Development of a Brief Parent-Report Screen for Common Gastrointestinal Disorders in Autism Spectrum Disorder

Autism spectrum disorders and the gastrointestinal tract: insights into mechanisms and clinical relevance

Autism spectrum disorders (ASDs) are recognized as central neurodevelopmental disorders diagnosed by impairments in social interactions, communication and repetitive behaviours. The recognition of ASD as a central nervous system (CNS)-mediated neurobehavioural disorder has led most of the research in ASD to be focused on the CNS. However, gastrointestinal function is also likely to be affected owing to the neural mechanistic nature of ASD and the nervous system in the gastrointestinal tract (enteric nervous system). Thus, it is unsurprising that gastrointestinal disorders, particularly constipation, diarrhoea and abdominal pain, are highly comorbid in individuals with ASD. Gastrointestinal problems have also been repeatedly associated with increased severity of the core symptoms diagnostic of ASD and other centrally mediated comorbid conditions, including psychiatric issues, irritability, rigid-compulsive behaviours and aggression. Despite the high prevalence of gastrointestinal dysfunction in ASD and its associated behavioural comorbidities, the specific links between these two conditions have not been clearly delineated, and current data linking ASD to gastrointestinal dysfunction have not been extensively reviewed. This Review outlines the established and emerging clinical and preclinical evidence that emphasizes the gut as a novel mechanistic and potential therapeutic target for individuals with ASD.

Faster Gastrointestinal Transit, Reduced Small Intestinal Smooth Muscle Tone and Dysmotility in the Nlgn3R451C Mouse Model of Autism

Individuals with autism often experience gastrointestinal issues but the cause is unknown. Many gene mutations that modify neuronal synapse function are associated with autism and therefore may impact the enteric nervous system that regulates gastrointestinal function. A missense mutation in the Nlgn3 gene encoding the cell adhesion protein Neuroligin-3 was identified in two brothers with autism who both experienced severe gastrointestinal dysfunction. Mice expressing this mutation (Nlgn3R451C mice) are a well-studied preclinical model of autism and show autism-relevant characteristics, including impaired social interaction and communication, as well as repetitive behaviour. We previously showed colonic dysmotility in response to GABAergic inhibition and increased myenteric neuronal numbers in the small intestine in Nlgn3R451C mice bred on a mixed genetic background. Here, we show that gut dysfunction is a persistent phenotype of the Nlgn3 R451C mutation in mice backcrossed onto a C57BL/6 background. We report that Nlgn3R451C mice show a 30.9% faster gastrointestinal transit (p = 0.0004) in vivo and have 6% longer small intestines (p = 0.04) compared to wild-types due to a reduction in smooth muscle tone. In Nlgn3R451C mice, we observed a decrease in resting jejunal diameter (proximal jejunum: 10.6% decrease, p = 0.02; mid: 9.8%, p = 0.04; distal: 11.5%, p = 0.009) and neurally regulated dysmotility as well as shorter durations of contractile complexes (mid: 25.6% reduction in duration, p = 0.009; distal: 30.5%, p = 0.004) in the ileum. In Nlgn3R451C mouse colons, short contractions were inhibited to a greater extent (57.2% by the GABAA antagonist, gabazine, compared to 40.6% in wild-type mice (p = 0.007). The inhibition of nitric oxide synthesis decreased the frequency of contractile complexes in the jejunum (WT p = 0.0006, Nlgn3R451C p = 0.002), but not the ileum, in both wild-type and Nlgn3R451C mice. These findings demonstrate that changes in enteric nervous system function contribute to gastrointestinal dysmotility in mice expressing the autism-associated R451C missense mutation in the Neuroligin-3 protein.

A Comparison of Family Management Between Families of Children With Autism Spectrum Disorder and Families of Children With Down Syndrome

INTRODUCTION

This cross-sectional study aimed to (1) compare family management between families of children with autism spectrum disorder (ASD) or Down syndrome and (2) evaluate the contribution of the child (ASD behaviors, feeding difficulties, sleep disturbances), caregiver (mental health) and family (social support) factors to the caregiver's perceived condition management ability and effort.

METHOD

Eighty-five caregivers (56 ASD, 29 Down syndrome) completed quantitative instruments online. Data analysis included independent samples t-tests and multiple linear regression.

RESULTS

There were no significant differences in the dimensions of family management between groups. More ASD behaviors were associated with lower condition management ability and higher condition management effort. Lower perceived social support and higher caregiver age were associated with lower condition management ability.

DISCUSSION

Integrating care into family life may be more challenging when the child has more social differences and behavioral rigidity. Nursing care should include an assessment of family social support.

Bidirectional relationship between internalizing symptoms and gastrointestinal problems in youth with Autism Spectrum Disorder

Many youth with autism spectrum disorder (ASD) experience co-occurring conditions, such as gastrointestinal (GI) problems and internalizing symptoms. However, the relationship among these co-occurring problems is not well-understood. We analyzed parent reports of GI problems and internalizing symptoms of 621 youth with ASD using path models in a structural equation modeling framework. The best-fitting model was a bidirectional model wherein internalizing symptoms, including withdrawn and anxious behavior, were correlated with GI problems, including constipation, diarrhea, nausea, and stomach pain. This study provides a better understanding of the relationship among co-occurring conditions in youth with ASD and should encourage clinicians to consider treatment of underlying internalizing symptoms or GI problems when providing services for individuals with ASD.

