Gastrointestinal symptoms in autism spectrum disorder: a meta-analysis

Prebiotic diet normalizes aberrant immune and behavioral phenotypes in a mouse model of autism spectrum disorder

Autism spectrum disorder (ASD) is a cluster of neurodevelopmental disorders characterized by deficits in communication and behavior. Increasing evidence suggests that the microbiota-gut-brain axis and the likely related immune imbalance may play a role in the development of this disorder. Gastrointestinal deficits and gut microbiota dysfunction have been linked to the development or severity of autistic behavior. Therefore, treatments that focus on specific diets may improve gastrointestinal function and aberrant behavior in individuals with ASD. In this study, we investigated whether a diet containing specific prebiotic fibers, namely, 3% galacto-oligosaccharide/fructo-oligosaccharide (GOS/FOS; 9:1), can mitigate the adverse effects of in utero exposure to valproic acid (VPA) in mice. Pregnant BALB/cByJ dams were injected with VPA (600 mg/kg, sc.) or phosphate-buffered saline (PBS) on gestational day 11 (G11). Male offspring were divided into four groups: (1) in utero PBS-exposed with a control diet, (2) in utero PBS-exposed with GOS/FOS diet, (3) in utero VPA-exposed with a control diet, and (4) in utero VPA-exposed with GOS/FOS diet. Dietary intervention started from birth and continued throughout the duration of the experiment. We showed that the prebiotic diet normalized VPA-induced alterations in male offspring, including restoration of key microbial taxa, intestinal permeability, peripheral immune homeostasis, reduction of neuroinflammation in the cerebellum, and impairments in social behavior and cognition in mice. Overall, our research provides valuable insights into the gut-brain axis involvement in ASD development. In addition, dietary interventions might correct the disbalance in gut microbiota and immune responses and, ultimately, might improve detrimental behavioral outcomes in ASD.

The metabolic role of vitamin D in children's neurodevelopment: a network study

Neurodevelopmental disorders are rapidly increasing in prevalence and have been linked to various environmental risk factors. Mounting evidence suggests a potential role of vitamin D in child neurodevelopment, though the causal mechanisms remain largely unknown. Here, we investigate how vitamin D deficiency affects children's communication development, particularly in relation to Autism Spectrum Disorder (ASD). We do so by developing an integrative network approach that combines metabolomic profiles, clinical traits, and neurodevelopmental data from a pediatric cohort. Our results show that low levels of vitamin D are associated with changes in the metabolic networks of tryptophan, linoleic, and fatty acid metabolism. These changes correlate with distinct ASD-related phenotypes, including delayed communication skills and respiratory dysfunctions. Additionally, our analysis suggests the kynurenine and serotonin sub-pathways may mediate the effect of vitamin D on early life communication development. Altogether, our findings provide metabolome-wide insights into the potential of vitamin D as a therapeutic option for ASD and other communication disorders.

Antibiotic use and risk of autism spectrum disorder and attention-deficit/hyperactivity disorder: a population-based cohort study

BACKGROUND

The gut microbiota is believed to influence neurodevelopment through the gut-brain axis, but prior studies have shown inconsistent results regarding early childhood antibiotic exposure and subsequent risk of autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD). The purpose of this study was to evaluate the hypothesis that exposure to antibacterial agents in the first 2 years of life increases the risk of ASD and/or ADHD.

METHODS

This was a retrospective cohort study using 2003-2019 data from the National Health Insurance Research Database in Taiwan. Livebirths born between 2004 and 2016 were identified and separated into singleton, full sibling, and exposure-discordant sibling pair cohorts. The exposure group included children who filled at least one prescription for antibacterial agents between 0 and 2 years old in outpatient settings. The outcome, ASD and/or ADHD, was defined by at least one inpatient or outpatient diagnosis. The maximum follow-up age was 15 years in this study. Potential neonatal, maternal and paternal confounders were adjusted for. Cox proportional hazards models were used to estimate the relative event risk.

RESULTS

The final sample contained 946,581 children in the singleton cohort, 1,142,693 children in the full sibling cohort, and 352,612 children in the exposure-discordant sibling pair cohort. Antibiotic exposure marginally increased the risk of ASD and/or ADHD in the singleton cohort (adjusted hazard ratio [aHR]: 1.06, 95% confidence interval [CI]: 1.04-1.07) and in the full sibling cohort (aHR: 1.03, 95% CI: 1.01-1.04). A slight decrease in the risk of ASD and/or ADHD was observed in the exposure-discordant sibling pair cohort (aHR: 0.92, 95% CI: 0.90-0.94).

CONCLUSIONS

The results suggest that early life antibiotic exposure has minimal impact on the risk of ASD and/or ADHD. Given that the estimated effects are marginal and close to null, concerns about ASD and/or ADHD risk increase should not postpone or deter timely and reasonable antibiotic use.

Associations between autistic and comorbid somatic problems of gastrointestinal disorders, food allergy, pain, and fatigue in adults

LAY ABSTRACT

What is already known about the topic?Autistic children frequently often have accompanying physical health problems. However, this has been much less studied in autistic men and women during adulthood.What does this article add?This is one of the first studies to investigate the associations between autistic and somatic problems in adults from the general population. Using a continuous measure of autistic symptom scores and a categorical definition of autism (referred to below as probable autism) which considered symptom severity, childhood age of onset, and functional impairment, we found that autistic problems and irritable bowel syndrome, food allergy, pain, and fatigue were associated in adults. Sex differences were present for pain and fatigue, for which the associations with autistic symptom scores were somewhat stronger in females than males. Regarding age differences, the associations with fatigue and having food allergy were more pronounced in younger adults. Conversely, older individuals had a higher risk of developing irritable bowel syndrome or experiencing pain if they met the criteria for probable autism.Implications for practice, research, or policyThere is a need for providing routine programs of screening, assessment, and treatment of autism-related somatic problems and developing evidence-based interventions for autistic individuals. These could be tailored to the needs of specific autistic populations. For example, autistic females could be given extra attention about the potential presence of pain and fatigue, younger adults about the potential presence of food allergy and fatigue, and older adults concerning the potential presence of irritable bowel syndrome and pain.

Autism gene variants disrupt enteric neuron migration and cause gastrointestinal dysmotility

The comorbidity of autism spectrum disorders and severe gastrointestinal symptoms is well-established, yet the molecular underpinnings remain unknown. The identification of high-confidence large-effect autism risk genes offers the opportunity to identify convergent, underlying biology by studying these genes in the context of the gastrointestinal system. Here we show that the expression of these genes is enriched in human prenatal gut neurons as well as their migratory progenitors, suggesting that the development and/or function of these neurons may be disrupted by autism-associated pathogenic variants, leading to gastrointestinal dysfunction. Here we document the prevalence of gastrointestinal issues in patients with large-effect variants in sixteen of these genes, highlighting dysmotility, consistent with potential enteric neuron dysfunction. Using the high-throughput diploid frog Xenopus tropicalis , we individually target five of these genes ( SYNGAP1, CHD8, SCN2A, CHD2 , and DYRK1A ) and observe disrupted enteric neuronal progenitor migration for each. More extensive analysis of DYRK1A reveals that perturbation causes gut dysmotility in vivo , which can be ameliorated by treatment with a selective serotonin reuptake inhibitor (escitalopram) or a serotonin receptor 6 agonist, identified by in vivo drug screening. This work suggests that atypical development of enteric neurons contributes to the gastrointestinal distress commonly seen in individuals with autism and that increasing serotonin signaling may be a productive therapeutic avenue.

