In-depth Understanding of Gastrointestinal (GI) Problems in Autism Spectrum Disorder (ASD): Nature, Expression, and Possible Therapeutic Approaches

Autism Spectrum Disorder (ASD) is a relatively frequent disorder with a high longitudinal diagnostic stability (Prosperi 2010), characterized by a significant individual, familial, and societal burden (Horlin et al. 2014). Gastrointestinal (GI) problems are more frequent in children with ASD than in typically developing (TD) peers (Prosperi 2016) and are associated with low functioning and high psychiatric symptoms (Prosperi et al. 2017). This dissertation offers a possible analysis and interpretation of GI symptoms through a psychiatric perspective based on various clinical and biochemical investigations. The first part is an overview with an introductory critical analysis of the literature and a description of the findings emerging from the specific research I have dealt with, all investigating GI problems in children with ASD. Studies concerning the microbiota-gut-brain axis with their therapeutical implications, the results of a survey concerning eating habits and the findings of a prevalence study on celiac disease are summarized. The second part concerns a randomized controlled study on the role of probiotics on clinical and biochemical parameters funded by the Italian Ministry of Health concerning a sample of preschoolers with ASD (Santocchi et al. 2016). The results were presented by chapters, partitioning the sample into subgroups based on the data available for each experimental question. As shown below, children with ASD and GI symptoms exhibit their disturbances with different behaviors than TD children, have a particular intestinal microbiota and fecal metabolome than children with ASD without GI symptoms, and the nature of their disturb is more likely functional than organic. Promising results emerge from a clinical trial with probiotics on GI symptoms and behavioral features for children with ASD. Future experimental trials considering TD control samples will provide a baseline and significantly empower the robustness of some of these promising findings.