Relationship Between Gastrointestinal Symptoms in Autism Spectrum Disorder and Parent Stress, Anxiety, Depression, Quality of Life and Social Support

Gastrointestinal (GI) symptoms are a common comorbidity in children and adolescents with autism spectrum disorder (ASD). Little is known about the impact that GI symptoms have on parental well-being. Parents of 409 children and adolescents with ASD completed the GI Symptoms Inventory, Parenting Stress Index-Short Form, World Health Organization Quality of Life Abbreviated Version, Hospital Anxiety and Depression Scale, and the Multidimensional Scale of Perceived Social Support. High levels of stress were demonstrated by parents with 40.1% receiving clinically significant scores. A relationship was found between parental stress and GI symptoms. Parental anxiety and depression were found at high levels but were not more common in parents of individuals with GI symptoms than those without. Lower levels of quality of life were found in parents of individuals with GI symptoms compared to parents of individuals without GI symptoms. Parents of children with GI symptoms were less satisfied with their personal and social relationships with others. Parents of children with GI symptoms had lower scores on a measure of perceived social support than parents of children and adolescents without GI symptoms. GI symptoms are stressful for parents and future research is needed to determine how to alleviate this stress and to improve the quality of life of parents of individuals with ASD.

The Impact of Microbiota on the Gut-Brain Axis: Examining the Complex Interplay and Implications

The association and interaction between the central nervous system (CNS) and enteric nervous system (ENS) is well established. Essentially ENS is the second brain, as we call it. We tried to understand the structure and function, to throw light on the functional aspect of neurons, and address various disease manifestations. We summarized how various neurological disorders influence the gut via the enteric nervous system and/or bring anatomical or physiological changes in the enteric nervous system or the gut and vice versa. It is known that stress has an effect on Gastrointestinal (GI) motility and causes mucosal erosions. In our literature review, we found that stress can also affect sensory perception in the central nervous system. Interestingly, we found that mutations in the neurohormone, serotonin (5-HT), would result in dysfunctional organ development and further affect mood and behavior. We focused on the developmental aspects of neurons and cognition and their relation to nutritional absorption via the gastrointestinal tract, the development of neurodegenerative disorders in relation to the alteration in gut microbiota, and contrariwise associations between CNS disorders and ENS. This paper further summarizes the synergetic relation between gastrointestinal and neuropsychological manifestations and emphasizes the need to include behavioral therapies in management plans.

Gastrointestinal Dysfunction in Genetically Defined Neurodevelopmental Disorders

Gastrointestinal symptoms are common in most forms of neurodevelopment disorders (NDDs) such as in autism spectrum disorders (ASD). The current patient-reported outcome measures with validated questionnaires used in the general population of children without NDDS cannot be used in the autistic individuals. We explore here the multifactorial pathophysiology of ASD and the role of genetics and the environment in this disease spectrum and focus instead on possible diagnostics that could provide future objective insight into the connection of the gut-brain-microbiome in this disease entity. We provide our own data from both humans and a zebrafish model of ASD called Phelan-McDermid Syndrome. We hope that this review highlights the gaps in our current knowledge on many of these profound NDDs and that it provides a future framework upon which clinicians and researchers can build and network with other interested multidisciplinary specialties.

Prevalence of gastrointestinal symptoms among autistic individuals, with and without co-occurring intellectual disability

Gastrointestinal symptoms (GI) are very common among individuals on the autism spectrum. Prior research reports mixed findings regarding whether individuals with autism and co-occurring intellectual disability (ID) have elevated risk of gastrointestinal symptoms relative to individuals with autism alone. GI symptoms can be challenging to assess in individuals with autism spectrum disorder (ASD) and/or ID given challenges with language, communication, and interoception. Prior research has tended to only include individuals with documented presence or absence of GI symptoms or conditions, that is, to exclude observations in which there is uncertainty regarding presence of GI symptoms. Therefore, none of the prior autism studies reported the association between ID and the certainty regarding presence or absence of GI symptoms. The objective of this study was to examine differences in parental certainty and odds of reporting gastrointestinal signs and symptoms among children on the autism spectrum, with and without intellectual disability. Participants were 308 children (36% ID) with a clinical diagnosis of autism spectrum disorder (6-17 years). Parents endorsed whether their child had experienced or displayed a range of signs or symptoms related to GI problems in the past 3 months. Parents of autistic children with ID were less certain about the presence of more subjective symptoms, including abdominal pain, nausea, and bloating. Conversely, certainty regarding more objective signs (e.g., constipation, diarrhea, spitting up, etc.) was not significantly different. More accurate measures for GI signs/symptoms are needed for this population.

