) of canine intestinal microbiota. The S. cerevisiae-based product was tested at three different dosages, i.e., 0.5, 1.0, and 2.0 g/d. A dose-dependent fermentation pattern was observed along the entire length of the colon, as shown by the increased production of the health-related acetate, propionate, and butyrate for the three concentrations tested (0.5, 1.0, and 2.0 g/d). A consistent finding for all three tested concentrations was the increased propionate production (P < 0.05) in the simulated proximal and distal colon. These changes in terms of fermentative metabolites could be linked to specific microbial alterations at the family level, such as the specific stimulation of the propionate-producing families Porphyromonadaceae and Prevotellaceae upon in vitro exposure to the S. cerevisiae-based product. Other consistent changes in community composition upon repeated exposure included the decrease in the Enterobacteriaceae and the Fusobacteriaceae families, which both contain several potentially opportunistic pathogens. Altogether, the generated data support a possible health-promoting role of a product high in β-glucans and MOS when supplemented to the dogs’ diet.

中文翻译：

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富含β-葡聚糖和甘露寡糖的干酵母细胞壁对体外犬胃肠道中的微生物组成和活性产生积极影响。


酵母外细胞壁的特点是含有高水平的 β-葡聚糖和甘露寡糖 (MOS)，这对狗的肠道健康和免疫状态有有益影响。在本研究中，使用犬胃肠道的标准化体外模拟（犬肠道微生物生态系统模拟器；SCIME）来评估基于酿酒酵母的产品的效果，该产品由 27.5% β-葡聚糖和 22.5% MOS 组成，关于犬肠道微生物群的活性（通过测量发酵代谢物评估）和组成（通过 16S 靶向 Illumina 测序评估）。以三种不同的剂量，即0.5、1.0和2.0g/d，测试基于酿酒酵母的产品。沿着结肠的整个长度观察到剂量依赖性发酵模式，如在三个测试浓度（0.5、1.0 和 2.0 g/d）下与健康相关的乙酸盐、丙酸盐和丁酸盐的产量增加所表明的。所有三个测试浓度的一致发现是模拟近端和远端结肠中丙酸产量增加（ P < 0.05）。发酵代谢物方面的这些变化可能与科水平上的特定微生物改变有关，例如在体外暴露于基于酿酒酵母的产品时产生丙酸盐的科紫单胞菌科和普氏菌科的特定刺激。反复接触后群落组成的其他一致变化包括肠杆菌科和梭杆菌科的减少，它们都含有几种潜在的机会性病原体。 总而言之，生成的数据支持将富含 β-葡聚糖和 MOS 的产品添加到狗的饮食中可能具有促进健康的作用。