咖啡摄入量对小鼠肠道微生物及酶活性的影响

目的 研究摄入不同咖啡浓度对小鼠酶活性、肠道微生物、体重的影响，从分析肠道四种微生物变化和四种酶的活性变化来讨论摄入咖啡对健康的影响。方法 SPF级昆明小鼠随机分为4组，即低、中、高咖啡浓度组和正常对照组，所有实验组小鼠日常给予蒸馏水饮用，实验低、中、高浓度组每天2次分别灌胃给予0.0045 g/mL、0.0090 g/mL、0.0180 g/mL的咖啡溶液0.4 mL/（只•次），对照组给予蒸馏水灌胃，实验时间为1个月，测小鼠体重、肠道微生物和酶活性等指标并进行分析。结果 与对照组相比，低浓度咖啡摄入组乳杆菌、双歧杆菌、大肠埃希菌数显著增加（P＜0.01或P＜0.05），需氧和厌氧细菌数显著降低（P＜0.01）；中浓度咖啡摄入组乳杆菌、双歧杆菌数显著低于对照组和低浓度组（P＜0.01），大肠埃希菌显著高于对照组（P＜0.05）；高浓度咖啡摄入组乳杆菌和大肠埃希菌总数显著低于对照组（P＜0.01或P＜0.05）；低浓度摄入组的木聚糖酶、纤维素酶、淀粉酶、蛋白酶的活性均显著高于（Ps＜0.01）对照组和中浓度咖啡摄入组；各组小鼠体重差异无统计学意义（P＞0.05）。结论 适当摄入咖啡小鼠肠道双歧杆菌和乳杆菌等益生菌数量增加显著，小鼠肠道中具有代表性的淀粉酶、纤维素酶、蛋白酶、木聚糖酶的活性均显著增加，但咖啡摄入对小鼠体重影响不显著。

Effect of coffee intake on the intestinal microbiota and enzyme activities in mice

Abstract: Objective To explore the effect of coffee intake on intestinal bacteria, enzyme activities and weight of mice. Methods The mice were divided into 4 groups and given distilled water for drinking freely; the three observation groups were additionally given 0.0045 g/mL (low dose group), 0.0090 g/mL (medium dose group) or 0.0180 g/mL (high dose group) of coffee solution while the control group was given distilled water, 0.4 mL bid by gavage for one month. After a month, the enzyme activities, body weight and intestinal microorganisms in each group were detected. Results The amounts of Lactobacilli, Bifidobacteria and Escherichia coli in the low dose group increased markedly than in the control group (P<0.01 or P<0.05); those of aerobic and anaerobic bacteria reduced sharply (P<0.01). In medium dose group, the amounts Lactobacilli and Bifidobacteria were lower than in the control group and low dose group (P<0.01), while that of Escherichia coli was higher than in the control group (P<0.05). The amounts of Lactobacilli and Escherichia coli in high dose group were significantly lower than in the control group (P<0.01 or P<0.05). The activities of protease, cellulase, amylase and xylanase in the low dose group were significantly higher than in control group and medium dose group (Ps<0.01). There were no obvious differences in body weight among all groups (P>0.05). Conclusion Appropriate coffee intake can increase the amounts of intestinal probiotics including Lactobacilli and Bifidobacteria, and improve the activities of intestinal enzymes in mice.