The regulation of enteric neuron connectivity by semaphorin 5A is affected by the autism-associated S956G missense mutation

The neural network of the enteric nervous system (ENS) underlies gastrointestinal functions. However, the molecular mechanisms involved in enteric neuronal connectivity are poorly characterized. Here, we studied the role of semaphorin 5A (Sema5A), previously characterized in the central nervous system, on ENS neuronal connectivity. Sema5A is linked to autism spectrum disorder (ASD), a neurodevelopmental disorder frequently associated with gastrointestinal comorbidities, and potentially associated with ENS impairments. This study investigated in rat enteric neuron cultures and gut explants the role of Sema5A on enteric neuron connectivity and the impact of ASD-associated mutations on Sema5A activity. Our findings demonstrated that Sema5A promoted axonal complexity and reduced functional connectivity in enteric neurons. Strikingly, the ASD-associated mutation S956G in Sema5A strongly affected these activities. This study identifies a critical role of Sema5A in the ENS as a regulator of neuronal connectivity that might be compromised in ASD.

Prevalence and determinants of constipation in children in Asia: a systematic review and meta-analysis

Background

Constipation is prevalent worldwide, significantly increasing healthcare costs and diminishing the quality of life in children affected. Current studies have yielded mixed results regarding the factors associated with constipation, and mainly focusing on patients outside of Asia. Moreover, most of these studies lack focus on the paediatric population. This study aimed to identify the prevalence and associated factors of constipation among children in Asia.

Methods

In this systematic review and meta-analysis, we systematically searched PubMed, Scopus, and Cochrane for cohort and cross-sectional studies published from database inception up to October 12, 2022, and continued with manual searching until September 2, 2023. Eligible studies were those that included children in Asia aged 0-18 years old suffering from idiopathic constipation, with prevalence value provided in the English abstract. The analysis included clinical and general population. Children with organic constipation, who had undergone gastrointestinal surgery, or with congenital defects were excluded, as these factors affect the incidence of constipation. Data included in the analysis were extracted from published reports only. The extracted data were pooled using random-effects model to analyse the prevalence of constipation in children in Asia. This study is registered with PROSPERO, CRD42022367122.

Findings

Out of 4410 systematically searched studies and 36 manually searched ones, a total of 50 studies were included in the final analysis, encompassing data from 311,660 children residing in Asia. The pooled prevalence of constipation was 12.0% (95% CI 9.3-14.6%, I2 = 99.8%). There was no significant difference in constipation prevalence observed by sex and geographical location. Nonetheless, adolescents and children aged 1-9 years exhibited a significantly higher prevalence constipation compared to infants (p < 0.0001) Additionally, significant differences in constipation rates were observed across various diagnostic methods, population sources, and mental health conditions.

Interpretation

Despite the high heterogeneity resulting from varying diagnostic tools or definitions used among studies, our review adds to the literature on constipation among children in Asia. It reveals a notably high prevalence of constipation in this demographic. Diagnostic methods, age, and compromised mental health emerged as significant influencers of constipation among children in Asia, highlighting potential strategies to mitigate constipation prevalence in children in Asia.

Funding

The National Science and Technology Council, Taiwan.

Characterization of Initial Gastrointestinal Evaluation of Children with Autism Spectrum Disorder: A Descriptive Study

Autism spectrum disorder (ASD) is a multifactorial, pervasive neurodevelopmental disorder affecting 1 in 36 children in the United States. Given the rising prevalence and significant economic and social costs associated with ASD, it is critical that continued efforts be made towards better understanding the underlying etiology as well as management of the condition and its commonly associated comorbidities. It has been estimated that upwards of 70% of children with ASD have a positive history of gastrointestinal (GI) symptoms. In this retrospective, descriptive study, we identified 131 patients with diagnosis of autism spectrum disorder who presented for initial evaluation by pediatric gastroenterology at the Baystate Children's Specialty Center. We collected data from chart review of these patients with a particular focus on reason for referral, components of evaluation as well as results of said evaluation. Of the 131 patients, the most frequent reason for referral included constipation (42.7%), abdominal pain (27.5%), and feeding difficulties (26.7%). After completion of the evaluation, 60.3% of patients were ultimately diagnosed with a functional gastrointestinal condition. Of patients who completed endoscopic evaluation, 40% of patients were found to have grossly abnormal and 40% were found to have pathologically abnormal EGD. The majority of patients were recommended to have diagnostic evaluation; however, a large proportion of them were unable to complete said evaluation. The majority of patients were found to have abnormal testing; however, the majority of patients were additionally diagnosed with a functional gastrointestinal condition.

Infant microbes and metabolites point to childhood neurodevelopmental disorders

This study has followed a birth cohort for over 20 years to find factors associated with neurodevelopmental disorder (ND) diagnosis. Detailed, early-life longitudinal questionnaires captured infection and antibiotic events, stress, prenatal factors, family history, and more. Biomarkers including cord serum metabolome and lipidome, human leukocyte antigen (HLA) genotype, infant microbiota, and stool metabolome were assessed. Among the 16,440 Swedish children followed across time, 1,197 developed an ND. Significant associations emerged for future ND diagnosis in general and for specific ND subtypes, spanning intellectual disability, speech disorder, attention-deficit/hyperactivity disorder, and autism. This investigation revealed microbiome connections to future diagnosis as well as early emerging mood and gastrointestinal problems. The findings suggest links to immunodysregulation and metabolism, compounded by stress, early-life infection, and antibiotics. The convergence of infant biomarkers and risk factors in this prospective, longitudinal study on a large-scale population establishes a foundation for early-life prediction and intervention in neurodevelopment.

Prenatal and postnatal neuroimmune interactions in neurodevelopmental disorders

The intricate relationship between immune dysregulation and neurodevelopmental disorders (NDDs) has been observed across the stages of both prenatal and postnatal development. In this Review, we provide a comprehensive overview of various maternal immune conditions, ranging from infections to chronic inflammatory conditions, that impact the neurodevelopment of the fetus during pregnancy. Furthermore, we examine the presence of immunological phenotypes, such as immune-related markers and coexisting immunological disorders, in individuals with NDDs. By delving into these findings, we shed light on the potential underlying mechanisms responsible for the high occurrence of immune dysregulation alongside NDDs. We also discuss current mouse models of NDDs and their contributions to our understanding of the immune mechanisms underlying these diseases. Additionally, we discuss how neuroimmune interactions contribute to shaping the manifestation of neurological phenotypes in individuals with NDDs while also exploring potential avenues for mitigating these effects.

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.

Outcomes of children with constipation and autism spectrum disorder treated with antegrade continence enemas

BACKGROUND

Treatment of functional constipation (FC) in children with autism spectrum disorder (ASD) is challenging due to sensory and behavioral issues. We aimed to understand whether antegrade continence enemas (ACEs) are successful in the treatment of FC in children with ASD.

METHODS

A single-institution retrospective review was performed in children diagnosed with ASD and FC who underwent appendicostomy or cecostomy placement from 2007 to 2019. Descriptive statistics regarding soiling and complications were calculated.

RESULTS

There were 33 patients included, with a median age of 9.7 years at the time of ACE initiation. The average intelligence quotient was 63.6 (SD = 18.0, n = 12), the average behavioral adaptive score was 59.9 (SD = 11.1, n = 13), and the average total Child Behavioral Checklist score was 72.5 (SD = 7.1, n = 10). Soiling rates were significantly lower following ACE initiation (42.3% vs. 14.8%, p = 0.04). Behavioral issues only prevented 1 patient (3.0%) from proper ACE use. Eleven patients (36.6%) were able to transition to laxatives. There were significant improvements in patient-reported outcomes measures and quality of life.

CONCLUSION

Placement of an appendicostomy or cecostomy for management of FC in children with severe ASD was successful in treating constipation and improving quality of life.

