Environmental Factors Associated with Autism Spectrum Disorder: A Clinical Study of Microflora and Micronutrient Abnormalities

Daniel K Goyal

Research output: ThesisDoctoral Thesis


Abstract Daniel Kumar Goyal University of Manchester PhD Candidate in Neurosciences “Environmental Factors Associated with Autism: a Clinical Study of Microflora and Micronutrient Abnormalities” 19th October 2015 Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder characterised by impaired socialisation. The current project examines the hypothesis that ASD represents a broad range of distinct disease processes typified by environmental insult during a period crucial for the development of social integration skills, sharing simply the fundamental disruption to social functioning with various, definable systemic pathologies related to the initial insult conferring the heterogeneity of the condition. ASD will therefore have both modifiable environmental factors relating to the aetio-pathogenesis of the disease and also tangible remediable disease processes. Following an examination of the relevant literature this project presents the Variable Insult Model of Autism. As part of a wider research strategy, this project goes on to explore potential modifiable environmental factors in patients with ASD. Zinc deficiency was explored as a potential environmental modifiable factor involved in the pathophysiology of autism and co-morbid disease. 72 patients with ASD were compared with 234 non-ASD controls. Mean serum zinc levels in the ASD group vs. the control group were 10.01 umol/l (SD 1.52 umol/l) vs. 11.61 umol/l (SD 2.14 umol/l, with a statistically significant difference - p <0.0001, CI 1.2 – 2.1). The findings withstood correction for age and sex, and zinc did not correlate with diet or supplement use in the ASD group. Total lymphocyte count increased as zinc increased in the ASD group with zinc levels of 10.5 umol/l or above, suggesting zinc status is poor in patients with autism and this is affecting immune function. Urinary metabolomics, quantitative PCR stool analysis and autonomic function were also explored in ASD, as biomarkers of systemic disease processes presenting potential modifiable factors. The urinary organic acids of 49 patients were analysed versus population norms. 90% of patients with ASD had at least one abnormality. A follow-up study of 122 patients revealed succinic acid and 2-hydroxyhippuric acid were significantly raised in the ASD group versus population means (p = <0.0001 and
Original languageEnglish
Awarding Institution
  • University of Manchester
Publication statusPublished - 27 Nov 2015


  • Environmental Factors
  • Microflora
  • Zinc
  • Variable Insult Hypothesis
  • Neuroimmune
  • Prevention
  • Co-morbidity


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