Questionnaire-based analysis of autism spectrum disorders and gastrointestinal symptoms in children and adolescents: a systematic review and meta-analysis

Background

Gastrointestinal (GI) symptoms are frequently experienced by children with autism spectrum disorder (ASD), and these symptoms cause difficulties for these children and their families. However, studies of GI symptom prevalence differ significantly. This meta-analysis aimed to analyze the prevalence of GI symptoms in children with ASD.

Methods and findings

PubMed, Scopus, Web of Science, EMBASE were electronically searched to collect all literature on gastrointestinal symptoms of children with ASD collected through questionnaires or scales from January 2012 to May 2021. Four researchers independently scanned the literature and extracted information on general characteristics. First author name, year of publication, geographical location, type of study, sample sizes of ASD and control (if any) children, sex and average age, number of GI cases, number of GI symptoms, GI assessment tools (gastrointestinal symptoms scale), autism diagnosis methods, and other necessary data were collected and analyzed using Stata V16. The questionnaires included the Rome, 6-GSI, GIQ, GSRS, GSIQ, ADI-R, PedsQL-GI, parent-report, GI-related, and self-administered questionnaires. Compared with typically developing (TD) children, the odds ratio for In children with ASD with at least one GI symptom was 3.64, and the total prevalence was 55%. The cumulative prevalence rates of various symptoms were summarized, showing that 37% of children with ASD had constipation, 21% had abdominal pain, 19% had diarrhea, 8% had vomiting, and 23% had abdominal distension.

Conclusions

The results of this meta-analysis on GI symptoms in ASD show that patients with ASD are more likely to develop symptoms than TD children. The prevalence of GI symptoms in In children with ASD was 55%.

Systematic Review Registration

www.crd.york.ac.uk/PROSPERO, identifier, #CRD42017080579.

Gastrointestinal Disorders and Food Selectivity: Relationship with Sleep and Challenging Behavior in Children with Autism Spectrum Disorder

The aim of this study was to evaluate the interaction between gastrointestinal (GI) disorders, sleep problems, and challenging behaviors in children with a diagnosis of Autism Spectrum Disorder (ASD) and their effect on parental stress. The secondary objective was to assess the frequency and type of GI and feeding disorders in a sample of children with ASD through a multidisciplinary assessment and, finally, to investigate families' perceptions and satisfaction with the proposed multidisciplinary approach. All children underwent a comprehensive gastroenterological and neuropsychiatric evaluation supported by standardized questionnaires. Pediatric gastroenterologists, specifically trained in Applied Behavior Analysis (ABA), provided advice for parent-delivered behavioral intervention for food selectivity. Thirty-six children with an autism diagnosis (29 males, age 4.5 +/-2.2 years, mean +/- SD) were enrolled. A positive correlation between sleep problems and aggressive behavior was found, and this association was stronger in children experiencing more problematic mealtime behaviors (b = 0.788, p = 0.014). Sleep difficulties were associated with stereotyped behaviors and parent-perceived stress. Parents interviewed about the gastroenterology visit perceived this multidisciplinary approach as helpful in addressing food selectivity. This study shows that sleep and mealtime issues can have a synergistic negative impact on ASD symptoms. A multidisciplinary approach and an integrated assessment of GI, feeding problems, and sleep disorders could be helpful in diagnosing comorbidities and to provide targeted advice to parents.

Understanding Challenging Behaviors in Autism Spectrum Disorder: A Multi-Component, Interdisciplinary Model

A multi-component, interdisciplinary model is described which explains the presence of, and in other cases the lack of, many challenging behaviors associated with autism spectrum disorder (ASD). More specifically, the model expands the operant behavioral conditioning paradigm by taking into account medical comorbidities and interoceptive processing.

Characteristics of the autism spectrum disorder gastrointestinal and related behaviors inventory in children

Gastrointestinal (GI) symptoms are one of the prevalent co‐occurring issues in autism spectrum disorder (ASD), though the range of symptom frequency estimates varies dramatically across studies, which can limit the further research of GI issues in ASD as well as potential treatment strategies. The wide range of prevalence estimates is partly due to the lack of standardized, validated measures of GI symptoms among people with ASD. The goal of this study was to (1) develop a measure, which included non‐verbal and mealtime behaviors, to assess for GI symptoms and (2) evaluate its psychometric characteristics. This was accomplished by drawing on two existing tools, Autism Treatment Network Gastrointestinal Inventory and the Brief Autism Mealtime Behavior Inventory, and deriving new items, to create the “ASD Gastrointestinal and Related Behaviors Inventory” (ASD‐GIRBI). The ASD‐GIRBI was piloted in an online registry of families with a child with ASD. A psychometric analysis was carried out in a sample of 334 children aged 6–17 years with ASD, resulting in a 36‐item tool. The Cronbach's alpha for the overall scale was 0.88. Exploratory factor analysis identified a seven‐factor model (1. Bowel movement pain; 2. Aggressive or disruptive during mealtimes; 3. Particular with foods; 4. Abdominal pain and upset stomach; 5. Refusing food; 6. Constipation and encopresis; 7. Motor or other behaviors). Following validation in an independent sample with clinical evaluation of GI symptoms, this tool will be helpful for both research and clinical purposes.

