Gastrointestinal disease in children with autism spectrum disorders: Etiology or consequence?

Emerging Treatments and Therapies for Autism Spectrum Disorder: A Narrative Review

The prevalence of autism spectrum disorder (ASD) has increased over the last decade. In this regard, many emerging therapies have been described as ASD therapies. Although ASD does not have a cure, there are several management options available that can help reduce symptom severity. ASD is highly variable and, therefore, standard treatment protocols and studies are challenging to perform. Many of these therapies also address comorbidities for which patients with ASD have an increased risk. These concurrent diagnoses can include psychiatric and neurological disorders, including attention deficit and hyperactivity disorder, anxiety disorders, and epilepsy, as well as gastrointestinal symptoms such as chronic constipation and diarrhea. Both the extensive list of ASD-associated disorders and adverse effects from commonly prescribed medications for patients with ASD can impact presenting symptomatology. It is important to keep these potential interactions in mind when considering additional drug treatments or complementary therapies. This review addresses current literature involving novel pharmacological treatments such as oxytocin, bumetanide, acetylcholinesterase inhibitors, and memantine. It also discusses additional therapies such as diet intervention, acupuncture, music therapy, melatonin, and the use of technology to aid education. Notably, several of these therapies require more long-term research to determine efficacy in specific ASD groups within this patient population.

Autism in patients with eosinophilic gastrointestinal disease: A systematic review with meta-analysis

PURPOSE

Neurodevelopmental disorders, such as autism spectrum disorder (ASD), have been increasingly associated with eosinophilic gastrointestinal disorders (EGID). However, the relationship between these diseases remains unclear. We performed a systematic review with meta-analysis to address this issue.

METHODS

The search was performed according to the PRISMA guidelines using descriptors for ASD and EGIDs from the MEDLINE, Embase, PsycInfo, LILACS, and Web of Science databases. Observational studies with the prevalence of ASD in any EGID were included. The study protocol was registered on the PROSPERO platform under the number CRD42023455177.

RESULTS

The total dataset comprised 766,082 participants. The result of the single-arm meta-analysis showed an overall prevalence of ASD in the population with EGID of 21.59% (95% CI: 10.73-38.67). There was an association between EGID and ASD (OR: 3.44; 95% CI: 1.25-2.21), also significant when restricted only to EoE (OR: 3.70; 95% CI: 2.71-5.70).

DISCUSSION

Recent studies have implicated the influence of an inadequate epithelial barrier integrity in the pathogenesis of several diseases. The role of this mechanism can be extended to situations beyond allergic reactions, including other conditions with underlying immunological mechanisms. Several diseases are potentially related to the systemic effect of bacterial translocation in tissues with defective epithelial barriers.

CONCLUSION

Our meta-analysis provides evidence that supports the consideration of EGID in patients with ASD and ASD in patients with EGID. Despite its limitations, the results should also be validated by future studies, preferably using multicenter prospective designs in populations with low referral bias.

A Review of the Nutritional Approach and the Role of Dietary Components in Children with Autism Spectrum Disorders in Light of the Latest Scientific Research

Autism spectrum disorder (ASD) is a neurodevelopmental disorder that affects several areas of mental development. The onset of ASD occurs in the first few years of life, usually before the age of 3 years. Proper nutrition is important to ensure that an individual's nutrient and energy requirements are met, and it can also have a moderating effect on the progression of the disorder. A systematic database search was conducted as a narrative review to determine whether nutrition and specific diets can potentially alter gastrointestinal symptoms and neurobehavioral disorders. Databases such as Science Direct, PubMed, Scopus, Web of Science (WoS), and Google Scholar were searched to find studies published between 2000 and September 2023 on the relationship between ASD, dietary approaches, and the role of dietary components. The review may indicate that despite extensive research into dietary interventions, there is a general lack of conclusive scientific data about the effect of therapeutic diets on ASD; therefore, no definitive recommendation can be made for any specific nutritional therapy as a standard treatment for ASD. An individualized dietary approach and the dietician's role in the therapeutic team are very important elements of every therapy. Parents and caregivers should work with nutrition specialists, such as registered dietitians or healthcare providers, to design meal plans for autistic individuals, especially those who would like to implement an elimination diet.

