Monsma D J, Marlett J A
Department of Nutritional Sciences, University of Wisconsin-Madison 53706, USA.
J Nutr. 1995 Oct;125(10):2463-70. doi: 10.1093/jn/125.10.2463.
The effects of bacterial collection site, bacterial adaption to substrate and duration of fermentation on short-chain fatty acid (SCFA) production were studied using an in vitro fermentation system. Cecal and fecal inocula from rats fed purified diets containing 100 g/kg dietary fiber from canned peas or psyllium seed husk, or a nonpurified diet containing 170 g/kg dietary fiber fermented ileal excreta from colectomized rats fed a purified diet containing 100 g/kg dietary fiber from canned peas. The SCFA concentration, measured by gas chromatography, in anaerobic fermentations of 0, 3, 6, 12, 24, 48, 72 and 96 h, increased (P < 0.05) through 72 h. Compared with fecal inocula, cecal inocula produced SCFA at greater (P < 0.05) initial rates, more (P < 0.05) total SCFA and a greater (P < 0.05) proportion as n-butyrate. Inocula from rats fed the pea or nonpurified diets produced SCFA at greater (P < 0.05) molar proportions as acetate and less (P < 0.05) as propionate than inocula from rats fed psyllium seed husk at most time points. We conclude that collection site, adaptation of bacteria to the substrate to be fermented and duration of fermentation significantly influence the results of in vitro fermentation studies.
使用体外发酵系统研究了细菌采集部位、细菌对底物的适应性以及发酵持续时间对短链脂肪酸（SCFA）产生的影响。来自喂食含100 g/kg来自罐装豌豆或车前草籽壳膳食纤维的纯化日粮的大鼠的盲肠和粪便接种物，或来自喂食含100 g/kg来自罐装豌豆膳食纤维的纯化日粮的结肠切除大鼠的含170 g/kg膳食纤维的非纯化日粮发酵回肠排泄物。通过气相色谱法测定的在0、3、6、12、24、48、72和96小时厌氧发酵中的SCFA浓度在72小时内增加（P<0.05）。与粪便接种物相比，盲肠接种物产生SCFA的初始速率更高（P<0.05），总SCFA更多（P<0.05），且作为正丁酸的比例更大（P<0.05）。在大多数时间点，喂食豌豆或非纯化日粮的大鼠的接种物产生的SCFA中乙酸盐的摩尔比例更高（P<0.05），而丙酸盐的摩尔比例更低（P<0.05），比喂食车前草籽壳的大鼠的接种物。我们得出结论，采集部位、细菌对要发酵的底物的适应性以及发酵持续时间显著影响体外发酵研究的结果。
