A quarterly publication of the Autism Research Institute

The Autism Research Review International is quarterly publication of the Autism Research Institute

Winter, 2018 | Number 1, Volume 32

Differences in oral microbes detected in children with ASD

While many researchers are studying the gut microbes of children with autism spectrum disorders (ASD), a new study from China examined their dental and saliva microbes, finding significant differences between the children with ASD and neurotypical controls. 

Yanan Qiao and colleagues sequenced 111 samples from 32 children with ASD and 27 controls. They report, “Lower bacterial diversity was observed in ASD children compared to controls, especially in dental samples.” Moreover, they say, “pathogens such as Haemophilus in saliva and  Streptococcus in [dental] plaques showed significantly higher abundance in ASD patients, whereas commensals [non-harmful microbes] such as Prevotella, Selenomonas, Actinomyces, Porphyromonas, and Fusobacterium were reduced.” Further analysis, they say, indicated that ASD was not only associated with a decreased richness of commensals, “but also related to reduced mutual effects within these bacteria.” 

In particular, the researchers note the depletion of Prevotella. “It does not only interact with the immune system,” they say, “but also plays a key role in degrading a broad spectrum of saccharides [sugars]. Interestingly, it was reported that autistic children may have deficiencies in saccharide metabolism and impaired carbohydrate digestion.” They add, “Prevotella species also have essential genes for the biosynthesis of vitamins, which were reported to mitigate ASD symptoms.” 

The researchers also found an association between the pathogenic microbes that were elevated in the children with ASD and the severity of the children’s symptoms. In addition, diagnostic models based on key microbes predicted autism with high accuracy, which the researchers speculate may make these models useful in diagnosing ASD.


“Alterations of oral microbiota distinguish children with autism spectrum disorders from healthy controls,” Yanan Qiao, Mingtao Wu, Yanhuizhi Feng, Zhichong Zhou, Lei Chen, and Fengshan Chen, Nature Scientific Reports, January 25, 2018 (online). Address: Fengshan Chen, [email protected].