Gastrointestinal (GI) symptoms are common in children with autism spectrum disorder (ASD), yet assessing these symptoms remains challenging. This study developed a parent‐report, 36‐item questionnaire to measure GI symptoms in children with ASD. The tool included questions about food, mealtimes, GI symptoms, bowel habits, and behavior. This questionnaire may help researchers and clinicians assess GI symptoms among children with ASD.

A Personalized Multidisciplinary Approach to Evaluating and Treating Autism Spectrum Disorder

Autism Spectrum Disorder (ASD) is a complex neurodevelopmental disorder without a known cure. Current standard-of-care treatments focus on addressing core symptoms directly but have provided limited benefits. In many cases, individuals with ASD have abnormalities in multiple organs, including the brain, immune and gastrointestinal system, and multiple physiological systems including redox and metabolic systems. Additionally, multiple aspects of the environment can adversely affect children with ASD including the sensory environment, psychosocial stress, dietary limitations and exposures to allergens and toxicants. Although it is not clear whether these medical abnormalities and environmental factors are related to the etiology of ASD, there is evidence that many of these factors can modulate ASD symptoms, making them a potential treatment target for improving core and associated ASD-related symptoms and improving functional limitation. Additionally, addressing underlying biological disturbances that drive pathophysiology has the potential to be disease modifying. This article describes a systematic approach using clinical history and biomarkers to personalize medical treatment for children with ASD. This approach is medically comprehensive, making it attractive for a multidisciplinary approach. By concentrating on treatable conditions in ASD, it is possible to improve functional ability and quality of life, thus providing optimal outcomes.

Gastrointestinal concerns in children with autism spectrum disorder: A qualitative study of family experiences

LAY ABSTRACT

Gastrointestinal problems are common in the autism spectrum disorder community and may affect both the person with autism spectrum disorder and their families. However, little research is available on the experiences of families who have a child with both autism spectrum disorder and gastrointestinal symptoms. We held one-on-one interviews with 12 parents of children who had both autism spectrum disorder and gastrointestinal symptoms. We analyzed the raw text responses from these interviews and identified four main themes. First, parents shared that their children had trouble verbally communicating when they were experiencing gastrointestinal symptoms (Theme 1). This led parents to use bodily signs, such as changes in the stool, and non-verbal behaviors, such as irritability, to recognize when their child was having gastrointestinal symptoms. Next, gastrointestinal issues affected both the child's well-being and their ability to attend class and extracurricular or social activities (Theme 2). The gastrointestinal issues also affected the family's routines, overall well-being, and their ability to go out and do activities together as a family (Theme 3). Finally, parents often had challenges receiving accessible and quality healthcare for their child's gastrointestinal problems (Theme 4). Together, these findings highlight the enormous burden that gastrointestinal symptoms have on the wellness of children with autism spectrum disorder and their families.

Prevalence and Clinical Features of Celiac Disease in a Cohort of Italian Children with Autism Spectrum Disorders

Background: Autism spectrum disorders (ASD) are a heterogeneous group of neurodevelopmental conditions whose etiopathogenesis derives from a complex interaction between genetic liability and environmental factors. In this framework, mounting evidence suggests that immune system dysfunction could be a risk factor contributing to the development of ASD in at least a subpopulation of individuals. In particular, some studies suggest an association between celiac disease (CD)—a long-term autoimmune disorder that primarily affects the small intestine triggered by the ingestion of gluten—and ASD, while others hypothesized a random link. This investigation aimed to evaluate the prevalence of CD in a large sample of school-aged children with ASD and to characterize their clinical profile. Methods: Medical records of 405 children with ASD aged 5–11 years (mean age: 7.2 years; SD: 1.8 years) consecutively referred to a tertiary-care university hospital between January 2014 and December 2018 were reviewed; among them, 362 had carried out serological testing for CD. Results: Nine patients with positive CD serology were identified, eight of which satisfied the criteria for CD diagnosis. The estimated CD prevalence in ASD children was 2.18% (95% CI, 0.8–3.7), which was not statistically different (1.58%; p = 0.36) from that of an Italian population, matched for age range, considered as a control group (95% CI, 1.26–1.90). Three out of the eight ASD patients with CD did not have any symptoms suggestive of CD. Conclusions: Our findings did not show a higher prevalence of CD in ASD children than in the control population, but could suggest the utility of routine CD screening, given its frequent atypical clinical presentation in this population.

Analysis of the Nutrition, Self-Care Skills, and Health Professional Support in Schools of Children with Autism Spectrum Disorder

AIM

This study aimed to determine the nutrition, self-care skills, and health professional support of children with autism spectrum disorder.

METHOD

This is a descriptive and cross-sectional study. The parents of 82 children with autism spectrum disorder agreed to participate as part of a study group in 8 special education schools in 3 districts. The schools were selected on the basis of their levels of sociodemographic development. The data were collected and analysed between September 2016 and July 2017 using a two-section questionnaire developed after a literature review.

