Urinary opioid peptides in children with autism spectrum disorders. A Pilot Study

BACKGROUND: Circulating β-casomorphins (BCM) and gluten exorphins (GE), which are exogenous opioid peptides originating from bovine milk protein casein and cereal protein gluten, respectively, have been proposed as potential trigger factor to symptoms observed in children with autism. OBJECTIVE: Given the debate surrounding the detectability of these opioid peptides in body fluids, particularly using highly sensitive and specific mass spectrometry (HPLC-MS) techniques, we aimed to investigate their presence in urine samples of autistic subjects. METHODS: We employed an HPLC-MS method for peptide detection. RESULTS: The presence of several BCMs and GEs in the urine of both autistic children (ASD) and healthy controls (HC) was documented. The detection of dietary opioid peptides even at very low concentrations underscores the sensitivity of this novel HPLC-MS method. BCM-8 was more often detected in the ASD group compared to the HC group. A higher prevalence of gastrointestinal (GI) symptoms were also observed in the ASD group. CONCLUSIONS: This pilot study supports the presence of BCMs and GEs in urine samples in subjects with autism as well as healthy controls which was the main goal of this pilot study. Prolonged exposure to bovine BCMs and GEs may play a role in the manifestation of core and GI symptoms in subgroups of autism. Further research is warranted to investigate this phenomenon thoroughly.