Autism spectrum disorder (ASD) is a complex heterogeneous neurodevelopmental disorder affecting approximately 1 in 100 children worldwide. A number of comorbidities are associated with ASD, including gastrointestinal problems, which can include various symptoms such as abdominal pain, diarrhea and vomiting. Gastrointestinal dysfunction has been reported in as many as 93% of children diagnosed with ASD. Whilst differences in dietary intake and in gut microbiome composition have been suggested to contribute to these gastrointestinal problems in children with ASD, the mechanisms behind this remain unclear.
The gut microbiome consists of a diverse range of microorganisms with at least 1,000 different bacterial species. The microbiome has been implicated in various roles including fermentation of polysaccharides maintenance of the immune system and gut motility. An individuals’ core microbiome varies greatly over time and evidence suggests factors including age, diet and genetics play a role in the establishment and maintenance of its composition. It has been proposed that alterations to the core microbiome can lead to gastrointestinal dysfunction and diseases such as irritable bowel syndrome (IBS).
A missense mutation in the gene encoding neuroligin 3 (Nlgn3) has been identified in patients with ASD. This mutation disrupts synaptic function. Using a transgenic mouse model of autism, we aim to determine whether the Nlgn3 R451C mutation associated with ASD plays a role in gastrointestinal dysfunction.
In this study, changes in microbial community composition and community function in the intestinal microbiome of mutant and wild-type mice were investigated over time. By 10 weeks of age there were specific difference in the microbiome community fingerprint of the mouse model. By using a genetically defined model we conclude that the differences observed between the “autistic” and wild-type mice are not due to environmental factors.