Background: Autism Spectrum Disorder (ASD) is a condition strongly associated with genetic predisposition and familial aggregation. Among ASD patients, different levels of symptoms severity are detectable, while the presence of intermediate autism phenotypes in close relatives of ASD probands is also known in literature. Recently, increasing attention has been paid to environmental factors that might play a role in modulating the relationship between genomic risk and development and severity of ASD. Within this framework, an increasing body of evidence has stressed a possible role of both gut microbiota and inflammation in the pathophysiology of neurodevelopment. The aim of this paper is to review findings about the link between microbiota dysbiosis, inflammation and ASD.

Methods: Articles ranging from 1990 to 2018 were identified on PUBMED and Google Scholar databases, with keyword combinations as: microbiota, immune system, inflammation, ASD, autism, broad autism phenotype, adult.

Results: Recent evidence suggests that microbiota alterations, immune system and neurodevelopment may be deeply intertwined, shaping each other during early life. However, results from both animal models and human samples are still heterogeneous, while few studies focused on adult patients and ASD intermediate phenotypes.

Conclusion: A better understanding of these pathways, within an integrative framework between central and peripheral systems, might not only shed more light on neural basis of ASD symptoms, clarifying brain pathophysiology, but it may also allow to develop new therapeutic strategies for these disorders, still poorly responsive to available treatments.

背景：自闭症谱系障碍（ASD）是与遗传易感性和家族聚集密切相关的疾病。在ASD患者中，可以检测到不同程度的症状严重程度，而在ASD先证者的近亲中存在中间自闭症表型。最近，人们越来越关注可能在调节基因组风险与ASD的发展和严重性之间的关系中发挥作用的环境因素。在此框架内，越来越多的证据强调肠道菌群和炎症在神经发育的病理生理中可能发挥的作用。本文的目的是回顾有关微生物群失调，炎症和自闭症之间的联系的发现。

方法：从1990年至2018年的文章在PUBMED和Google Scholar数据库中进行鉴定，关键词组合为：微生物群，免疫系统，炎症，ASD，自闭症，广泛自闭症表型，成人。

结果：最近的证据表明，微生物群的变化，免疫系统和神经发育可能在生命的早期相互交织在一起。然而，来自动物模型和人类样品的结果仍然是异质的，而很少有研究关注成年患者和ASD中间表型。

结论：在中枢和外周系统之间的整合框架内对这些途径的更好理解，不仅可以从神经方面了解ASD症状，阐明脑病理生理学，而且还可以为这些疾病开发新的治疗策略，仍然对可用治疗反应不佳。