Intestinal permeability (IPT) was investigated in patients with autism as well as in their first-degree relatives to investigate leaky gut hypothesis. Faecal calprotectin (FC) was also measured in patients with autism, either with or without gastrointestinal symptoms, and in their first-degree relatives.
IPT results, assessed by means of the lactulose/mannitol test, were compared with adult and child controls and with FC values.
A high percentage of abnormal IPT values were found among patients with autism (36.7%) and their relatives (21.2%) compared with normal subjects (4.8%). Patients with autism on a reported gluten-casein–free diet had significantly lower IPT values compared with those who were on an unrestricted diet and controls. Gastrointestinal symptoms were present in 46.7% of children with autism: constipation (45.5%), diarrhoea (34.1%), and others (alternating diarrhoea/constipation, abdominal pain, etc: 15.9%). FC was elevated in 24.4% of patients with autism and in 11.6% of their relatives; it was not, however, correlated with abnormal IPT values.
The results obtained support the leaky gut hypothesis and indicate that measuring IPT could help to identify a subgroup of patients with autism who could benefit from a gluten-free diet. The IPT alterations found in first-degree relatives suggest the presence of an intestinal (tight-junction linked) hereditary factor in the families of subjects with autism.
*Department Magrassi-Lanzara, Gastroenterology, Italy
†Department of Psychiatry, Neuropsychiatry, Dermatovenereology, Italy
‡Department of Experimental Medicine, Italy
§Department of Laboratory Medicine, Second University of Naples, Italy
||Department of Paediatrics, Federico II University of Naples, Italy
¶Clinica Pediatrica “B Trambusti,” University of Bari, Italy
#Fondazione Istituto Antoniano, Naples, Italy.
Received 11 November, 2009
Accepted 9 March, 2010
Address correspondence and reprint requests to Laura de Magistris, PhD, Second University of Naples, Department Magrassi-Lanzara, Gastroenterology, Piazza Miraglia 1-80132 Napoli, Italy (e-mail: email@example.com).
This research was supported in part with a grant from the Department Magrassi-Lanzara, Second University of Naples, Italy.
The present research was presented in poster form at Digestive Disease Week 2007 and 2008.
The authors report no conflicts of interest.