应用荧光原位杂交技术分析乳糖不耐受者结肠菌群

目的 :　探讨结肠菌群构成与乳糖不耐受 (lactose intolerance,LI)症状之间的关系 ,以及饮奶对结肠双歧杆菌数量的影响。方法 :　根据乳糖负荷试验 ,结合问卷调查筛选成人乳糖吸收不良者、轻度及重度乳糖不耐受者作为试验对象。收集受试者一次新鲜全便 ,选用 5种特异性的 1 6S r RNA寡核苷酸探针 ,应用荧光原位杂交技术检测结肠细菌总数以及几种主要菌属 (种 )的构成。结果 :　乳糖不耐受组与吸收不良组相比 ,细菌总数和双歧杆菌数有显著性差异 (P<0 .0 5) ,细菌总数与乳糖不耐受症状评分之间呈负相关 (P<0 .0 5) ;每次饮奶以平均 2 0 0 ml计 5～ 7次 / w饮奶组与 0～ 2次 / w饮奶组或 0次 / w饮奶组相比 ,双歧杆菌数量显著增高 (P<0 .0 5)。结论 :　结肠细菌总数和双歧杆菌数可能与 LI症状的产生有关 ,同时饮奶习惯可能对双歧杆菌数量有潜在影响。

STUDY ON COLONIC MICROFLORA IN LACTOSE INTOLERANTS WITH FLUORESCENCE IN SITU HYBRIDIZATION

Objective: To study the relationship between colonic microflora and lactose intolerance symptoms. Methods: 42 volunteers were chosen and divided into lactose intolerance(LI) and lactose malabsorption groups according to the 25 g lactose-challenge test and symptoms questionnaires. Fresh fecal samples were collected from the volunteers, and the fluorescence in situ hybridization (FISH) technique with group-specific 16S rRNA-targeted oligonucleotide probes was used to quantify the total bacterial and predominant groups of bacteria in fecal samples. The effect of milk-drinking habit on the number of Bifidobacteria was analyzed. Results: It showed that there was significant difference in the number of total bacteria and Bifidobacteria between lactose intolerance groups and malabsorption group(P<0.05). A significantly negative correlation was found between the individual intolerance symptom scores and the number of total bacteria(P<0.05). Compared with 0～2 times/week and 0 times/week milk-drinking groups, the number of Bifidobacteria was significantly higher in the 5～7 times/week milk-drinking group(P<0.05). Conclusion: The occurrence of lactose intoler ance symptoms might be related to the amount of total bacteria and Bifidobacteria in the colon, and the milk-drinking habit could influence the number of Bifidobacteria.