Short chain fatty acids (SCFAs) derived from the human gut microbiota, and in particular propionate, may beneficially influence metabolic processes such as appetite regulation. Development of prebiotics that induce high propionate levels during fermentation is desirable. A total of 11 candidate prebiotics were screened to investigate their fermentation characteristics, with a focus on propionate production in mixed anaerobic batch culture of faecal bacteria. Further to this, a continuous 3-stage colonic fermentation model (simulating the human colon) was used to evaluate changes in microbial ecology, lactate and SCFA production of three 50:50 blends, comprising both slow and rapidly fermented prebiotics. In mixed batch culture: xylo-oligosaccharide, polydextrose and α-gluco-oligosaccharide were associated with the greatest increase in propionate. Polydextrose, α-gluco-oligosaccharide, β-1,4 glucan and oat fibre induced the greatest reductions in the acetate to propionate ratio. The most bifidogenic prebiotics were the oligosaccharides. Fermentation of a 50:50 blend of inulin and arabinoxylan, through the continuous 3-stage colonic fermentation model, induced a substantial and sustained release of propionate. The sustained release of propionate through the colon, if replicable in vivo, could potentially influence blood glucose, blood lipids and appetite regulation, however, dietary intervention studies are needed. Bifidogenic effects were also observed for the inulin and arabinoxylan blend and an increase synthesis of butyrate and lactate, thus indicating wider prebiotic potential.

中文翻译：

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开发一种益生元混合物以影响肠道中的体外发酵效果，重点是丙酸盐

源自人类肠道微生物群的短链脂肪酸 (SCFA)，尤其是丙酸，可能有益于影响食欲调节等代谢过程。需要开发在发酵过程中诱导高丙酸水平的益生元。总共筛选了 11 种候选益生元以研究它们的发酵特性，重点是粪便细菌混合厌氧分批培养中的丙酸盐生产。此外，连续 3 阶段结肠发酵模型（模拟人类结肠）用于评估三种 50:50 混合物的微生物生态学、乳酸和 SCFA 生产的变化，包括缓慢和快速发酵的益生元。在混合分批培养中：木寡糖、聚葡萄糖和α-葡萄糖寡糖与丙酸盐的最大增加相关。聚葡萄糖、α-低聚葡萄糖、β-1,4 葡聚糖和燕麦纤维使乙酸与丙酸的比例降低幅度最大。最能产生双歧杆菌的益生元是低聚糖。50:50 的菊粉和阿拉伯木聚糖混合物的发酵，通过连续的 3 阶段结肠发酵模型，诱导大量和持续的丙酸盐释放。如果可复制，丙酸通过结肠持续释放在体内，可能会影响血糖、血脂和食欲调节，但需要进行饮食干预研究。还观察到菊粉和阿拉伯木聚糖混合物的双歧杆菌效应以及丁酸盐和乳酸盐的合成增加，从而表明具有更广泛的益生元潜力。