To determine variations in gut bacteriome and mycobiome between individuals with neurodevelopmental disorders, gastrointestinal disorders, and healthy controls in a multiethnic cohort.  

Gastrointestinal disorders (GID) are common among individuals with neurodevelopmental disorders (NDD), while anxiety-like behavior is common among those with GID. There is evidence of bidirectional communication between the gut and the brain constituting the gut-brain-axis. Gut dysbiosis has been linked to these conditions but specific differences between the two groups are yet to be delineated.  

We enrolled 55 participants living in Qatar (15 with NDD, 13 with GID, and 27 healthy controls) aged from 3 to 57 years old. Participants provided a stool sample and data pertaining to their age, gender, height, weight, diet, type, medical history, ethnicity, and use of antibiotics in the first 3 years of life. 16sRNA and internal transcribed spacers sequencing was performed to analyze the bacterial and fungal compositions, respectively.  

Both NDD and GID groups showed decreased bacterial alpha diversity while fungal alpha diversity was increased in NDD compared to healthy controls. Firmicutes/Actinobacter ratio was reduced in NDD compared to both groups (p=0.030). In the NDD group, there was an increase in the Corynebacteriaceae family and Odoribacter genus only when diet and probiotic intake were considered (p=0.042, p=0.047). The relative abundance of the Saccharomyces genus was increased in NDD compared to both groups (p=0.004). Exposure to antibiotics in the first 3 years of life was associated with greater fungal dysbiosis than bacterial dysbiosis.  

Bacterial dysbiosis was apparent in both groups, but a more pronounced difference in gut mycobiota is seen in NDD compared to GID. Main factors that contributed to mycobiome dysbiosis are probiotic intake, diet, and antibiotic exposure.