Background: A high prevalence of gastrointestinal (GI) symptoms has been reported in children with Autism Spectrum Disorders (ASD). However, results from studies about the GI mircobiome of such children have been inconsistent.
Aim: Integrate the results of studies that examine the distribution of different GI microorganisms in children with ASD.
Methods: Studies related to the GI microbiome in children with ASD were identified through PubMed, Embase, PsycINFO, ISI web of knowledge, Ovid/Medline, the Cochrane Library, the Chinese National Knowledge Infrastructure (CNKI) database, the Chongqing VIP database for Chinese Technical Periodicals, WANFANG DATA, and the China BioMedical Literature Service System (SinoMed). Studies were screened for inclusion following pre-defined inclusion and exclusion criteria. Software Review Manager 5.2.6 was used for statistical analysis.
Results: A total of 15 cross-sectional studies, all of which had relatively small samples, were included in the final analysis. Only one of the included studies was from China. Among the 15 studies, 11 studies (with a combined sample of 562 individuals) reported significant differences between ASD children and controls in the prevalence of GI bacteria, particularly bacteria in the Firmicutes, Bacteroidetes and Proteobacteria phyla. However, due to the substantial heterogeneity in methodology and the often contradictory results of different studies, it was not possible to pool the results into a meta-analysis.
Conclusions: To date, studies on the GI microbiome in children with ASD are limited in quantity and quality. There does, however, appear to be a 'signal' suggesting significant differences in the GI microbiome between ASD children and children without ASD, so there would be value in continuing this line of research. To improve validity and decrease the heterogeneity of findings, future studies should enlarge sample sizes, standardize methods and assess relevant confounding variables, such as the severity of GI symptoms and the use of medications, special diets and supplements.
背景: 有报道指出，孤独症谱系障碍（ASD）患儿的胃肠道（GI）症状发生率较高。然而，有关ASD患儿胃肠道微生物的研究结果不尽一致。
目的: 系统复习相关研究结果，分析ASD患儿各种胃肠道微生物的分布特征。
方法: 检索PubMed、Embase、PsycINFO、ISI web of knowledge、Ovid/Medline、Cochrane Library、中国知识资源总库、中国科技期刊数据库、万方数据检索系统，以及中国生物医学文献服务系统，收集有关ASD患者胃肠道微生物的文献，按照预先制定的纳入及排除标准筛选相关研究。采用Review manger 5.2.6软件进行统计分析。
结果: 最终共纳入15项小样本横断面研究，其中1项来自于中国。在15项研究中，11项研究（合并样本量为562例）报道ASD患儿组与对照组的胃肠道细菌患病率有显著性差异，尤其是厚壁菌门、拟杆菌门和变形菌门。但是，由于方法学上较大的异质性以及不同研究结果之间的相互矛盾，我们无法汇集结果进行meta分析。
结论: 目前对ASD患儿胃肠道微生物的研究数量和质量都非常有限。然而，似乎有迹象表明ASD患儿的胃肠道微生物和没有ASD的儿童是有显著差异的，因此，继续开展此方面的研究是非常有价值的。为了提高研究的效度、减少研究结果的异质性，将来的研究需要增大样本，应用标准化的研究方法并评估相关混杂因素，例如胃肠道症状的严重程度，以及药物，特殊饮食和营养补充品的使用情况。