Information on biological interventions, Autism and Aspergers syndreome - common Autism Spectrum Disorders


Digestive enzymes

Digestive enzymes are enzymes in the alimentary tract with a purpose of breaking down components of food so that they can be taken up by the organism. The main sites of action are the oral cavity, the stomach, the duodenum and the jejunum. They are secreted by different glands: the salivary glands, the glands in the stomach, the pancreas, and the glands in the small intestines.


No rigorous scientific studies have shown benefit in treating Autism Spectrum Disorders with the administration of digestive enzymes. A clinical trial did report that around 15% of subjects experienced significant side-effects form using digestive enzymes as a treatment (Brudnak, Rimland, & Kerry 2002).



Secretin is a peptide hormone secreted by the small intestine, and was the first hormone discovered. Secretin stimulates the secretion of bicarbonate from the liver, pancreas, and duodenal Brunner's glands in order to buffer the incoming protons of the acidic chyme. It also enhances the effects of cholecystokinin. It is known to promote the normal growth and maintenance of the pancreas.


It also reduces acid secretion from the stomach by inhibiting gastrin release from G cells. This helps neutralize the pH of the digestive products entering the duodenum from the stomach, as digestive enzymes from the pancreas (eg, pancreatic amylase and pancreatic lipase) function optimally at neutral pH.

There have been reports of dramatic reductions in symptoms of children on the autism spectrum following treatment with secretin. However, several clinical trials have failed to demonstrate any benefit from secretin compared to using a placebo (Williams, Wray, & Wheeler 2005).


Other studies have concluded that Secretin, Fenfluramine, Naltrexone and Adrenocorticotrophin have been demonstrated to be ineffective and/or harmful for children and adolescents with Autism. (Perry & Condillac 2003).


Shut this fact sheet on  Secretin and digestive enzymes as biomedical interventions for Autism

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Digestive enzymes and secretin are biomedical interventions that are supported by anecdotal from some parents of autistic children, but are not established as evidence-based interventions by rigorous research.