Slow intestinal transit contributes to elevate urinary p-cresol level in Italian autistic children.

Abstract

The uremic toxin p-cresol (4-methylphenol) is either of environmental origin or can be synthetized from tyrosine by cresol-producing bacteria present in the gut lumen. Elevated p-cresol amounts have been previously found in the urines of Italian and French autism spectrum disorder (ASD) children up until 8 years of age, and may be associated with autism severity or with the intensity of abnormal behaviors. This study aims to investigate the mechanism producing elevated urinary p-cresol in ASD. Urinary p-cresol levels were thus measured by High Performance Liquid Chromatography in a sample of 53 Italian ASD children assessed for (a) presence of Clostridium spp. strains in the gut by means of an in vitro fecal stool test and of Clostridium difficile-derived toxin A/B in the feces, (b) intestinal permeability using the lactulose/mannitol (LA/MA) test, (c) frequent use of antibiotics due to recurrent infections during the first 2 years of postnatal life, and (d) stool habits with the Bristol Stool Form Scale. Chronic constipation was the only variable significantly associated with total urinary p-cresol concentration (P < 0.05). No association was found with presence of Clostridium spp. in the gut flora (P = 0.92), augmented intestinal permeability (P = 0.18), or frequent use of antibiotics in early infancy (P = 0.47). No ASD child was found to carry C. difficile in the gut or to release toxin A/B in the feces. In conclusion, urinary p-cresol levels are elevated in young ASD children with increased intestinal transit time and chronic constipation. Autism Res 2016, 9: 752-759. © 2015 International Society for Autism Research, Wiley Periodicals, Inc.

• Authors: Stefano Gabriele, Roberto Sacco, Laura Altieri, Cristina Neri, Andrea Urbani, Carmela Bravaccio, Maria Pia Riccio, Maria Rosaria Iovene, Francesca Bombace, Laura De Magistris, Antonio M Persico
• Journal: Autism research : official journal of the International Society for Autism Research (Autism Res) Vol. 9 Issue 7 Pg. 752-9 (07 2016) ISSN: 1939-3806 [Electronic] United States
• PMID: 26437875 (Publication Type: Journal Article)
• Copyright: © 2015 International Society for Autism Research, Wiley Periodicals, Inc.

Chemical References

• Cresols
• 4-cresol

Topics

• Autism Spectrum Disorder (physiopathology)
• Autistic Disorder
• Child
• Cresols (urine)
• Feces
• Gastrointestinal Transit
• Humans