Indications

• Autism spectrum disorder

• Bowel problems

• Conditions that might affect behavior and mental wellbeing

• Food allergies

Overview

Several problems can arise when food is not digested (metabolised) properly and/or allowed to leave the gut in an incompletely digested form.

This test might indicate problems with one or both elements: gut permeability (often called the leaky gut) and the presence of dietary-derived peptides (potentially indicative of poor digestion of certain foods).

Drawing on our published work in autism spectrum conditions, we look for the presence of two sets of compounds:

• IAG (trans-indolyl-3-acryloylglycine): a metabolite of the amino acid tryptophan. Tryptophan is normally the starting point for several important compounds include serotonin (linked to mood) and melatonin (linked to the sleep-wake cycle). One of the more obscure routes for the metabolism of tryptophan is thought to end with the production of IAG. IAG is speculated to be a detoxified endpoint of other compounds whose primary effect might be to disrupt various biological membranes throughout the body. This effect may extend to leaky gut.

 • Dietary-derived peptides: compounds produced as food proteins are digested into their constituent amino acids. Short chains of these amino acids have various chemical activities depending on what amino acids are included. This test looks for the presence of several peptides derived from gluten and casein.

Evidence is accumulating on a role for dietary intervention excluding gluten and/or casein as a possible intervention option for some people with an autism spectrum or related developmental condition.

Practical

Specimen requirements:

Urine

Average processing time:

10 ±4 days

Research

• Anderson RJ, Bendell DJ, Garnett I, Groundwater PW, Lough WJ, Mills MJ, Savery D, Shattock PE: Identification of indolyl-3-acryloylglycine in the urine of people with autism. J Pharm Pharmacol. 2002 Feb;54(2):295-8.

• Bressan P, Kramer P. Bread and Other Edible Agents of Mental Disease. Frontiers in Human Neuroscience. 2016;10:130.

• Bull G, Shattock P, Whiteley P, Anderson R, Groundwater PW, Lough JW, Lees G: Indolyl-3-acryloylglycine (IAG) is a putative diagnostic urinary marker for autism spectrum disorders. Med Sci Monit. 2003 Oct;9(10):CR422-5.

• Fiorentino M, Sapone A, Senger S, Camhi SS, Kadzielski SM, Buie TM, Kelly DL, Cascella N, Fasano A. Blood–brain barrier and intestinal epithelial barrier alterations in autism spectrum disorders. Molecular Autism. 2016;7(1).

• Genuis S, Bouchard T. Celiac Disease Presenting as Autism. Journal of Child Neurology. 2009;25(1):114-119.

• Ghalichi F, Ghaemmaghami J, Malek A, Ostadrahimi A. Effect of gluten free diet on gastrointestinal and behavioral indices for children with autism spectrum disorders: a randomized clinical trial. World Journal of Pediatrics. 2016;12(4):436-442.

• Knivsberg A, Reichelt K, HØien T, NØdland M. A Randomised, Controlled Study of Dietary Intervention in Autistic Syndromes. Nutritional Neuroscience. 2002;5(4):251-261.
• Pedersen L, Parlar S, Kvist K, Whiteley P, Shattock P. Data mining the ScanBrit study of a gluten- and casein-free dietary intervention for children with autism spectrum disorders: Behavioural and psychometric measures of dietary response. Nutritional Neuroscience. 2013;17(5):207-213.

• Pennesi, C. M., & Klein, L. C. (2012). Effectiveness of the gluten-free, casein-free diet for children diagnosed with autism spectrum disorder: Based on parental report. Nutritional Neuroscience, 15(2), 85-91.

• Saeed DU, Ishaq DM, Zil-E-Ali DA, Zafar DH, Zafar S. Peptides, Gluten, Casein And Autistic Behavior – A Review. The Professional Medical Journal. 2016;23(07):766-769.

• Whiteley P, Shattock P, Carr K, Hooper M, Todd L. How Could a Gluten- and Casein-Free Diet Ameliorate Symptoms Associated with Autism Spectrum Conditions? Autism Insights 2010:2 39–53.
• Whiteley P, Shattock P, Knivsberg A-M, et al. Gluten- and casein-free dietary intervention for autism spectrum conditions. Frontiers in Human Neuroscience. 2012;6:344.