High-fat diet-induced obesity causes intestinal Th17/Treg imbalance that impairs the intestinal barrier and aggravates anxiety-like behavior in mice

The prevalence of autism spectrum disorders (ASD) has been steadily increasing, and growing evidence suggests a link between high-fat diet (HFD), obesity, and ASD; however, the mechanism underlying this association remains elusive. Herein, BTBR T + tf/J (BTBR) inbred mice (a mouse ASD model) and C57Bl/6J (C57) mice were fed an HFD and normal diet (ND) for 8 weeks (groups: C57 + ND, C57 + HFD, BTBR + ND, and BTBR + HFD). Subsequently, mice underwent behavioral assessments, followed by intestinal tissues harvesting to detect expression of intestinal barrier proteins and inflammatory factors and immune cell numbers, and a correlation analysis. HFD-fed BTBR mice developed obesity, elevated blood sugar, significantly aggravated anxiety-like behaviors, impaired intestinal barrier function, intestinal inflammation with elevated CD4+IL17+ T (Th17) cells and reduced CD4+Foxp3+ T (Treg) cells, exhibiting reduced expression of proteins related to AMPK regulatory pathway (AMPK, p-AMPK, SIRT1). Correlation analysis revealed that the degree of behavioral anxiety, the degree of intestinal barrier damage, the severity of intestinal inflammation, and the degree of immune cell imbalance positively correlated with each other. Accordingly, HFD-induced obesity may cause intestinal Th17/Treg imbalance via the AMPK-SIRT1 pathway, leading to an inflammatory environment in the intestine, impairing intestinal barrier function, and ultimately aggravating anxiety-like behaviors in mice.

Colitis reduces active social engagement in mice and is ameliorated by supplementation with human microbiota members

Multiple neurological disorders are associated with gastrointestinal (GI) symptoms, including autism spectrum disorder (ASD). However, it is unclear whether GI distress itself can modify aspects of behavior. Here, we show that mice that experience repeated colitis have impaired active social engagement, as measured by interactions with a foreign mouse, even though signs of colitis were no longer present. We then tested the hypothesis that individuals with ASD harbor a microbiota that might differentially influence GI health by performing microbiota transplantation studies into male germfree animals, followed by induction of colitis. Animals that harbor a microbiota from ASD individuals have worsened gut phenotypes when compared to animals colonized with microbiotas from familial neurotypical (NT) controls. We identify the enrichment of Blautia species in all familial NT controls and observe an association between elevated abundance of Bacteroides uniformis and reductions in intestinal injury. Oral treatment with either of these microbes reduces colon injury in mice. Finally, provision of a Blautia isolate from a NT control ameliorates gut injury-associated active social engagement in mice. Collectively, our data demonstrate that past intestinal distress is associated with changes in active social behavior in mice that can be ameliorated by supplementation of members of the human microbiota.

Probiotics in autism spectrum disorders: a systematic review of clinical studies and future directions

CONTEXT

It is hypothesized that gut dysbiosis, a typical feature of patients with autism spectrum disorder (ASD), could be involved in the origin of this neurodevelopmental disorder. Therefore, the use of probiotics to restore gastrointestinal (GI) equilibrium might be a promising therapeutic strategy due to its capacity to balance the gut-brain axis and behavioral responses.

OBJECTIVE

To summarize current knowledge on the use of probiotics to treat core clinical ASD symptoms and concomitant GI signs, compare the design of published studies with those of ongoing trials, assess the near future of this field, and provide recommendations for improving novel studies.

DATA SOURCES

The literature search was conducted in February 2020 and updated in March 2021, using a broad range of bibliographic and clinical trial-specific databases.

DATA EXTRACTION

Data were extracted using a standardized form, and articles reporting on 28 clinical studies (already published or still ongoing) were included. The risk of bias in clinical studies was evaluated using the Cochrane Collaboration Risk of Bias Assessment tool for randomized trials and the Risk of Bias in Nonrandomized Studies-Interventions tool for nonrandomized trials.

RESULTS

The results suggest that probiotics improve ASD-like social deficits, GI symptoms, and gut microbiota profile. However, inconsistencies among studies and their methodological limitations make it difficult to draw any conclusions regarding the efficacy of probiotics in ASD. This review provides specific suggestions for future research to improve the quality of the studies.

CONCLUSIONS

Although ongoing studies have improved designs, the available knowledge does not permit solid conclusions to be made regarding the efficacy of probiotics in ameliorating the symptoms (psychiatric and/or GI) associated with ASD. Thus, more high-quality research and new approaches are needed to design effective probiotic strategies for ASD.

Effect of Osteopathic Manipulation in an Autism Spectrum Child With Speech Impairment and Attention Deficit: A Case Report

Autism spectrum disorder (ASD) is a complex neurodevelopmental condition characterized by challenges in communication, social interaction, and repetitive behaviors. Children with ASD often experience comorbidities such as speech impairment and attention deficit, which can significantly impact their quality of life and ability to engage in daily activities. This case report aims to investigate the potential benefits of osteopathic manipulation in addressing speech impairment and attention deficit in a child diagnosed with ASD. A four-year-old male child diagnosed with ASD, presenting with speech impairment and attention deficit, received a series of osteopathic manipulation sessions over a period of 12 weeks. The treatment protocol was tailored to address musculoskeletal dysfunctions, cranial restrictions, somatic dysfunctions, and digestive system dysfunctions identified through osteopathic assessment. Following the osteopathic manipulation sessions, improvements were observed in the child's speech fluency and attention span. The child demonstrated increased engagement in communication activities and showed enhanced focus during therapy sessions. Additionally, improvements were noted in the child's overall behavior and social interaction skills. This case report suggests that osteopathic manipulation may be a beneficial adjunctive therapy for children with ASD experiencing speech impairment and attention deficit. Further research with larger sample sizes and controlled study designs is warranted to validate these findings and elucidate the mechanisms underlying the observed improvements. Osteopathic manipulation holds promise as a non-invasive, holistic approach to addressing various aspects of ASD, contributing to the multidisciplinary management of this complex condition.

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.

Dietary intake and gastrointestinal symptoms are altered in children with Autism Spectrum Disorder: the relative contribution of autism-linked traits

BACKGROUND

Dietary and gastrointestinal (GI) problems have been frequently reported in autism spectrum disorder (ASD). However, the relative contributions of autism-linked traits to dietary and GI problems in children with ASD are poorly understood. This study firstly compared the dietary intake and GI symptoms between children with ASD and typically developing children (TDC), and then quantified the relative contributions of autism-linked traits to dietary intake, and relative contributions of autism-linked traits and dietary intake to GI symptoms within the ASD group.

METHODS

A sample of 121 children with ASD and 121 age-matched TDC were eligible for this study. The dietary intake indicators included food groups intakes, food variety, and diet quality. The autism-linked traits included ASD symptom severity, restricted repetitive behaviors (RRBs), sensory profiles, mealtime behaviors, and their subtypes. Linear mixed-effects models and mixed-effects logistic regression models were used to estimate the relative contributions.

RESULTS

Children with ASD had poorer diets with fewer vegetables/fruits, less variety of food, a higher degree of inadequate/unbalanced dietary intake, and more severe constipation/total GI symptoms than age-matched TDC. Within the ASD group, compulsive behavior (a subtype of RRBs) and taste/smell sensitivity were the only traits associated with lower vegetables and fruit consumption, respectively. Self-injurious behavior (a subtype of RRBs) was the only contributing trait to less variety of food. Limited variety (a subtype of mealtime behavior problems) and ASD symptom severity were the primary and secondary contributors to inadequate dietary intake, respectively. ASD symptom severity and limited variety were the primary and secondary contributors to unbalanced dietary intake, respectively. Notably, unbalanced dietary intake was a significant independent factor associated with constipation/total GI symptoms, and autism-linked traits manifested no contributions.

CONCLUSIONS

ASD symptom severity and unbalanced diets were the most important contributors to unbalanced dietary intake and GI symptoms, respectively. Our findings highlight that ASD symptom severity and unbalanced diets could provide the largest benefits for the dietary and GI problems of ASD if they were targeted for early detection and optimal treatment.

