Discuss Altered Gut Microbiota and Short-chain Fatty Acids in Chinese Children with Constipated Autism Spectrum Disorder

Inclusion criteria of the constipated autism spectrum disorder (C-ASD) group were as follows: (1) aged 3 to 10 years; (2) diagnosed with autism spectrum disorder according to the Diagnostic and Statistical Manual of Mental Disorders, fifth edition (DSM-V) criteria (CARS score ≥ 30 and ABC total score ≥ 67); and the International Statistical Classification of Diseases and Related Health Problems (ICD-10). (3) presence of GI comorbidities according to the Childhood Functional Gastrointestinal Disorders criteria (2016)66. (4) The guardians of each patient signed an informed consent form to allow the investigator to collect clinical data, faeces, and other samples.

exclusion criteria before faecal sample collection: (1) definite diagnosis of Rett syndrome; (2) a clear history of brain injuries, cerebral palsy, encephalitis or other organic brain diseases; (3) a family history of serious mental illness or substance abuse; (4) use of probiotics, antibiotics, acid suppressors or other drugs affecting the gut microbiota in the last three months; (5) the presence of intestinal organic diseases, such as congenital megacolon, intestinal obstruction, intussusception and developmental disorder-related genetic diseases; (6) developmental quotient score < 35; or (7) participation in other clinical trials that would affect the evaluation of the study results.