老年人肠道菌群与肠道黏膜免疫相关性分析

目的 探讨老年人肠道菌群的特点及对粪便中肠道分泌型免疫球蛋白A(SIgA)含量的影响. 方法 60岁以下健康成年人36例为对照组,60岁及以上老年人68例为老年组,分别取新鲜粪便,选择肠道菌群中7种具有代表性的细菌,包括4种厌氧菌、两种需氧和酵母样真菌,进行细菌培养和计数;计算出反映肠道定植抗力的指标双歧杆菌与肠杆菌比值(B/E).取新鲜粪便测定SIgA含量. 结果 老年组与对照组比较,肠道菌群中双歧杆菌数量减少,分别为(9.1±1.1)lgCFU/g和(10.2±0.8)lgCFU/g(t=-2.948,P<0.01);肠杆菌分别为(9.2±1.3)lgCFU/g和(8.2±0.7)lgCFU/g,差异有统计学意义(t=2.171,P<0.05);肠球菌分别为(8.5±1.4)lgCFU/g和(7.1±1.6)lgCFU/g,差异有统计学意义(t=2.564,P<0.05);肠道定植抗力分别为1.02±0.14和1.24±0.18,差异有统计学意义(t=-3.459,P<0.01),粪便中SIgA分别为(652.9±184.3)μg/ml和(793.5±150.3)μg/ml,差异有统计学意义(t=-2.178,P<0.05).双歧杆菌数量变化与粪便中SIgA水平相关(r=0.562,P<0.01). 结论 老年人肠道菌群中双歧杆菌数量减少,肠杆菌、肠球菌数量增加;老年人肠道定植抗力下降、肠黏膜免疫功能降低,与老年人肠道菌群改变相关.

Analysis of correlation between intestinal microflora and intestinal mucosa immune in the elderly

Objective To investigate the characteristics of intestinal microflora and its effect on fecal secretory immunoglobulin A (sIgA) in the elderly. Methods All 104 cases were assigned to two groups: the control group (healthy adults, age<60 years ,n=36) and the elderly group (healthy elderly persons, age ≥60 years, n=68). Feces samples of all cases were cultured under both aerobic and anaerobic conditions for the 6 bacteria (4 kinds of anaerobes and 2 kinds of aerobes) and the yeasts. The ratio of bifidobaeterium to Enterobacteria (the ratio of B/E) was calculated, which reflected personal colonization resistance. The fecal sIgA was also measured. Results Compared with control group, the number of fecal bifidobacterium and the ratio of B/E were significantly decreased in elderly group[(9.1±1.1)vs. (10.2±0.8)lgCFU/g,P<0. 01 ;(1. 02±0.14) vs. (1.24± 0. 18), P < 0. 01], and the number of enterobacteria and peptostreptococcus was significantly increased in elderly group [(9.2±1.3) vs. (8. 2±0.7) lgCFU/g, P < 0. 05 ; (8. 5 ±1.4) vs. (7.1 ± 1.6)lgCFU/g, P<0. 05]. The fecal slgA was much lower than that in control group [(652.9± 184.3) vs. (793. 5±150. 3)μg/ml, P<0. 05]. Moreover, the quantity change of bifidobacterium was correlated with the concentration of fecal sIgA(r=0. 562, P<0. 01). Conclusions The number of fecal bifidobacterium is significantly decreased, while the number of enterobacteria and peptostreptococcus is significantly increased in elderly persons. The colonization resistance is significantly decreased and the intestinal immuno-barrier function is injuried in elderly persons, which have influenced the intestinal microflora.