Between Dysbiosis, Maternal Immune Activation and Autism: Is There a Common Pathway?

Autism spectrum disorder (ASD) is a neuropsychiatric condition characterized by impaired social interactions and repetitive stereotyped behaviors. Growing evidence highlights an important role of the gut-brain-microbiome axis in the pathogenesis of ASD. Research indicates an abnormal composition of the gut microbiome and the potential involvement of bacterial molecules in neuroinflammation and brain development disruptions. Concurrently, attention is directed towards the role of short-chain fatty acids (SCFAs) and impaired intestinal tightness. This comprehensive review emphasizes the potential impact of maternal gut microbiota changes on the development of autism in children, especially considering maternal immune activation (MIA). The following paper evaluates the impact of the birth route on the colonization of the child with bacteria in the first weeks of life. Furthermore, it explores the role of pro-inflammatory cytokines, such as IL-6 and IL-17a and mother's obesity as potentially environmental factors of ASD. The purpose of this review is to advance our understanding of ASD pathogenesis, while also searching for the positive implications of the latest therapies, such as probiotics, prebiotics or fecal microbiota transplantation, targeting the gut microbiota and reducing inflammation. This review aims to provide valuable insights that could instruct future studies and treatments for individuals affected by ASD.

Pathogenic/likely pathogenic mutations identified in Vietnamese children diagnosed with autism spectrum disorder using high-resolution SNP genotyping platform

Among the most prevalent neurodevelopmental disorders, Autism Spectrum Disorder (ASD) is highly diverse showing a broad phenotypic spectrum. ASD also couples with a broad range of mutations, both de novo and inherited. In this study, we used a proprietary SNP genotyping chip to analyze the genomic DNA of 250 Vietnamese children diagnosed with ASD. Our Single Nucleotide Polymorphism (SNP) genotyping chip directly targets more than 800 thousand SNPs in the genome. Our primary focus was to identify pathogenic/likely pathogenic mutations that are potentially linked to more severe symptoms of autism. We identified and validated 23 pathogenic/likely pathogenic mutations in this initial study. The data shows that these mutations were detected in several cases spanning multiple biological pathways. Among the confirmed SNPs, mutations were identified in genes previously known to be strongly associated with ASD such as SLCO1B1, ACADSB, TCF4, HCP5, MOCOS, SRD5A2, MCCC2, DCC, and PRKN while several other mutations are known to associate with autistic traits or other neurodevelopmental disorders. Some mutations were found in multiple patients and some patients carried multiple pathogenic/likely pathogenic mutations. These findings contribute to the identification of potential targets for therapeutic solutions in what is considered a genetically heterogeneous neurodevelopmental disorder.

Psychiatric Features of Children with Chronic Functional Constipation: Focusing on Individuals with Autism Spectrum Disorder

PURPOSE

The present study aimed to assess the psychiatric characteristics of children with chronic functional constipation using the Aberrant Behavior Checklist-Japanese version and the Pervasive Developmental Disorders/Autism Society Japan Rating Scale, and to examine the frequency of autism spectrum disorder in children with chronic functional constipation. We also investigated differences in treatment duration between children with and without autism spectrum disorder.

METHODS

Treatment outcomes were examined retrospectively for 55 participants (chronic functional constipation group: n = 30, mean age 3.4 years; control group: n = 25, mean age, 4.5 years). The association between chronic functional constipation and autism spectrum disorder was evaluated using multivariable logistic regression analysis.

RESULTS

The mean Aberrant Behavior Checklist score and frequency of individuals with autism spectrum disorder were significantly higher in the chronic functional constipation group. After adjusting for age and sex, chronic functional constipation was significantly associated with autism spectrum disorder. In the chronic functional constipation group, the frequency of onset was significantly higher in children with autism spectrum disorder under 1 year of age. When treated, the mean duration of constipation was significantly longer in children with autism spectrum disorder.

CONCLUSION

Pediatricians, pediatric surgeons, and child psychiatrists should work closely to ensure appropriate treatment of chronic functional constipation in children with autism spectrum disorder.

The search for gastrointestinal inflammation in autism: a systematic review and meta-analysis of non-invasive gastrointestinal markers

BACKGROUND

Gastrointestinal symptoms and inflammatory gastrointestinal diseases exist at higher rates in the autistic population. It is not clear however whether autism is associated with elevated gastrointestinal inflammation as studies examining non-invasive faecal biomarkers report conflicting findings. To understand the research landscape and identify gaps, we performed a systematic review and meta-analysis of studies measuring non-invasive markers of gastrointestinal inflammation in autistic and non-autistic samples. Our examination focused on faecal biomarkers as sampling is non-invasive and these markers are a direct reflection of inflammatory processes in the gastrointestinal tract.

METHODS

We extracted data from case-control studies examining faecal markers of gastrointestinal inflammation. We searched PubMed, Embase, Cochrane CENTRAL, CINAHL, PsycINFO, Web of Science Core Collection and Epistemonikos and forward and backwards citations of included studies published up to April 14, 2023 (PROSPERO CRD42022369279).

RESULTS

There were few studies examining faecal markers of gastrointestinal inflammation in the autistic population, and many established markers have not been studied. Meta-analyses of studies examining calprotectin (n = 9) and lactoferrin (n = 3) were carried out. A total of 508 autistic children and adolescents and 397 non-autistic children and adolescents were included in the meta-analysis of calprotectin studies which found no significant group differences (ROM: 1.30 [0.91, 1.86]). Estimated differences in calprotectin were lower in studies with siblings and studies which did not exclude non-autistic controls with gastrointestinal symptoms. A total of 139 autistic participants and 75 non-autistic controls were included in the meta-analysis of lactoferrin studies which found no significant group differences (ROM: 1.27 [0.79, 2.04]).

LIMITATIONS

All studies included in this systematic review and meta-analysis examined children and adolescents. Many studies included non-autistic controls with gastrointestinal symptoms which limit the validity of their findings. The majority of studies of gastrointestinal inflammation focused on children under 12 with few studies including adolescent participants. Most studies that included participants aged four or under did not account for the impact of age on calprotectin levels. Future studies should screen for relevant confounders, include larger samples and explore gastrointestinal inflammation in autistic adolescents and adults.

CONCLUSIONS

There is no evidence to suggest higher levels of gastrointestinal inflammation as measured by calprotectin and lactoferrin are present in autistic children and adolescents at the population level. Preliminary evidence suggests however that higher calprotectin levels may be present in a subset of autistic participants, who may be clinically characterised by more severe gastrointestinal symptoms and higher levels of autistic traits.

The many faces of microbiota-gut-brain axis in autism spectrum disorder

The gut-brain axis is gaining more attention in neurodevelopmental disorders, especially autism spectrum disorder (ASD). Many factors can influence microbiota in early life, including host genetics and perinatal events (infections, mode of birth/delivery, medications, nutritional supply, and environmental stressors). The gut microbiome can influence blood-brain barrier (BBB) permeability, drug bioavailability, and social behaviors. Developing microbiota-based interventions such as probiotics, gastrointestinal (GI) microbiota transplantation, or metabolite supplementation may offer an exciting approach to treating ASD. This review highlights that RNA sequencing, metabolomics, and transcriptomics data are needed to understand how microbial modulators can influence ASD pathophysiology. Due to the substantial clinical heterogeneity of ASD, medical caretakers may be unlikely to develop a broad and effective general gut microbiota modulator. However, dietary modulation followed by administration of microbiota modulators is a promising option for treating ASD-related behavioral and gastrointestinal symptoms. Future work should focus on the accuracy of biomarker tests and developing specific psychobiotic agents tailored towards the gut microbiota seen in ASD patients, which may include developing individualized treatment options.

