Autism spectrum disorder (ASD) is characterized by the presence of restricted/repetitive behaviors and social communication deficits. Because effective treatments for ASD remain elusive, novel therapeutic strategies are necessary. Preclinical studies show that L. reuteri selectively reversed social deficits in several models for ASD. Here, in a double-blind, randomized, placebo-controlled trial, we tested the effect of L. reuteri (a product containing a combination of strains ATCC-PTA-6475 and DSM-17938) in children with ASD. The treatment does not alter overall autism severity, restricted/repetitive behaviors, the microbiome composition, or the immune profile. However, L. reuteri combination yields significant improvements in social functioning that generalized across different measures. Interestingly, ATCC-PTA-6475, but not the parental strain of DSM-17938, reverses the social deficits in a preclinical mouse model for ASD. Collectively, our findings show that L. reuteri enhances social behavior in children with ASD, thereby warranting larger trials in which strain-specific effects should also be investigated.

自闭症谱系障碍 (ASD) 的特点是存在受限/重复行为和社交沟通缺陷。由于 ASD 的有效治疗方法仍然难以捉摸，因此需要新的治疗策略。临床前研究表明，罗伊氏乳杆菌选择性地逆转了几种自闭症谱系障碍模型中的社交缺陷。在一项双盲、随机、安慰剂对照试验中，我们测试了罗伊氏乳杆菌（一种含有 ATCC-PTA-6475 和 DSM-17938 菌株组合的产品）对 ASD 儿童的效果。该治疗不会改变自闭症的总体严重程度、受限/重复行为、微生物组组成或免疫特征。然而，罗伊氏乳杆菌组合显着改善了社会功能，这在不同的衡量标准中都得到了推广。有趣的是，ATCC-PTA-6475（而非 DSM-17938 的亲本品系）逆转了 ASD 临床前小鼠模型的社交缺陷。总的来说，我们的研究结果表明，罗伊氏乳杆菌可以增强自闭症谱系障碍儿童的社会行为，因此需要进行更大规模的试验，其中还应研究菌株特异性的影响。