RESULTS

The majority of the parents (63.4%) had sufficient knowledge with regard to autism spectrum disorder, but the issues that were most lacking in terms of education were care, nutrition, and skills related to daily living (36.2%). The parents wanted to be educated on “nutrition problems,” and “activities of daily living.” The majority of the children lacked self-care skills (82.9%).

CONCLUSION

The most frequently observed nutrition problem in children with autism spectrum disorder was selective eating. In line with the literature, the majority of the children in this study were found to be unable to care for themselves. School nurses can provide support in terms of nutrition and self-care skills in these schools. School health education programmes for parents can be developed to allow for the more rapid and effective resolution of nutrition and self-care problems.

The Gut-Brain-Microbiome Axis and Its Link to Autism: Emerging Insights and the Potential of Zebrafish Models

Research involving autism spectrum disorder (ASD) most frequently focuses on its key diagnostic criteria: restricted interests and repetitive behaviors, altered sensory perception, and communication impairments. These core criteria, however, are often accompanied by numerous comorbidities, many of which result in severe negative impacts on quality of life, including seizures, epilepsy, sleep disturbance, hypotonia, and GI distress. While ASD is a clinically heterogeneous disorder, gastrointestinal (GI) distress is among the most prevalent co-occurring symptom complex, manifesting in upward of 70% of all individuals with ASD. Consistent with this high prevalence, over a dozen family foundations that represent genetically distinct, molecularly defined forms of ASD have identified GI symptoms as an understudied area with significant negative impacts on quality of life for both individuals and their caregivers. Moreover, GI symptoms are also correlated with more pronounced irritability, social withdrawal, stereotypy, hyperactivity, and sleep disturbances, suggesting that they may exacerbate the defining behavioral symptoms of ASD. Despite these facts (and to the detriment of the community), GI distress remains largely unaddressed by ASD research and is frequently regarded as a symptomatic outcome rather than a potential contributory factor to the behavioral symptoms. Allowing for examination of both ASD's impact on the central nervous system (CNS) as well as its impact on the GI tract and the associated microbiome, the zebrafish has recently emerged as a powerful tool to study ASD. This is in no small part due to the advantages zebrafish present as a model system: their precocious development, their small transparent larval form, and their parallels with humans in genetics and physiology. While ASD research centered on the CNS has leveraged these advantages, there has been a critical lack of GI-centric ASD research in zebrafish models, making a holistic view of the gut-brain-microbiome axis incomplete. Similarly, high-throughput ASD drug screens have recently been developed but primarily focus on CNS and behavioral impacts while potential GI impacts have not been investigated. In this review, we aim to explore the great promise of the zebrafish model for elucidating the roles of the gut-brain-microbiome axis in ASD.

Gastrointestinal Issues and Autism Spectrum Disorder

Gastrointestinal disorders are one of the most common medical conditions that are comorbid with autism spectrum disorders. These comorbidities can cause greater severity in autism spectrum disorder symptoms, other associated clinical manifestations, and lower quality of life if left untreated. Clinicians need to understand how these gastrointestinal issues present and apply effective therapies. Effective treatment of gastrointestinal problems in autism spectrum disorder may result in marked improvements in autism spectrum disorder behavioral outcomes. This article discusses the gastrointestinal disorders commonly associated with autism spectrum disorders, how they present, and studied risk factors.

Developmental-behavioral profiles in children with autism spectrum disorder and co-occurring gastrointestinal symptoms

Gastrointestinal (GI) symptoms are frequently reported in children with autism spectrum disorder (ASD). We evaluated the frequency and severity of GI symptoms in preschool-aged children with ASD compared to participants with typical development (TD). Our goal was to ascertain whether GI symptoms are associated with differences in sex or developmental and behavioral measures. Participants were between 2 and 3.5 years of age and included 255 children with ASD (184 males/71 females) and 129 age-matched TD controls (75 males/54 females). A parent interview was used to assess GI symptoms (abdominal pain, gaseousness/bloating, diarrhea, constipation, pain on stooling, vomiting, difficulty swallowing, blood in stool or in vomit). Children with GI symptoms in each diagnostic group were compared to children without GI symptoms on measures of developmental, behavioral, and adaptive functioning. GI symptoms were reported more frequently in children with ASD compared to the TD group (47.8% vs. 17.8%, respectively). Children with ASD were also more likely to experience multiple GI symptoms (30.6% vs. 5.4%). GI symptoms were equally common in males and females across both diagnostic groups. There were no statistically significant differences in developmental or adaptive measures based on presence of GI symptoms in either ASD or TD children. Co-occurring GI symptoms were, however, associated with increased self-injurious behaviors, restricted stereotyped behaviors, aggressive behaviors, sleep problems and attention problems in both ASD and TD children. In children with ASD, a higher number of GI symptoms was associated with an increase in self-injurious behaviors, somatic complaints, reduced sleep duration, and increased parasomnias. LAY SUMMARY: ASD is characterized by challenges in social communication and repetitive behaviors. But, people with autism have many other difficulties including gastrointestinal problems. Children with ASD were three times more likely to experience GI symptoms than typically developing peers. Increased GI symptoms are associated with increased problem behaviors such as sleep problems, self-injury, and body aches. Since GI symptoms are often treatable, it is important to recognize them as soon as possible. Both clinicians and parents should become more aware of the high occurrence of GI problems in autistic people. Autism Res 2020, 13: 1778-1789. © 2020 International Society for Autism Research and Wiley Periodicals LLC.