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 synbiotic formulation of Lactobacillus reuteri and inulin alleviates ASD-like behaviors in a mouse model: the mediating role of the gut-brain axis

Autism Spectrum Disorder (ASD), a complex neurodevelopmental disorder marked by social communication deficits and repetitive behaviors, may see symptom amelioration through gut microbiota modulation. This study investigates the effects of a synbiotic - specifically a probiotic amplified by prebiotic supplementation - on ASD-like mouse model's social deficiencies. This model was established via valproic acid injection into pregnant females. Post-weaning, male progeny received daily synbiotic treatment, a combination of Lactobacillus reuteri (L. reuteri) and inulin, for four weeks. Results indicated that the synbiotic rectified social impairments and attenuated inflammatory cytokine expressions in the brain. Moreover, synbiotic intervention protected gut barrier integrity and altered the gut microbiota composition, enhancing the butyrate-producing Bifidobacterium abundance. The synbiotic elevated metabolites such as butyrate and 3-hydroxybutyric acid (3-HB), alongside upregulated genes associated with 3-HB synthesis in the colon and liver, and brain receptors. Conclusively, the synbiotic combination of L. reuteri and inulin mitigated ASD-related social impairments, partially via their regulatory effect on the gut-brain axis.

Genetic liability for gastrointestinal inflammation disorders and association with gastrointestinal symptoms in children with and without autism

Children with autism spectrum disorder (ASD) have a greater prevalence of gastrointestinal (GI) symptoms than children without ASD. We tested whether polygenic scores for each of three GI disorders (ulcerative colitis, inflammatory bowel disease, and Crohn's disease) were related to GI symptoms in children with and without ASD. Using genotyping data (564 ASD cases and 715 controls) and external genome-wide association study summary statistics, we computed GI polygenic scores for ulcerative colitis (UC-PGS), inflammatory bowel disease (IDB-PGS), and Crohn's disease (CD-PGS). Multivariable logistic regression models, adjusted for genetic ancestry, were used to estimate associations between each GI-PGS and (1) ASD case-control status, and (2) specific GI symptoms in neurotypical children and separately in ASD children. In children without ASD, polygenic scores for ulcerative colitis were significantly associated with experiencing any GI symptom (adjusted odds ratio (aOR) = 1.36, 95% confidence interval (CI) = 1.03-1.81, p = 0.03) and diarrhea specifically (aOR = 5.35, 95% CI = 1.77-26.20, p = 0.01). Among children without ASD, IBD-PGS, and Crohn's PGS were significantly associated with diarrhea (aOR = 3.55, 95% CI = 1.25-12.34, p = 0.02) and loose stools alternating with constipation (aOR = 2.57, 95% CI = 1.13-6.55, p = 0.03), respectively. However, the three PGS were not associated with GI symptoms in the ASD case group. Furthermore, polygenic scores for ulcerative colitis significantly interacted with ASD status on presentation of any GI symptom within a European ancestry subset (aOR = 0.42, 95% CI = 0.19-0.88, p = 0.02). Genetic risk factors for some GI symptoms differ between children with and without ASD. Furthermore, our finding that increased genetic risks for GI inflammatory disorders are associated with GI symptoms in children without ASD informs future work on the early detection of GI disorders.

Advances in the Treatment of Autism Spectrum Disorder: Current and Promising Strategies

Autism spectrum disorder (ASD) is an umbrella term for developmental disorders characterized by social and communication impairments, language difficulties, restricted interests, and repetitive behaviors. Current management approaches for ASD aim to resolve its clinical manifestations based on the type and severity of the disability. Although some medications like risperidone show potential in regulating ASD-associated symptoms, a comprehensive treatment strategy for ASD is yet to be discovered. To date, identifying appropriate therapeutic targets and treatment strategies remains challenging due to the complex pathogenesis associated with ASD. Therefore, a comprehensive approach must be tailored to target the numerous pathogenetic pathways of ASD. From currently viable and basic treatment strategies, this review explores the entire field of advancements in ASD management up to cutting-edge modern scientific research. A novel systematic and personalized treatment approach is suggested, combining the available medications and targeting each symptom accordingly. Herein, summarize and categorize the most appropriate ways of modern ASD management into three distinct categories: current, promising, and prospective strategies.

Comparing Gastrointestinal Endoscopy Findings in Children with Autism, Developmental Delay, or Typical Development

OBJECTIVE

To compare endoscopic and histologic upper endoscopy (esophagogastroduodenoscopy [EGD]) findings in children with autism spectrum disorders (ASD) to age- and gender-matched controls with developmental delay (DD) or with typical development (TD).

METHODS

Retrospective, cross-sectional study of children undergoing EGD, identifying those diagnosed with ASD, and matching on age and gender to children with DD or TD in ratio of 1:1:2. Rates of EGD findings were compared between the 3 groups using χ² or Fisher exact test. Multivariable linear regression was performed to identify predictors of abnormal histology.

RESULTS

A total of 2104 patients were included (526 ASD; 526 DD; 1052 TD). Children with ASD had higher rates of abnormal esophageal histology (ASD 38.4%; DD 33.4%; TD 30.4%, P = .008), particularly esophagitis. In multivariable modeling, ASD diagnosis was an independent predictor of abnormal esophageal histology (OR [95% CI] 1.38 [1.09, 1.76]) compared with TD. Stomach findings did not differ among the groups. In the duodenum, histologic abnormalities were observed with lower frequency in ASD (ASD 17.0%; DD 20.1%; TD 24.2%, P = .005). In multivariable analysis, ASD diagnosis was not a significant predictor (OR 0.78 [0.56, 1.09]) of abnormal duodenal histology.

CONCLUSIONS

Children with ASD have higher rates of histologic esophagitis compared with age- and gender-matched DD and TD controls. ASD was a significant independent predictor of abnormal esophageal, but not, duodenal, histology. These results underscore the importance of EGD in children with ASD.

[Gut Microbiota and Autism Spectrum Disorders: An Overview of Correlations and Potential Implications for Therapeutic Interventions]

Gut Microbiota and Autism Spectrum Disorders: An Overview of Correlations and Potential Implications for Therapeutic Interventions Abstract: At the beginning of research on microbiota, researchers focused mainly on the role of microbiota dysbiosis in the development of gastrointestinal diseases. However, over the last years, researchers have also identified correlations with other physical processes and neuropsychiatric diseases such as autism spectrum disorder. These correlations are believed to be at least partly mediated through the brain-gut-microbiome axis. An altered composition of microbiota in patients with autism spectrum disorder was detected compared to healthy controls. Today, the discussion centers around a possible systemic impact of the metabolites of some microbiota or microbiota-induced chronic inflammatory processes on the brain (mediated through the brain-gut-microbiome axis) as an underlying mechanism. Still, the specific underlying mechanisms remain largely unknown, so conclusions on therapeutic implications are difficult to determine. Here, we describe some promising approaches to improving autistic behavior through dietary changes, the use of prebiotics and probiotics, stool transplantation from healthy controls, and restricted absorbance of certain metabolites. We need further clinical studies of high quality to fully understand the pathophysiology of autism spectrum disorder and to improve diagnostic and therapeutic strategies.

Intestinal Symptoms Among Children aged 2-7 Years with Autism Spectrum Disorder in 13 Cities of China

BACKGROUND

Autism spectrum disorder (ASD) is a multifactorial, pervasive, neurodevelopmental disorder, of which intestinal symptoms collectively represent one of the most common comorbidities.

METHODS

In this study, 1,222 children with ASD and 1,206 typically developing (TD) children aged 2-7 years were enrolled from 13 cities in China. Physical measurement and basic information questionnaires were conducted in ASD and TD children. The Childhood Autism Rating Scale (CARS), Social Responsiveness Scale (SRS), and Autism Behavior Checklist (ABC) were used to evaluate the clinical symptoms of children with ASD. The six-item Gastrointestinal Severity Index (6-GSI) was used to evaluate the prevalence of intestinal symptoms in two groups.

