JAMA：益生菌的服用与抗菌素使用所致的腹泻风险的降低有关

5月9日，国际著名杂志《美国医学会杂志》JAMA上发表的一则对以往研究的综述及荟萃分析披露，益生菌的服用（活的微生物，它们会在诸如酸奶等食品中自然出现，人们对其的食用是为了赋予人体某种健康的裨益）与降低抗菌素相关性腹泻的风险——一种使用抗菌素的常见不良反应——有关。

根据文章的背景资料：“使用会干扰胃肠道菌群[微生物]的抗菌素与诸如腹泻等临床症状有关，而腹泻可在高达30%的病人中出现。这些症状范围涵盖从轻微及自限性的症状至严重症状——尤其是难辨梭状芽孢杆菌感染，而抗菌素相关性腹泻（AAD）是患者不坚持抗菌素治疗的一个重要原因。”益生菌可能在抗菌素治疗时或治疗后维持或恢复肠道的微生态系统（微生物生态学）。文章的作者写道：“人们对益生菌干预疗法的兴趣日增，而益生菌可有效防止或治疗AAD的证据也在增加。”

加州圣塔莫尼卡RAND Health的Susanne Hempel， Ph.D.及其同事们开展了一项研究，旨在对可获得的用益生菌来防止或治疗AAD的证据进行评估。综述作者对数据库进行了搜寻以发现涉及AAD和益生菌（乳酸菌，双歧杆菌，酵母菌，链球菌，肠球菌，和/或芽孢杆菌）的随机对照试验（RCTs）。共有82个RCTs符合纳入本研究的标准。

大多数的RCTs使用的是仅以乳酸菌为基础的干预或是乳酸菌与其它菌属（这是生物体系的次级细分）相结合的干预；对这些干预中的菌株的记录不良。在所有被纳入的试验中，有63个试验报告了发生腹泻的参与者的数字，以及随机分派至2个治疗组的参与者的数字。在所有的63个RCTs中（n = 11，811名参与者），与不用益生菌的对照组相比，益生菌的使用与发生腹泻风险降低42%有关。该结果在若干亚组中及敏感性分析中都是一致的。治疗效应等同于13这个需要治疗数字。

研究人员指出，在汇总的结果中存在着显著的异质性（跨越各项研究的差异），而确定这一关联是否会随着人群、抗菌素的特征或益生菌的制剂而发生系统性变化的证据不足。

文章的作者得出结论：“我们的综述发现有足够的证据可以得出结论：施予辅助性的益生菌与AAD风险的降低有关。这个一般性的结论很可能会掩盖在病人中、抗菌素中及益生菌菌株或混合物中存在的功效的异质性。未来的研究应该对这些因子进行评估并明确地评估不良反应的可能性以进一步地增进我们对用益生菌来防止AAD的理解。”

doi:10.1001/jama.2012.3507
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Probiotics for the Prevention and Treatment of Antibiotic-Associated Diarrhea

Susanne Hempel, PhD; Sydne J. Newberry, PhD; Alicia R. Maher, MD; Zhen Wang, PhD; Jeremy N. V. Miles, PhD; Roberta Shanman, MS; Breanne Johnsen, BS; Paul G. Shekelle, MD, PhD

Context Probiotics are live microorganisms intended to confer a health benefit when consumed. One condition for which probiotics have been advocated is the diarrhea that is a common adverse effect of antibiotic use. Objective To evaluate the evidence for probiotic use in the prevention and treatment of antibiotic-associated diarrhea (AAD). Data Sources Twelve electronic databases were searched (DARE, Cochrane Library of Systematic Reviews, CENTRAL, PubMed, EMBASE, CINAHL, AMED, MANTIS, TOXLINE, ToxFILE, NTIS, and AGRICOLA) and references of included studies and reviews were screened from database inception to February 2012, without language restriction. Study Selection Two independent reviewers identified parallel randomized controlled trials (RCTs) of probiotics (Lactobacillus, Bifidobacterium, Saccharomyces, Streptococcus, Enterococcus, and/or Bacillus) for the prevention or treatment of AAD. Data Extraction Two independent reviewers extracted the data and assessed trial quality. Results A total of 82 RCTs met inclusion criteria. The majority used Lactobacillus -based interventions alone or in combination with other genera; strains were poorly documented. The pooled relative risk in a DerSimonian-Laird random-effects meta-analysis of 63 RCTs, which included 11 811 participants, indicated a statistically significant association of probiotic administration with reduction in AAD (relative risk, 0.58; 95% CI, 0.50 to 0.68; P < .001; I2, 54%; [risk difference, −0.07; 95% CI, −0.10 to −0.05], [number needed to treat, 13; 95% CI, 10.3 to 19.1]) in trials reporting on the number of patients with AAD. This result was relatively insensitive to numerous subgroup analyses. However, there exists significant heterogeneity in pooled results and the evidence is insufficient to determine whether this association varies systematically by population, antibiotic characteristic, or probiotic preparation. Conclusions The pooled evidence suggests that probiotics are associated with a reduction in AAD. More research is needed to determine which probiotics are associated with the greatest efficacy and for which patients receiving which specific antibiotics.