The AutGO Initiative: A Conceptual Framework for Developing Genetics-Outcomes Research Hypotheses

The increasing emphasis on translational approaches to complex neuropsychiatric and neurodevelopmental conditions research requires scientists from a broad range of disciplines to build dynamic collaborations when formulating hypotheses and framing study designs. The need to integrate the knowledge and perspectives not only from multiple scientific silos but also from the populations impacted by these conditions presents a significant challenge to researchers, particularly for a heterogeneous condition like autism. As one path toward addressing these challenges, we have previously introduced Autism Genetics Outcomes (AutGO), an initiative to support broad stakeholder partnerships and promote a new integrated concept called GO (i.e., research approaches that draw on both genetics and clinical outcomes perspectives). Herein, we developed a workflow for collecting stakeholders' feedback toward the development of a GO hypothesis. AutGO is an evolving initiative, and here we describe how its three essential components (conceptual framework, applicability, and implementation) have been developed. As a proof‐of‐concept, the AutGO team sought to demonstrate how a GO hypothesis could be developed using a semi‐structured literature review workflow. We also developed a prototype from published reports and formulated a GO hypothesis for autism. Rather than seeking community stakeholder input after a research project is conceptualized and designed, the developed conceptual framework demonstrates the feasibility of formulating scientific hypotheses by engaging stakeholders in retrospective semi‐structured literature reviews. The presented workflow, prototype, and discussed recommendations will bring awareness in the autism research community about the benefits of applying the GO approach in order to promote translational aspects in genetics research.

Lay Summary

We used a community‐based engagement approach to develop AutGO (Autism Genetics Outcomes), an initiative to establish stakeholder partnerships and to promote research approaches (we refer to as GO) that draw on both genetics and clinical outcomes perspectives. Specifically, we developed a conceptual framework that includes a literature review process for developing GO hypotheses and stakeholder feedback collection protocol. Our work will bring awareness in the autism research community about the benefits of integrating patient perspectives in genetics research. Autism Res 2020, 13: 1286–1299. © 2020 The Authors. Autism Research published by International Society for Autism Research published by Wiley Periodicals LLC.

Gastrointestinal issues and Autism Spectrum Disorder

Gastrointestinal disorders are one of the most common medical conditions that are comorbid with autism spectrum disorders. These comorbidities can cause greater severity in autism spectrum disorder symptoms, other associated clinical manifestations, and lower quality of life if left untreated. Clinicians need to understand how these gastrointestinal issues present and apply effective therapies. Effective treatment of gastrointestinal problems in autism spectrum disorder may result in marked improvements in autism spectrum disorder behavioral outcomes. This article discusses the gastrointestinal disorders commonly associated with autism spectrum disorders, how they present, and studied risk factors.

Autism Spectrum Disorder as a Brain-Gut-Microbiome Axis Disorder

While there are numerous medical comorbidities associated with ASD, gastrointestinal (GI) issues have a significant impact on quality of life for these individuals. Recent findings continue to support the relationship between the gut microbiome and both GI symptoms and behavior, but the heterogeneity within the autism spectrum requires in-depth clinical characterization of these clinical cohorts. Large, diverse, well-controlled studies in this area of research are still needed. Although there is still much to discover about the brain-gut-microbiome axis in ASD, microbially mediated therapies, specifically probiotics and fecal microbiota transplantation have shown promise in the treatment of GI symptoms in ASD, with potential benefit to the core behavioral symptoms of ASD as well. Future research and clinical trials must increasingly consider complex phenotypes in ASD in stratification of large datasets as well as in design of inclusion criteria for individual therapeutic interventions.

Novel aspects of enteric serotonergic signaling in health and brain-gut disease

Gastrointestinal (GI) comorbidities are common in individuals with mood and behavioral dysfunction. Similarly, patients with GI problems more commonly suffer from co-morbid psychiatric diagnoses. Although the central and enteric nervous systems (CNS and ENS, respectively) have largely been studied separately, there is emerging interest in factors that may contribute to disease states involving both systems. There is strong evidence to suggest that serotonin may be an important contributor to these brain-gut conditions. Serotonin has long been recognized for its critical functions in CNS development and function. The majority of the body's serotonin, however, is produced in the GI tract, where it plays key roles in ENS development and function. Further understanding of the specific impact that enteric serotonin has on brain-gut disease may lay the foundation for the creation of novel therapeutic targets. This review summarizes the current data focusing on the important roles that serotonin plays in ENS development and motility, with a focus on novel aspects of serotonergic signaling in medical conditions in which CNS and ENS co-morbidities are common, including autism spectrum disorders and depression.