RESULTS

The detection rates of constipation, stool odor, and total intestinal symptoms in ASD children were significantly higher than those in TD children (40.098% vs. 25.622%, 17.021% vs. 9.287%, and 53.601% vs. 41.294%, respectively). Autistic children presenting with intestinal comorbidity had significantly higher scores on the ABC, SRS, CARS, and multiple subscales than autistic children without intestinal symptoms, suggesting that intestinal comorbidity may exacerbates the core symptoms of ASD children.

CONCLUSION

Intestinal dysfunction was significantly more common in autistic than in TD children. This dysfunction may aggravate the core symptoms of children with ASD.

Altered Gut Microbiota and Short-chain Fatty Acids in Chinese Children with Constipated Autism Spectrum Disorder

Gastrointestinal symptoms are more prevalent in children with autism spectrum disorder (ASD) than in typically developing (TD) children. Constipation is a significant gastrointestinal comorbidity of ASD, but the associations among constipated autism spectrum disorder (C-ASD), microbiota and short-chain fatty acids (SCFAs) are still debated. We enrolled 80 children, divided into the C-ASD group (n = 40) and the TD group (n = 40). In this study, an integrated 16S rRNA gene sequencing and gas chromatography-mass spectrometry-based metabolomics approach was applied to explore the association of the gut microbiota and SCFAs in C-ASD children in China. The community diversity estimated by the Observe, Chao1, and ACE indices was significantly lower in the C-ASD group than in the TD group. We observed that Ruminococcaceae_UCG_002, Erysipelotrichaceae_UCG_003, Phascolarctobacterium, Megamonas, Ruminiclostridium_5, Parabacteroides, Prevotella_2, Fusobacterium, and Prevotella_9 were enriched in the C-ASD group, and Anaerostipes, Lactobacillus, Ruminococcus_gnavus_group, Lachnospiraceae_NK4A136_group, Ralstonia, Eubacterium_eligens_group, and Ruminococcus_1 were enriched in the TD group. The propionate levels, which were higher in the C-ASD group, were negatively correlated with the abundance of Lactobacillus taxa, but were positively correlated with the severity of ASD symptoms. The random forest model, based on the 16 representative discriminant genera, achieved a high accuracy (AUC = 0.924). In conclusion, we found that C-ASD is related to altered gut microbiota and SCFAs, especially decreased abundance of Lactobacillus and excessive propionate in faeces, which provide new clues to understand C-ASD and biomarkers for the diagnosis and potential strategies for treatment of the disorder. This study was registered in the Chinese Clinical Trial Registry ( www.chictr.org.cn ; trial registration number ChiCTR2100052106; date of registration: October 17, 2021).

Quasi-experimental Controlled Study on the Effect of Autism Resource Clinic Guardian Attendance at a Military Treatment Facility

INTRODUCTION

Autism spectrum disorder (ASD) is a complex neurodevelopmental condition that requires multidisciplinary care. Evidence-based practice indicates that early intervention may improve long-term ASD outcomes. The Autism Resource Clinic (ARC) provides an educational session for guardians empowering them to build a personalized ASD team for their child. We examined the impact of guardian attendance of an ARC at a Military Treatment Facility on time to initiation of patient services and guardian stress level.

MATERIALS AND METHODS

A quasi-experimental controlled study was conducted comparing a group of guardians attending the ARC with a group of guardians not attending the ARC following a child's initial ASD diagnosis. ARC speakers included medical, county/state, community/military, and advocacy experts. Surveys were completed at diagnosis, 1, 2, and 3 mo postdiagnosis. Initiation of patient services and Parental Stress Scale scores were compared between groups using independent samples t-test, chi-square tests, or nonparametric tests, as appropriate.

RESULTS

Use of Applied Behavioral Analysis was significantly higher among ARC attendees vs. nonattendees (73.3% vs. 33.3%, P = 0.028). County early intervention was more frequent among ARC attendees versus nonattendees (40% vs. 13.3%, P = 0.09). Of borderline significance, median time to initiation of genetics services was greater in ARC attendees vs. nonattendees (106 vs. 65.5, P = 0.10). The two groups did not differ on changes in Parental Stress Scale score from baseline to follow-up months 1, 2, or 3.

CONCLUSIONS

Although ARC did not influence time to initiation of patient services or guardian stress level, attendance of ARC was associated with more frequent use of Applied Behavioral Analysis services and county early intervention services. This pilot study is unique as it targets guardians of ASD patients within military treatment facilities. Study limitations include data collection during the coronavirus disease 2019 pandemic, sequential evaluation of experimental and control groups, sample size and generalizability. A large, multicenter, randomized controlled trial is required to better assess the impact of this educational opportunity among military populations.

Gastrointestinal and Sleep Issues in Toddlers With Autism Versus Other Neurodevelopmental Disorders

Neurodevelopmental disorders (NDDs) are frequently associated with gastrointestinal symptoms (GIS) and sleep issues, but there are insufficient data on the occurrence of these symptoms in young children with autism spectrum disorder (ASD) compared with other NDDs. We abstracted data on 500 children aged 18 to 36 months with ASD and 146 children aged 18 to 47 months with non-ASD NDDs to compare the frequency of these symptoms. In the overall sample, there was a high rate of GIS (46.0%) and sleep difficulties (22.6%). In age-adjusted analyses, children with non-ASD NDDs were more likely to have GIS (61.0% vs 41.6%; adjusted odds ratio [OR] = 2.35; 95% confidence interval = 1.56-3.56) and sleep difficulties (34.9% vs 19.0%; adjusted OR = 2.08; 95% confidence interval = 1.33-3.26) compared with those with ASD. These findings demonstrate the need to assess these symptoms in all young children with developmental concerns to provide appropriate guidance to their families.

Acetate supplementation rescues social deficits and alters transcriptional regulation in prefrontal cortex of Shank3 deficient mice

BACKGROUND

The pathophysiology of autism spectrum disorder (ASD) involves genetic and environmental factors. Mounting evidence demonstrates a role for the gut microbiome in ASD, with signaling via short-chain fatty acids (SCFA) as one mechanism. Here, we utilize mice carrying deletion to exons 4-22 of Shank3 (Shank3KO) to model gene by microbiome interactions in ASD. We identify SCFA acetate as a mediator of gut-brain interactions and show acetate supplementation reverses social deficits concomitant with alterations to medial prefrontal cortex (mPFC) transcriptional regulation independent of microbiome status.

METHODS

Shank3KO and wild-type (Wt) littermates were divided into control, Antibiotic (Abx), Acetate and Abx + Acetate groups upon weaning. After six weeks, animals underwent behavioral testing. Molecular analysis including 16S and metagenomic sequencing, metabolomic and transcriptional profiling were conducted. Additionally, targeted serum metabolomic data from Phelan McDermid Syndrome (PMS) patients (who are heterozygous for the Shank3 gene) were leveraged to assess levels of SCFA's relative to ASD clinical measures.

RESULTS

Shank3KO mice were found to display social deficits, dysregulated gut microbiome and decreased cecal levels of acetate - effects exacerbated by Abx treatment. RNA-sequencing of mPFC showed unique gene expression signature induced by microbiome depletion in the Shank3KO mice. Oral treatment with acetate reverses social deficits and results in marked changes in gene expression enriched for synaptic signaling, pathways among others, even in Abx treated mice. Clinical data showed sex specific correlations between levels of acetate and hyperactivity scores.

CONCLUSION

These results suggest a key role for the gut microbiome and the neuroactive metabolite acetate in regulating ASD-like behaviors.

Exploring the intersection of autism spectrum disorder and eating disorders: understanding the unique challenges and treatment considerations for autistic women with eating disorders

PURPOSE OF REVIEW

Autistic women struggle with high levels of both autistic eating behaviours and disordered eating behaviours , which might make them particularly vulnerable to develop eating disorders. Research investigating the presence and characteristics of eating disorders in autistic women is however limited, as is research examining the role of autism in the treatment and recovery of an eating disorder in autistic women.

