卫生研究

目的研究补充益生菌和酸奶对乳糖不耐者结肠菌群的影响。方法以经25g乳糖负荷试验筛选的乳糖不耐受者11名为对象,让受试者持续摄入益生菌(含B.longum)和酸奶(含B.animalis,L.bulgaricus,S.thermophilus)14天进行补充研究。试验分3阶段:即补充前阶段7天,补充阶段14天,补充后阶段7天。在补充阶段开始前1天和结束后1天分别进行乳糖不耐受负荷试验,记录受试者不耐受症状并评分。在试验阶段收集受试者的新鲜粪便样本共5次,采用荧光原位杂交技术(FISH)和变性梯度凝胶电泳技术(DGGE)检测补充前、补充期间和补充后粪便样本细菌总数和各主要菌群的数量构成,以及外源性和内源性双歧杆菌菌种分布。结果在补充益生菌胶囊和酸奶后受试者乳糖不耐受症状评分均显著降低(P<0·05)。补充期间细菌总数和主要细菌组(Bifidobacteria,Bacteroides-Prevotella,Eubacteria,Ruminccocc等)的数量均显著高于补充前(P<0·05),双歧杆菌的数量在补充结束后7天仍显著高于补充前(P<0·05),其他几组细菌数量在补充结束后下降;DGGE结果显示来自益生菌胶囊和酸奶的双歧杆菌菌种在补充期间能够在受试者肠道内检出,但个体间存在较大差异。结论益生菌胶囊和酸奶中的双歧杆菌能够耐受胃肠的酸碱环境在结肠内存活和繁殖,并影响内源性双歧杆菌和其他细菌组的数量,改变结肠菌群的构成,尤其以双歧杆菌更为明显,这对减轻乳糖不耐受症状起到重要作用。

Objective To study the effects of probiotics and yoghurt supplementation on colonic microflora in subjects with lactose intolerance (LI). Methods Eleven lactose intolerant volunteers determined by 25g lactose challenge test were recruited and given supplementation with Bifina capsule (with B. longum) and yogurt (with B. animalis, L. bulgaricus, S. thermophilus) for 14 days. The trial was divided into 3 phases: 7-day basal period, 14-day supplementation period and 7-day post-supplementation period. Two lactose challenge tests were performed 1 day before and 1 day after supplementation period respectively, and lactose intolerance symptoms were recorded with questionnaires. Five fecal samples were collected during the trial, and total bacteria and several main groups of bacteria in colon were analyzed by fluorescence in situ hybridization (FISH). The shift of Bifidobacterium species population in colon was analyzed by denaturing gradient gel electrophoresis (DGGE). Results It was found that LI symptom was alleviated significantly after supplementation (P<0.05). The amount of total bacteria and the main groups of bacteria (Bifidobacteria, Bacteroides-Prevotella, Eubacteria, Ruminccocc, et al.) was significantly increased during the supplementation period (P<0.05). The amount of Bifidobacteria during post-supplementation period was significantly higher than that of basal period (P<0.05), while the amount of other several groups of bacteria decreased. The result of DGGE showed that the extraneous Bifidobacteria species from Bifina capsule and yoghurt could be detected in fecal samples during supplementation period, however there was diversity between volunteers. Conclusion It was suggested that extraneous Bifidobacteria in Bifina capsule and yogurt could resist the effect of gastric acid and bile salt, and survive in colon. Supplementation of probiotics and yogurt could influence the colonic bacteria, and increase the number of main groups of colonic microflora, especially for Bifidobacteria, which could play important role in alleviating LI symptoms.