Study on Aberrant Eating Behaviors, Food Intolerance, and Stereotyped Behaviors in Autism Spectrum Disorder

Objective: To investigate the aberrant eating behaviors (EBs), gastrointestinal (GI) symptoms, and food intolerance in children with autism spectrum disorder (ASD) and their association with clinical core symptoms of ASD. Method: A total of 94 preschool children with ASD treated at the Child Mental Health Research Center of Nanjing Brain Hospital between October 2016 and April 2018 were enrolled. In addition, 90 children with typical development (TD) in the community during the same period were recruited. The conditions of aberrant EBs and GI symptoms in children were investigated using questionnaire surveys. Serum specific IgG antibodies against 14 kinds of food were detected using enzyme-linked immunosorbent assays (ELISAs). Results: The detection rate of aberrant EBs in the ASD group was significantly higher than that in the TD group (67.39 vs. 34.94%), and the rate of GI symptoms was also higher in the ASD group than that in the TD group (80.22 vs. 42.11%). Detection of food intolerance in children with ASD showed that the positive rate was 89.89% and that the majority of children had multiple food intolerances. The correlation analysis results showed that the severity of aberrant EBs positively correlated with stereotyped behavior of children with ASD (r = 0.21, P = 0.04) and that food-specific IgG antibodies concentrations positively correlated with high-level stereotyped behavior in children with ASD (r = 0.23, P = 0.03). Conclusion: ASD with aberrant EBs or high food-specific IgG antibodies concentrations had more severe stereotyped behavior, which may have implications for exploring the immune mechanism of ASD. Clinical Trial Registration: ChiCTR-RPC-16008139.

A Descriptive Review on the Prevalence of Gastrointestinal Disturbances and Their Multiple Associations in Autism Spectrum Disorder

Background and Objectives: Gastrointestinal disturbances have been frequently, but not unanimously, reported in autism spectrum disorder (ASD) individuals. Thus, digestive symptoms, such as constipation, diarrhea, abdominal bloating, and pain have been reported to correlate to the various maladaptive behaviors in ASD children, such as irritability, social withdrawal, stereotypy, hyperactivity, and even language regression. In this context, the present study provides an overview on the prevalence of the gastrointestinal (GI) disorders in ASD and the correlation between these and ASD symptoms and comorbidities and subsequently discusses the metabolic and microbiome factors underlying the effects of GI disorders in ASD. Materials and Methods: For our analysis of GI symptoms in children with ASD, we have searched peer-reviewed journals from 2005 to 2017 in PubMed databases that addressed the specificity of GI symptoms in ASD and included correlations of GI and ASD symptoms. The criteria for inclusion were clear quantitative mentioning of GI modifications, GI symptoms correlation with specific ASD symptoms or comorbidities, an appropriate methodology for defining ASD, and larger size samples. For this topic, only studies on human patients and original research were considered. A subsequent search in PubMed databases in journals from 2000 to 2017 we analyzed 13 articles on the mechanisms underlying the impact of GI dysfunctions in ASD, including gut microbial dysbiosis, immune reactivity, genetics, and altered neurotransmitters on the gut-brain axis. Results: In the 18 original research studies that we selected out of an initial 327 studies, despite the different methodology, a predominant 83% highlighted the increased prevalence of GI symptoms in ASD patients. Constipation was most frequently cited, appearing in 12 of the studies (80%), followed by diarrhea reports in eight studies (53%). The association between cognitive and behavioral deficits and GI disorders was suggested in certain groups of ASD individuals. Conclusion: The evidence presented so far by numerous studies seems to indicate that GI dysfunctions are of particular relevance in ASD, underlined by various abnormalities along the nervous connections between the central nervous system and the gut, such as impaired parasympathetic activity and increased endocrine stress response. Sufficiently large size samples and standardized methodology are required for future studies to clarify the complex interactions between GI disturbances and ASD symptoms.

Vocal and motor behaviors as a possible expression of gastrointestinal problems in preschoolers with Autism Spectrum Disorder

Background

Gastrointestinal (GI) problems are one of the most frequent comorbidities in Autism Spectrum Disorder (ASD) but can be under-recognized due to the concomitant communication difficulties of this population. Accordingly, some associated behaviors (AB) such as verbal and motor behaviors (VB and MB, respectively) have been identified as a possible expression of an underlying GI problem and evaluated through an ad hoc questionnaire (the Associated Behaviors Questionnaire -ABQ-). The aims of this study were to investigate the presence and the type of AB in an Italian sample of ASD preschoolers, and to determine their correlations with GI problems.

Methods

We included 85 ASD preschoolers (mean age 4.14 years; SD 1.08) splitted into two groups (GI and No-GI) through the GI Severity Index instrument. AB were evaluated through the ABQ that includes VB, MB and Changes in overall state (C) clusters. Specific tools were administered to evaluate the ASD core ad associated symptoms, as well as the intellective and adaptive functioning.

Results

The GI group (N = 30) showed significantly higher scores in all the three ABQ areas (VB, MB and C) than the No-GI group (N = 55), with a positive correlation between GI symptoms and some specific AB as well as ABQ Total score. By dividing the whole sample in verbal and non-verbal individuals, both specific and shared AB emerged in the two groups.