RECENT FINDINGS

The link between autism and eating disorders has mainly been investigated from the field of eating disorder research, with studies finding an overrepresentation of autism or autistic traits in eating disorders populations. Findings also suggest that autism or autistic traits are associated with a more serious presentation of the eating disorders, including a higher chance of a chronic course of the eating disorders. Most studies however lack comprehensive autism assessments, making it difficult to determine the actual prevalence of autism and its role in women with eating disorders.

SUMMARY

Autistic women with an eating disorder seem to suffer from more complex eating disorders and seem to not benefit from current treatment modalities. This could be partly related to specific autism characteristics such as sensory sensitivities, which are not being considered by current treatment protocols. Future research needs to shed light on what underlies the eating behaviours of autistic women with an eating disorder, in order to help to adapt current treatment modalities to meet the unique needs of these women.

GutMap: A New Interface for Analysing Regional Motility Patterns in ex vivo Mouse Gastrointestinal Preparations

Different regions of the gastrointestinal tract have specific functions and thus distinct motility patterns. Motility is primarily regulated by the enteric nervous system (ENS), an intrinsic network of neurons located within the gut wall. Under physiological conditions, the ENS is influenced by the central nervous system (CNS). However, by using ex vivo organ bath experiments, ENS regulation of gut motility can also be studied in the absence of CNS influences. The current technique enables the characterisation of small intestinal, caecal, and colonic motility patterns using an ex vivo organ bath and video imaging protocol. This approach is combined with the novel edge detection script GutMap, available in MATLAB, that functions across Windows and Mac platforms. Dissected intestinal segments are cannulated in an organ bath containing physiological saline with a camera mounted overhead. Video recordings of gut contractions are then converted to spatiotemporal heatmaps and analysed using the GutMap software interface. Using data analysed from the heatmaps, parameters of contractile patterns (including contraction propagation frequency and velocity as well as gut diameter) at baseline and in the presence of drugs/treatments/genetic mutations can be compared. Here, we studied motility patterns of female mice at baseline and in the presence of a nitric oxide synthase inhibitor (Nω-Nitro-L-arginine; NOLA) (nitric oxide being the main inhibitory neurotransmitter of gut motility) to showcase the application of GutMap. This technique is suitable for application to a broad range of animal models of clinical disorders to understand underlying biological pathways contributing to gastrointestinal dysfunction. Key features • Enhanced video imaging analysis of gut contractility in rodents using a novel software interface. • New edge detection algorithm to accurately contour curvatures of the gastrointestinal tract. • Allows for output of high-resolution spatiotemporal heatmaps across Windows and Mac platforms. • Edge detection and analysis method makes motility measurements accessible in different gut regions including the caecum and stomach.

Psychological, behavioural and biological factors associated with gastrointestinal symptoms in autistic adults and adults with autistic traits

LAY ABSTRACT

Little is known about factors related to the increased risk for gastrointestinal symptoms in adults with an autism spectrum disorder (ASD), while the negative impact of gastrointestinal symptoms is evident. Especially, the relationship between gastrointestinal symptoms and psychological, behavioural, and biological risk factors in adults with ASD (traits) is unclear. Autistic peer support workers and autism-advocates also emphasised the importance of identifying risk factors, because of the high prevalence of gastrointestinal problems in people with ASD. Therefore, our study investigated which psychological, behavioural, and biological factors are associated with gastrointestinal symptoms in adults with ASD or with autistic traits. We analysed data from 31,185 adults in the Dutch Lifelines Study. Questionnaires were used to evaluate the presence of an autism spectrum disorder diagnosis, autistic traits, gastrointestinal symptoms, psychological and behavioural factors. Biological factors were examined with body measurements. We found that not only adults with ASD but also adults with higher levels of autistic traits were at increased risk for gastrointestinal symptoms. Adults with ASD who experienced psychological problems (psychiatric problems, worse perceived health, chronic stress) had a higher risk for gastrointestinal symptoms than adults with ASD without these psychological problems. Moreover, adults with higher levels of autistic traits were less physically active, which was also associated with gastrointestinal symptoms. In conclusion, our study highlights the relevance of identifying psychological problems and evaluating physical activity when trying to help adults with ASD or autistic traits and gastrointestinal symptoms. This suggests that healthcare professionals should be more aware of behavioural and psychological risk factors when evaluating gastrointestinal symptoms in adults with ASD (traits).

Sleep Problems in Pediatric Disorders of Gut-Brain Interaction: A Systematic Review

OBJECTIVE

Disorders of gut-brain interaction (DGBIs) are common, and findings are mixed on rates of sleep problems (e.g., sleep quality) in pediatric populations. A clear understanding of sleep problems in pediatric DGBIs is needed as sleep challenges might negatively impact symptoms and prognoses. The aims of this systematic review are to (1) describe the prevalence and types of sleep problems in pediatric patients with DGBIs and examine differences by DGBI diagnosis and (2) examine the relationship among sleep problems and pain, mood, and functional outcomes in pediatric patients with DGBIs.

METHODS

We searched PubMed, PsycInfo, CINAHL, and Medline in June 2022; articles were included if they enrolled ≤19 years old with a DGBI, used a quantitative assessment of sleep problems, and were available in English. The Effective Public Health Practice Project Quality Assessment Tool for Quantitative Studies was used to assess study quality. We used a protocol to systematically pull and tabulate data across articles with quality assessment ratings.

RESULTS

Twenty-four articles with 110,864 participants across 9 countries were included, with most studies being of moderate to weak quality. Patients with DGBIs reported more sleep problems than healthy peers, and some research reviewed found that patients with IBS had more sleep problems than other DGBI diagnoses. Sleep problems in DGBIs were related to worse mood, pain, and functional outcomes.

CONCLUSION

Pediatric patients with DGBIs are experiencing sleep problems that can impact outcomes. Screening for sleep problems and targeted treatment is needed to best support these patients.

Development and Parasympathetic Regulation in Male and Female Adolescents with Autism Spectrum Disorder: A Two-Timepoint Longitudinal Study

Prolonged dysregulation of the autonomic nervous system (ANS) may increase propensity for physical or psychiatric illness. The current study examined differences in respiratory sinus arrhythmia (RSA) regulation in 215 adolescents with or without autism spectrum disorder (ASD) at Time 1 (T1; 10-13 years old) and 1 year later (Time 2; T2). Linear mixed effects models demonstrated lower RSA regulation in ASD, and a small interaction effect, showing blunted change in RSA from T1 to T2. Developmental differences in RSA regulation were particularly notable in females with ASD and those taking psychotropic medications. Results expand previous findings of reduced parasympathetic regulation in ASD by revealing a blunted developmental slope, indicating diagnostic differences may persist or worsen over time, particularly in females.

Gut Microbiome Dysbiosis as a Potential Risk Factor for Idiopathic Toe-Walking in Children: A Review

Idiopathic toe walking (ITW) occurs in about 5% of children. Orthopedic treatment of ITW is complicated by the lack of a known etiology. Only half of the conservative and surgical methods of treatment give a stable positive result of normalizing gait. Available data indicate that the disease is heterogeneous and multifactorial. Recently, some children with ITW have been found to have genetic variants of mutations that can lead to the development of toe walking. At the same time, some children show sensorimotor impairment, but these studies are very limited. Sensorimotor dysfunction could potentially arise from an imbalanced production of neurotransmitters that play a crucial role in motor control. Using the data obtained in the studies of several pathologies manifested by the association of sensory-motor dysfunction and intestinal dysbiosis, we attempt to substantiate the notion that malfunction of neurotransmitter production is caused by the imbalance of gut microbiota metabolites as a result of dysbiosis. This review delves into the exciting possibility of a connection between variations in the microbiome and ITW. The purpose of this review is to establish a strong theoretical foundation and highlight the benefits of further exploring the possible connection between alterations in the microbiome and TW for further studies of ITW etiology.