Microbiome-Gut-Mucosal-Immune-Brain Axis and Autism Spectrum Disorder (ASD): A Novel Proposal of the Role of the Gut Microbiome in ASD Aetiology

Autism Spectrum Disorder (ASD) is a complex neurodevelopmental disorder characterised by deficits in social interaction and communication, as well as restricted and stereotyped interests. Due of the high prevalence of gastrointestinal disorders in individuals with ASD, researchers have investigated the gut microbiota as a potential contributor to its aetiology. The relationship between the microbiome, gut, and brain (microbiome-gut-brain axis) has been acknowledged as a key factor in modulating brain function and social behaviour, but its connection to the aetiology of ASD is not well understood. Recently, there has been increasing attention on the relationship between the immune system, gastrointestinal disorders and neurological issues in ASD, particularly in relation to the loss of specific species or a decrease in microbial diversity. It focuses on how gut microbiota dysbiosis can affect gut permeability, immune function and microbiota metabolites in ASD. However, a very complete study suggests that dysbiosis is a consequence of the disease and that it has practically no effect on autistic manifestations. This is a review of the relationship between the immune system, microbial diversity and the microbiome-gut-brain axis in the development of autistic symptoms severity and a proposal of a novel role of gut microbiome in ASD, where dysbiosis is a consequence of ASD-related behaviour and where dysbiosis in turn accentuates the autistic manifestations of the patients via the microbiome-gut-brain axis in a feedback circuit.

Synchrony 2022: Catalyzing Research and Treatments to Benefit Individuals with Neurodevelopmental Disorders including Autism Spectrum Disorders

A unique translational medicine conference for research into treatments that can benefit individuals with neurodevelopmental disorders (NDD), including autism spectrum disorder (ASD), has been developed and hosted by The BRAIN Foundation (Pleasanton, CA, USA) since 2019 [...]

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.

Mechanisms Underlying Circuit Dysfunction in Neurodevelopmental Disorders

Recent advances in genomics have revealed a wide spectrum of genetic variants associated with neurodevelopmental disorders at an unprecedented scale. An increasing number of studies have consistently identified mutations-both inherited and de novo-impacting the function of specific brain circuits. This suggests that, during brain development, alterations in distinct neural circuits, cell types, or broad regulatory pathways ultimately shaping synapses might be a dysfunctional process underlying these disorders. Here, we review findings from human studies and animal model research to provide a comprehensive description of synaptic and circuit mechanisms implicated in neurodevelopmental disorders. We discuss how specific synaptic connections might be commonly disrupted in different disorders and the alterations in cognition and behaviors emerging from imbalances in neuronal circuits. Moreover, we review new approaches that have been shown to restore or mitigate dysfunctional processes during specific critical windows of brain development. Considering the heterogeneity of neurodevelopmental disorders, we also highlight the recent progress in developing improved clinical biomarkers and strategies that will help to identify novel therapeutic compounds and opportunities for early intervention.

Autism Spectrum Disorder Initiation by Inflammation-Facilitated Neurotoxin Transport

Autism spectrum disorders have been linked to genetics, gut microbiota dysbiosis (gut dysbiosis), neurotoxin exposures, maternal allergies or autoimmune diseases. Two barriers to ingested neurotoxin transport into the central nervous system of a fetus or child are the gastrointestinal wall of the mother or child and the blood-brain barrier of the fetus or child. Inflammation from gut dysbiosis or inflammation from a disease or other agent can increase the gastrointestinal wall and the blood-brain barrier permeabilities to enable neurotoxins to reach the brain of a fetus or child. Postnatal gut dysbiosis is a particular inflammation risk for autism spectrum disorders caused by neurotoxin transport into a child's brain. An extensive gut dysbiosis or another source of inflammation such as a disease or other agent in combination with neurotoxins, including aluminum, mercury, lead, arsenic, cadmium, arsenic, organophosphates, and neurotoxic bacterial toxins and fungal toxins resulting from the gut dysbiosis, can elevate neurotoxin levels in a fetal or child brain to cause neurodevelopmental damage and initiate an autism spectrum disorder. The neurotoxins aluminum and mercury are especially synergistic in causing neurodevelopmental damage. There are three plausible causational pathways for autism spectrum disorders. They include inflammation and neurotoxin loading into the fetal brain during the prenatal neurodevelopment period, inflammation and neurotoxin loading into the brain during the postnatal neurodevelopment period or a two-stage loading of neurotoxins into the brain during both the prenatal and postnatal neurodevelopment periods.