孤独症谱系障碍（ASD）是一种广泛性发育障碍类疾病，目前已成为儿童精神类致残的常见疾病。目前尚无针对ASD核心症状的确切治疗方法。有研究表明ASD儿童广泛存在饮食偏好，且61% ASD儿童伴有至少一种胃肠道症状。我们前期研究发现65%的ASD儿童伴有肠道症状，且其血清VA水平明显低于正常儿童， VA补充后可缓解ASD儿童的肠道症状，减少血清5-HT含量，而且还降低ASD儿童CARS得分，减轻ASD行为症状。那么我们能否利用前一个NSFC研究结果-VA显著增强肠道屏障功能特性，对ASD儿童进行VA干预，进而通过脑肠轴系统达到治疗ASD行为呢？本项目拟以改善肠道屏障功能为切入点，通过临床调查分析阐明补充VA改善ASD儿童胃肠道问题缓解其核心行为症状的作用，再利用动物模型及体外细胞水平研究，揭示补充VA改善ASD临床症状的可能分子机制及作用靶点，为临床治疗胃肠型ASD儿童提供一条新的治疗方案。

Autism spectrum disorder (ASD) is a kind of pervasive developmental disorder, and has currently become a common cause of mental disability in children. However, so far there is no exact treatment for the core behavioral symptoms. Some studies suggest that ASD children have a wide range of the dietary preferences problem, and there were 61% ASD children with at least one gastrointestinal symptom. Our previous studies found that 65% of ASD chilsren accompanied with intestinal problem, and the level of serum retinal in ASD children was significantly decreased compared with that of health children. VA supplementation alleviated the intestinal symptoms and reduced level of serum 5-HT in children with ASD, but also decreased score of CARS and attenuated behavioral symptoms in children suffered with ASD. Therefore, whether would we take the results of our previous NSFC project- VA significant enhancing intestinal barrier function to intervention in ASD chidlren with VA, which can achieve ASD core behavior symptoms via the brain-gut axis regulation system? The present project will take improvement of intestinal barrier function as a key ponit, to clarify the role of VA in improving gastrointestinal problems in the children with ASD to alleviate their core behavioral symptoms through clinical investigation and analysis. And then combining animal model with cell level in vitro studies are used to reveal the possible molecular mechanisms and target of VA improving clinical symptoms of ASD children. The project will provide a new clinical treatment for children with gastrointestinal ASD.