Is food refusal in autistic children related to TAS2R38 genotype?

Several studies suggest that atypical eating behaviors, in particular food selectivity, are more frequent in children with autism spectrum disorder (ASD). A link between bitter taste perception, namely PROP/PTC sensitivity and food preferences is known in healthy children. The aim of this study is to investigate whether genetic variants of the TAS2R38 taste receptor responsible for different bitter sensitivity could affect foods preferences and consequently food refusal in ASD children. We recruited 43 children with ASD and 41 with normotypic development (TD) with or without food selectivity, aged between 2 and 11 years. Children were characterized for bitter sensitivity by means of PROP strips and FACS analysis and genotyped for TAS2R38 polymorphisms. Food selectivity was assessed by a validated food preference questionnaire filled by parents. A statistically significant correlation between PROP sensitivity and food refusal was observed. Furthermore, a prevalence of the PAV-sensitive haplotype compared to the AVI-insensitive one was seen in ASD children with food selectivity. In agreement with the initial hypothesis the results show that food refusal in ASD children is mediated by bitter taste sensitivity thus suggesting that the bitter sensitivity test may be used as a device to orientate tailored food proposals for the practical management of food selectivity in ASD. Autism Res 2018, 11: 531-538. © 2017 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: A variation of the gene TAS2R38, associated with bitter taste sensitivity, can cause a different perception of some foods. In particular, some children are hypersensitive to bitterness and show a more restricted repertoire of accepted foods. We evaluate bitter sensitivity in ASD children with or without food selectivity, through a simple bitter taste test with edible strips. The results show that food refusal in ASD children can be mediated by bitter taste sensitivity thus suggesting that the bitter sensitivity test may be used as a device to orientate tailored food proposals for the practical management of food selectivity in ASD.

Intestinal Dysbiosis and Yeast Isolation in Stool of Subjects with Autism Spectrum Disorders.

High frequency of gastrointestinal yeast presence in ASD subjects was shown through a simple cultural approach (Candida spp. in 57.5 % of ASDs and no controls); the identification of aggressive form (pseudo-hyphae presenting) of Candida spp. at light microscope means that adhesion to intestinal mucosa is facilitated. Dysbiosis appears sustained by lowered Lactobacillus spp. and decreased number of Clostridium spp. Absence of C. difficilis and its toxins in both ASDs and controls is also shown. Low-mild gut inflammation and augmented intestinal permeability were demonstrated together with the presence of GI symptoms. Significant linear correlation was found between disease severity (CARs score) and calprotectin and Clostridium spp. presence. Also GI symptoms, such as constipation and alternating bowel, did correlate (multivariate analyses) with the increased permeability to lactulose. The present data provide rationale basis to a possible specific therapeutic intervention in restoring gut homeostasis in ASDs.

Prevalence and titre of antibodies to cytomegalovirus and epstein-barr virus in patients with autism spectrum disorder.

BACKGROUND/AIM: The etiology of autism spectrum disorders (ASD) is currently unknown. Few studies have explored the role of Cytomegalovirus (CMV) and Epstein Barr Virus (EBV) as potential etiological factors of ASD. The aim of the present study was to evaluate the seropositivity rate and antibody titre to CMV and EBV in children with ASD compared to same-aged healthy controls. PATIENTS AND METHODS: We compared the seropositivity rate and titre of antibodies to CMV and EBV in 54 children with ASD (19 with autistic disorder and 35 with non-autistic disorder ASD) and in 46 controls. RESULTS: Seropositivity rate and titre of the two antibodies were not dissimilar between cases and controls. However, considering only patients with ASD, those seropositive for CMV tended to test worse to the major severity scales than the seronegative ones. CONCLUSION: Titre and seropositivity rate of antibodies to CMV and EBV are similar between children with ASD and healthy controls.

Exposure to Varicella Zoster Virus is higher in children with autism spectrum disorder than in healthy controls. Results from a case-control study.

BACKGROUND/AIM: Autism spectrum disorder (ASD) is a group of central nervous system disorders lacking a definite etiology. The aim of the present study was to compare the exposure rate and titer of antibodies to Varicella Zoster Virus (VZV) in children with ASD and in healthy controls. PATIENTS AND METHODS: We enrolled 54 children with ASD and 46 control individuals. RESULTS: The exposure rate and titer of anti-VZV antibodies were significantly higher in children with ASD compared to controls (59% vs. 39% and 694 mIU/ml vs. 94 mIU/ml, respectively). CONCLUSION: In the present case-control study, exposure to VZV was found to be independently associated with ASD.

Prevalence of herpes simplex virus 1 and 2 antibodies in patients with autism spectrum disorders.

BACKGROUND/AIM: The etiology of autism spectrum disorder (ASD) is unknown, even though it is hypothesized that a viral infection could trigger this disorder. The aim of this study was to evaluate the seropositivity rate and antibody level of Herpes Simplex Virus 1 (HSV1) and Herpes Simplex Virus 2 (HSV2) in children with ASD compared to same-aged healthy controls. PATIENTS AND METHODS: We compared seropositivity rate and levels of antibodies to HSV1/2 in 54 children with ASD (19 with autistic disorder and 35 with non-autistic ASD) and in 46 controls. RESULTS: Seropositivity rate and levels of anti-HSV1/2 were not dissimilar between cases and controls. Exposure to HSV2 was minimal. CONCLUSION: Rate of contact with HSV1 and HSV2 assessed by the mean of detection of specific antibodies was similar between children with ASD and healthy controls.