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.

Impaired cecal motility and secretion alongside expansion of gut-associated lymphoid tissue in the Nlgn3R451C mouse model of autism

Individuals with Autism Spectrum Disorder (ASD; autism) commonly present with gastrointestinal (GI) illness in addition to core diagnostic behavioural traits. The appendix, or cecum in mice, is important for GI homeostasis via its function as a key site for fermentation and a microbial reservoir. Even so, the role of the appendix and cecum in autism-associated GI symptoms remains uninvestigated. Here, we studied mice with an autism-associated missense mutation in the post-synaptic protein neuroligin-3 (Nlgn3R451C), which impacts brain and enteric neuronal activity. We assessed for changes in cecal motility using a tri-cannulation video-imaging approach in ex vivo preparations from wild-type and Nlgn3R451C mice. We investigated cecal permeability and neurally-evoked secretion in wild-type and Nlgn3R451C tissues using an Ussing chamber set-up. The number of cecal patches in fresh tissue samples were assessed and key immune populations including gut macrophages and dendritic cells were visualised using immunofluorescence. Nlgn3R451C mice displayed accelerated cecal motor complexes and reduced cecal weight in comparison to wildtype littermates. Nlgn3R451C mice also demonstrated reduced neurally-evoked cecal secretion in response to the nicotinic acetylcholine receptor agonist 1,1-dimethyl-4-phenylpiperazinium (DMPP), but permeability was unchanged. We observed an increase in the number of cecal patches in Nlgn3R451C mice, however the cellular morphologies of key immune populations studied were not significantly altered. We show that the R451C nervous system mutation leads to cecal dysmotility, impaired secretion, and neuro-immune alterations. Together, these results suggest that the R451C mutation disrupts the gut-brain axis with GI dysfunction in autism.

Relationships between Affect Recognition, Empathy, Alexithymia, and Co-Occurring Conditions in Autism

Prior studies show differences in empathy and affect-recognition ability between those with autism spectrum disorder (ASD) and typically developing (TD) individuals. Autistic individuals also exhibit increased behavioral, gastrointestinal, and sleep issues. In the current study, we explored the differences in empathy and affect recognition between the ASD and TD groups; and we investigated their associations with conditions co-occurring in ASD. A total of 54 TD and 56 ASD children (8-17 years) were included. As compared to the TD group, the ASD group showed lower scores for affect recognition and perspective taking (PT) and higher scores for personal distress (PD). Interestingly, results from hierarchical linear regressions suggested that disparities in the PD and PT between the groups were primarily attributable to attenuated levels of alexithymia, rather than being mediated by the presence of an autism diagnosis. Differences in affect-recognition ability, however, were mediated by both an autism diagnosis and alexithymia. We also found significant correlations between empathy and affect recognition and measures of related conditions common in ASD. Alexithymia, hence, contributes to difficulties in empathy while both alexithymia and autism are associated with affect-recognition ability in ASD. Additionally, the association between affect recognition and empathic ability with co-occurring conditions in ASD needs to be considered during assessments and interventions.

Association between prenatal antibiotic exposure and autism spectrum disorder among term births: A population-based cohort study

BACKGROUND

Prenatal antibiotic exposure induces changes in the maternal microbiome, which could influence the development of the infant's microbiome-gut-brain axis.

OBJECTIVES

We assessed whether prenatal antibiotic exposure is associated with an increased risk of autism spectrum disorder (ASD) in offspring born at term.

METHODS

This population-based retrospective cohort study included everyone who delivered a live singleton-term infant in British Columbia, Canada between April 2000 and December 2014. Exposure was defined as filling antibiotic prescriptions during pregnancy. The outcome was an ASD diagnosis from the British Columbia Autism Assessment Network, with a follow-up to December 2016. To examine the association among pregnant individuals treated for the same indication, we studied a sub-cohort diagnosed with urinary tract infections. Cox proportional hazards models were used to estimate unadjusted and adjusted hazard ratios (HR). The analysis was stratified by sex, trimester, cumulative duration of exposure, class of antibiotic, and mode of delivery. We ran a conditional logistic regression of discordant sibling pairs to control for unmeasured environmental and genetic confounding.

RESULTS

Of the 569,953 children included in the cohort, 8729 were diagnosed with ASD (1.5%) and 169,922 were exposed to prenatal antibiotics (29.8%). Prenatal antibiotic exposure was associated with an increased risk of ASD (HR 1.10, 95% confidence interval [CI] 1.05, 1.15), particularly for exposure during the first and second trimesters (HR 1.11, 95% CI 1.04, 1.18 and HR 1.09, 95% CI 1.03, 1.16, respectively), and exposure lasting ≥15 days (HR 1.13, 95% CI 1.04, 1.23). No sex differences were observed. The association was attenuated in the sibling analysis (adjusted odds ratio 1.04, 95% CI 0.92, 1.17).

CONCLUSIONS

Prenatal antibiotic exposure was associated with a small increase in the risk of ASD in offspring. Given the possibility of residual confounding, these results should not influence clinical decisions regarding antibiotic use during pregnancy.

Longitudinal relations between autistic-like features and functional somatic symptoms in adolescence

Abstract

Autistic-like features and functional somatic symptoms (FSS) frequently co-occur. It remains unknown how autistic-like features and FSS affect each other and develop throughout adolescence. This study examined reciprocal relations between autistic-like features and FSS in adolescence. Participants were 2772 adolescents (52.5% male) from the Tracking Adolescents’ Individual Lives Survey population and clinical cohort. Data from four waves were included, covering the ages between 11 and 19 years. Autistic-like features were measured using the Children’s Social Behavior Questionnaire. FSS were assessed using the Youth Self Report and Adult Self Report, respectively. Using the random intercept cross-lagged panel model, a stable positive, moderately strong between-persons association was found between autistic-like features and FSS. No within-persons reciprocal effects from wave to wave were observed. Secondary analyses revealed a consistent relation with FSS for three different domains of autistic-like features (social and communication behaviors, repetitive behaviors, and self-regulatory behaviors), and highly similar interrelations in a subsample of adolescents with a clinical autism spectrum disorder diagnosis. In conclusion, the co-occurrence between autistic-like features and FSS is stable throughout adolescence. Clinicians working with adolescents with autistic-like features should be alert to the presence FSS, and vice versa.

Prevalence of gastrointestinal symptoms in autism spectrum disorder: A meta-analysis

INTRODUCTION

A high prevalence of gastrointestinal (GI) symptoms has been described in children and adolescents with autism spectrum disorder (ASD). In addition, there is evidence that presence of GI symptoms is associated to greater severity of ASD. However, the frequency of GI symptoms in children and adolescents with ASD varies widely across studies, and their true prevalence is unknown. Therefore, the objective of this study was to estimate the prevalence of GI symptoms in children and adolescents with ASD.

MATERIAL AND METHOD

We conducted a meta-analysis following the PRISMA guidelines. We carried out a rapid systematic search for recent clinical and observational studies published from August 2012 in PubMed. The statistical analyses were performed with the software R.

RESULTS

Of 91 potentially eligible articles, only 8 met our inclusion criteria. The prevalence of GI symptoms ranged between 0% and 69%, with an estimated general prevalence of 33% (95% CI, 13%-57%), higher than that reported by a previous meta-analysis for the general paediatric population. This difference is even greater in the specific comparison of studies that applied the paediatric version of the ROME III questionnaire (QPGS-ROME III).

CONCLUSIONS

The results confirmed the hypothesis that there is a higher prevalence of functional GI symptoms in paediatric patients with ASD compared to their neurotypical peers.

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.