影响肠道细菌发酵因素的体外研究

目的 :　体外研究不同因素对肠道细菌发酵产生短链脂肪酸的影响 ,为膳食改善肠道功能提供依据。方法 :　在体外进行细菌培养 ,用稳定性同位素标记的葡萄糖作底物 ,用气相色谱 -同位素比值质谱法测定短链脂肪酸。用荧光染色法计数细菌数量。结果 :　结果显示细菌数量高 ,短链脂肪酸产生多 ,p H=7时产生的短链脂肪酸最多 ;添加酪蛋白可增加短链脂肪酸的产生及细菌数量 ;13 C-葡萄糖不但被发酵产生短链脂肪酸 ,而且也被用于细菌增殖。结论 :　人体肠道细菌发酵产生短链脂肪酸的能力受细菌数量、p H及底物不同的影响 ,此为通过选择不同膳食 (含益生原的食物如小麦、洋葱、香蕉、大蒜、韭菜、土豆等 )以调节结肠的功能提供了依据。

STUDY OF THE INFLUENCING FACTORS ON INTESTINAL BACTERIA FERMENTATION IN VITRO

Objective: The effect of different factors on short chain fatty acid production in bacteria incubation system was studied in vitro. The aim of the present study was to find the way of affecting the intestinal function in a beneficial way. Methods: The method of bacteria incubation in vitro was used. 13C-glucose was used as substrate and 13C-short chain fatty acids were measured using Gas Chromatography-Combustion-Isotope Ratio Mass Spectrometry. The amount of bacteria was counted by DAPI (4,6-diamidion-2-phenylindole) stain. Results: The results showed that δ value of short chain fatty acids production was higher in the bacteria incubation system with high amount of bacteria, pH 7 and casein supplementation. Conclusion: Short chain fatty acids production is influenced by the amount of bacteria, pH and casein supplementation in bacteria incubation system. The capacity of colon fermentation may be improved by selecting different food.