Graduate School of Science and Technology, Shizuoka University.
Kyoto Institution of Nutrition and Pathology, Inc.
J Nutr Sci Vitaminol (Tokyo). 2024;70(2):139-149. doi: 10.3177/jnsv.70.139.
Since propionate exerts several physiological effects, maintenance of its normal colonic fermentation is essential. To investigate whether vitamin B (VB) is essential for normal propionate fermentation by colonic bacteria, via the succinate pathway, we examined if high-amylose cornstarch (HACS) feeding activated such a pathway, if high HACS feeding impaired propionate fermentation, and if oral VB supplementation normalized propionate fermentation. Male rats were given control, 20% HACS or 3% fucose diets (Expt. 1); a VB-free control diet or one supplemented with 5-30% HACS (Expt. 2); and the 20% HACS diet supplemented with 0.025-25 mg/kg of VB (Expt. 3), for 14 d. HACS feeding significantly increased cecal succinate concentration, activating the succinate pathway (Expt. 1). Cecal cobalamin concentration in 20% and 30% HACS groups was about 75% of that in the control group (Expt. 2). Cecal succinate and propionate concentrations significantly increased and decreased in 30% HACS groups, respectively, compared with the control group. Although HACS group supplemented with 0.025 mg/kg of VB had a low concentration of cecal propionate, adding high amounts of VB to HACS diets provided sufficient amounts of VB to rat ceca and increased cecal propionate concentration (Expt. 3). Compared with the non-HACS group, the relative abundance of Akkermansia muciniphila, but not Bacteroides/Phocaeicola, was lower in the HACS counterpart and showed improvement with increased VB doses. To summarize, feeding high HACS decreased and increased cecal VB and succinate concentrations, respectively. Furthermore, colonic delivery of sufficient amounts of VB to rats likely reduced accumulation of succinate and normalized propionate fermentation.
由于丙酸酯具有多种生理作用，因此维持其正常的结肠发酵至关重要。为了研究维生素 B（VB）是否通过琥珀酸途径对结肠细菌的正常丙酸酯发酵至关重要，我们检查了高直链淀粉玉米淀粉（HACS）喂养是否激活了这种途径，如果高 HACS 喂养会损害丙酸酯发酵，如果口服 VB 补充剂是否可以使丙酸酯发酵正常化。雄性大鼠分别给予对照、20%HACS 或 3%岩藻糖饮食（实验 1）；无 VB 对照饮食或补充 5-30%HACS 的饮食（实验 2）；和补充 20%HACS 饮食 0.025-25mg/kg VB（实验 3），为期 14 天。HACS 喂养显著增加盲肠琥珀酸浓度，激活琥珀酸途径（实验 1）。20%和 30%HACS 组盲肠钴胺素浓度约为对照组的 75%（实验 2）。与对照组相比，30%HACS 组盲肠琥珀酸和丙酸酯浓度分别显著增加和减少。尽管补充 0.025mg/kg VB 的 HACS 组盲肠丙酸酯浓度较低，但向 HACS 饮食中添加高剂量 VB 可为大鼠盲肠提供足够的 VB，并增加盲肠丙酸酯浓度（实验 3）。与非 HACS 组相比，HACS 组的 Akkermansia muciniphila 相对丰度较低，但 Phocaeicola 除外，随着 VB 剂量的增加，其相对丰度有所改善。总之，高 HACS 喂养分别降低和增加盲肠 VB 和琥珀酸浓度。此外，向大鼠结肠提供足够数量的 VB 可能会减少琥珀酸的积累并使丙酸酯发酵正常化。
