New Evidence Supports the Link Between Autism and Gastrointestinal Issues

There is a significant association between autism and gastrointestinal issues, as adults with higher autism scores have a higher prevalence of irritable bowel syndrome (IBS), food allergies, pain, and fatigue. These findings, published in Autism, have clinical implications for diagnosing, monitoring, and treating somatic problems of gastrointestinal disorders among adults with autism spectrum disorder (ASD).  

Although somatic problems like IBS, pain, and fatigue are somewhat common in children with ASD, relatively less is known about somatic problems in adults with ASD. The objective of the current study was to investigate the association between symptoms of autism and gastrointestinal issues, food allergies, musculoskeletal pain, and fatigue among a cohort of adults.

Researchers used data from the Lifelines Cohort Study – a prospective, population-based cohort study that examines the health and health-related behaviors of 167,729 persons living in the Netherlands. The researchers recruited adult participants aged 18 to 90 years between 2006 and 2013 and followed them until 2019. All participants completed the Adult Social Behavior Questionnaire (ASBQ), which measures symptoms of ASD, and the researchers used both continuous scores and standardized Z-score distributions in the analyses. Additionally, IBS was assessed using the Rome III IBS Diagnostic Questionnaire, pain was measured using the Widespread Pain Index (WPI) index, fatigue was assessed using the Checklist Individual Strength questionnaire, and food allergies were measured using survey questions.

A total of 35,048 adults completed the ASBQ and were included for analysis. The mean (SD) age of the participants was 49.5 (12.5) years, 41.8% were men, and 1.2% qualified for probable ASD, based on ASBQ scores. Men had higher autism symptom scores (mean=12.7) relative to women (mean=9.6), while women had a higher prevalence of IBS (5.7%), food allergy (9.5%), and higher scores of pain (mean=0.15) and fatigue (mean=2.70) compared with men (2.6%; 4.9%; 0.10; and 2.51, respectively).

In regression analyses, the researchers found that higher ASBQ scores were associated with a greater burden of somatic problems. Each unit increase in ASBQ scores was associated with significantly higher odds of experience IBS (odds ratio [OR], 1.44; 95% CI, 1.34-1.55) and food allergy (OR, 1.13; 95% CI, 1.07-1.20). Further, each unit increase in ASBQ scores was associated with 0.20 (95% CI, 0.18-0.22) and 0.37 (95% CI, 0.35-0.39) unit increase in pain and fatigue, respectively.

The researchers also found that age significantly moderated these associations, as younger age was associated with more severe somatic problems across all categories.

These findings demonstrate a significant association between symptoms of autism and gastrointestinal issues, pain, and fatigue. “If unnoticed or neglected, these risks could result in long-term detrimental impacts on health and quality of life over the lifespan,” the researchers concluded.

These study findings may be limited by the reliance on self-reported measures and the inability to establish causal relationships due to cross-sectional study design.

This article originally appeared on Psychiatry Advisor