Are 'leaky gut' and behavior associated with gluten and dairy containing diet in children with autism spectrum disorders?

Objectives: Studies have suggested a link between diet and behavior in children with autism spectrum disorders (ASDs). Parental reports of behavioral changes upon exposure to gluten and/or casein are common in clinical practice. An association between diet type, intestinal permeability (IP) ('leaky gut'), and behavior has been long proposed but not substantiated. We explored this possible association in this trial. Methods: This randomized double-blind, placebo-controlled study explored the effects of gluten and milk on IP and behavior in children with ASDs over a period of 4 weeks. IP assessed by lactulose: mannitol (L/M) sugar permeability test and behavior assessed by the Aberrant Behavior Checklist and Conners Parent Rating were measured. Gastrointestinal symptoms in both groups were also monitored. Results: Neither the L/M ratio nor behavioral scores were different between groups exposed to gluten/dairy or placebo. The changes observed were noted to be small and not clinically significant. Discussion: Our study although underpowered to show small differences does not support an association between dietary gluten/milk, IP, and behavioral changes in subjects with ASD.