Department of Food Science and Nutrition, University of Minnesota, St Paul, Minnesota 55108, USA.
J Med Food. 2010 Aug;13(4):961-6. doi: 10.1089/jmf.2009.0135.
Dietary fiber fermentation decreases luminal pH by the production of short-chain fatty acids (SCFAs). Additional proposed physiological benefits of fiber fermentation include decreased growth of pathogenic bacteria, increased mineral absorption, and serving as an energy source for the colon epithelium. This study examined three common fiber supplements--wheat dextrin (WD) (Benefiber, Novartis Consumer Health Inc., Parsippany, NJ, USA), psyllium (PS) (Metamucil, Procter & Gamble, Cincinnati, OH, USA), and inulin (Fiber Sure, Procter & Gamble)--for pH, SCFAs, and gas production. An established in vitro fermentation model was used to simulate colonic fermentation at 0, 4, 8, 12, and 24 hours. At 24 hours, WD and inulin significantly decreased pH compared to PS. Inulin produced significantly more hydrogen and total gas. All treatments produced similar total SCFA concentrations at 24 hours; however, the rate of production was different. PS had a declining rate of SCFA production from 12 to 24 hours, whereas WD and inulin had a higher rate during that period. Fast-fermenting substrates may not provide as much SCFAs to the distal colon as slow-fermenting substrates. Differences in fermentation rate, gas production, and SCFA production observed for WD, PS, and inulin may affect their gastrointestinal tolerance and require further study.
膳食纤维发酵通过产生短链脂肪酸 (SCFA) 来降低腔液 pH 值。纤维发酵的其他预期生理益处包括减少致病菌的生长、增加矿物质吸收以及为结肠上皮提供能量来源。本研究检查了三种常见的纤维补充剂——小麦糊精 (WD)（Benefiber，诺华消费者健康公司，新泽西州帕西帕尼，美国）、车前子壳 (PS)（Metamucil，宝洁公司，俄亥俄州辛辛那提）和菊粉 (Fiber Sure，宝洁公司）——用于 pH 值、SCFA 和气体产生。使用已建立的体外发酵模型模拟结肠发酵 0、4、8、12 和 24 小时。在 24 小时时，WD 和菊粉与 PS 相比显着降低 pH 值。菊粉产生的氢气和总气体明显更多。所有处理在 24 小时时产生相似的总 SCFA 浓度；然而，产生的速率不同。PS 的 SCFA 产生率从 12 小时到 24 小时呈下降趋势，而 WD 和菊粉在此期间的产生率较高。快速发酵的底物可能不会像慢速发酵的底物那样向远端结肠提供那么多的 SCFA。WD、PS 和菊粉在发酵速率、气体产生和 SCFA 产生方面观察到的差异可能会影响它们的胃肠道耐受性，需要进一步研究。