Conclusions

Our results alert clinicians to consider behavioral manifestations as a possible expression of GI problems in ASD subjects. Therefore, the evaluation of AB may be useful to identify the presence of GI problems in the ASD populations, and especially in non-verbal ASD children.

Clustering of co-occurring conditions in autism spectrum disorder during early childhood: A retrospective analysis of medical claims data

Individuals with autism spectrum disorder (ASD) are frequently affected by co-occurring medical conditions (COCs), which vary in severity, age of onset, and pathophysiological characteristics. The presence of COCs contributes to significant heterogeneity in the clinical presentation of ASD between individuals and a better understanding of COCs may offer greater insight into the etiology of ASD in specific subgroups while also providing guidance for diagnostic and treatment protocols. This study retrospectively analyzed medical claims data from a private United States health plan between years 2000 and 2015 to investigate patterns of COC diagnoses in a cohort of 3,278 children with ASD throughout their first 5 years of enrollment compared to 279,693 children from the general population without ASD diagnoses (POP cohort). Three subgroups of children with ASD were identified by k-means clustering using these COC patterns. The first cluster was characterized by generally high rates of COC diagnosis and comprised 23.7% (n = 776) of the cohort. Diagnoses of developmental delays were dominant in the second cluster containing 26.5% (n = 870) of the cohort. Children in the third cluster, making up 49.8% (n = 1,632) of the cohort, had the lowest rates of COC diagnosis, which were slightly higher than rates observed in the POP cohort. A secondary analysis using these data found that gastrointestinal and immune disorders showed similar longitudinal patterns of prevalence, as did seizure and sleep disorders. These findings may help to better inform the development of diagnostic workup and treatment protocols for COCs in children with ASD. Autism Res 2019, 12: 1272-1285. © 2019 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: Medical conditions that co-occur with autism spectrum disorder (ASD) vary significantly from person to person. This study analyzed patterns in diagnosis of co-occurring conditions from medical claims data and observed three subtypes of children with ASD. These results may aid with screening for co-occurring conditions in children with ASD and with understanding ASD subtypes.

The Relationship Among Gastrointestinal Symptoms, Problem Behaviors, and Internalizing Symptoms in Children and Adolescents With Autism Spectrum Disorder

Background: Many individuals with autism spectrum disorder (ASD) have co-occurring gastrointestinal (GI) symptoms, but the etiology is poorly understood. These GI symptoms often coincide with problem behaviors and internalizing symptoms, which reduces the quality of life for these individuals. Methods: This study examined the relationships among GI problems, problem behaviors, and internalizing symptoms in a sample of 340 children and adolescents with ASD who are patients at the University of Missouri Thompson Center for Autism & Neurodevelopmental Disorders. Results: The majority of patients experienced constipation (65%), about half experienced stomachaches or stomach pain (47.9%), and others experienced nausea (23.2%) or diarrhea (29.7%). Young children with aggressive problem behaviors were 11.2% more likely to have co-occurring nausea; whereas, older children showed more complex relationships between internalizing symptoms and GI symptoms. Older children with greater anxiety symptoms were 11% more likely to experience constipation, but 9% less likely to experience stomachaches. Older children with greater withdrawn behavior were 10.9% more likely to experience stomachaches, but 8.7% less likely to experience constipation. Older children with greater somatic complaints were 11.4% more likely to experience nausea and 11.5% more likely to experience stomachaches. Conclusions: Results suggest that the presentation of externalizing problem behavior and internalizing symptoms associated with GI problems differs between young children and older children with ASD. Therefore, behavior may have different relationships with GI symptoms at different ages, which may have implications for the treatment of and clinical approach to GI disturbances in ASD.

Lack of Associations Between Dietary Intake and Gastrointestinal Symptoms in Autism Spectrum Disorder

Background: Many individuals with autism spectrum disorder (ASD) have significant gastrointestinal (GI) symptoms, but their etiology is currently unknown. Dietary interventions are common in children and adolescents with ASD, including diets with increased omega-3 fatty acids or diets free of gluten and/or casein, which may also impact GI symptoms and nutrition. However, little is known about the relationship between nutritional intake and GI symptomatology in ASD. The objective of this study was to assess the relationships between GI symptoms, omega-3 intake, micronutrients, and macronutrients in children with ASD. Methods: A total of 120 children diagnosed with ASD participated in this multisite study. A food frequency questionnaire was completed by the patient's caretaker. The USDA Food Composition Database was utilized to provide nutritional data for the food items consumed by each participant. GI symptomatology was assessed using a validated questionnaire on pediatric gastrointestinal symptoms. Results: There were no significant associations between GI symptoms and the amount of omega-3 fatty acids and/or other micro- and macronutrients contained in the diet. Conclusions: This study suggests that dietary variations do not appear to drive GI symptoms, nor do GI symptoms drive dietary variations in those with ASD, although causation cannot be determined with this observational assessment. Furthermore, there may be other factors associated with lower GI tract symptoms in ASD, such as increased stress response.