Gastrointestinal dysfunction in autism: parental report, clinical evaluation, and associated factors

An investigation of sleep problems, gastrointestinal symptoms, comorbid psychopathology and challenging behavior in children and adolescents with Down Syndrome

BACKGROUND

Down syndrome (DS) is one of the most common chromosomal abnormalities, and children with DS have increased risks of receiving diagnoses of specific comorbidities.

AIMS

This study aimed to assess the frequencies and relationships between sleep problems, gastrointestinal (GI) symptoms, comorbid psychopathology, and challenging behavior.

METHODS AND PROCEDURES

The Children's Sleep Habits Questionnaire, Gastrointestinal Symptom Inventory, Autism Spectrum Disorder-Comorbid for Children, and Behavior Problems Inventory-Short Form were completed by 123 parents of children and adolescents with DS.

OUTCOMES AND RESULTS

The frequency of GI symptoms was 74.8 %, with high frequencies also found for: sleep problems (100 %), challenging behavior (100 %), and moderate to severe levels of comorbid psychopathology (tantrum=80 %; repetitive behavior=63 %; avoidant behavior=82 %; worry/depressed=61 %; conduct behavior=100 %; over-eating=100 %; under-eating=100 %). A significant moderate correlation was found between total GI symptoms and self-injurious behavior frequency. Children who presented with abdominal pain engaged in self-injurious behavior more frequently than those with no abdominal pain.

CONCLUSIONS AND IMPLICATIONS

Findings indicated a high frequency of sleep problems, comorbid psychopathology, GI symptoms, and challenging behavior and demonstrated a relationship between GI symptoms and self-injurious behavior in children and adolescents with DS. This research illustrated the importance of investigating comorbid conditions in individuals with DS. WHAT THIS PAPER ADDS?: Down Syndrome (DS) is a genetic condition characterized by trisomy 21 and is a leading cause of intellectual disability worldwide. The prevalence of DS is commonly associated with advanced maternal age and is associated with multiple comorbid conditions. The current study aimed to investigate the frequency of and relationship between sleep problems, gastrointestinal symptoms, comorbid psychopathology, and challenging behavior in children and adolescents with DS. High-frequency levels were found for sleep problems (100 %), challenging behavior (100 %), gastrointestinal symptoms (74.8 %), and moderate to severe levels of the different comorbid psychopathologies (tantrum=80 %; repetitive behavior=63 %; avoidant behavior=82 %; worry/depressed=61 %; conduct behavior=100 %; over-eating=100 %; under-eating=100 %). Results indicated a significant difference in self-injurious behavior frequency between individuals who presented with abdominal pain and those who did not. This study is the first to investigate the relationship of multiple comorbid conditions in a sample of children with DS. This paper adds to the literature by demonstrating the frequency of a number of comorbid conditions in children and adolescents with DS. The paper also adds novel findings to the literature by investigating the relationships between comorbid conditions in this population. The findings of this paper highlighted the frequency and comorbidities that exist between gastrointestinal symptoms, sleep problems, comorbid psychopathology, and challenging behavior. Analyses indicated that those who presented with abdominal pain, engaged in self-injurious behavior more frequently. Sleep problems, gastrointestinal symptoms, comorbid psychopathology, and challenging behavior in children and adolescents with Down Syndrome.

Relationships between tryptophan-related gut metabolites, brain activity, and autism symptomatology

Gut microbial metabolites have been theorized to play a causative role in the pathophysiology of autism spectrum disorder (ASD). This hypothesis is based on results from mechanistic preclinical studies and several correlational studies showing differences in gut microbial composition between ASD subjects and neurotypical (NT) controls. However, alterations in how the human brain interacts with the gut microbiome in ASD have not been examined. In this cross-sectional, case-control observational study, fecal metabolomics, task-based functional magnetic resonance imaging (fMRI), and behavioral assessments were obtained from 43 ASD and 41 NT children aged 8-17. The fMRI tasks were based on socio-emotional and sensory paradigms that commonly show strong evoked brain differences in ASD participants. General linear models and mediational modeling were applied to examine the links between tryptophan metabolism and evoked brain activity and behavior. Results indicated that fecal levels of specific tryptophan-related metabolites were associated with: 1) brain activity atypicalities in regions previously implicated in ASD (i.e., insula and cingulate); and 2) ASD severity and symptomatology (i.e., ADOS scores, disgust propensity, and sensory sensitivities). Importantly, activity in the mid-insula and mid-cingulate significantly mediated relationships between the microbial tryptophan metabolites, indolelactate and tryptophan betaine, and ASD severity and disgust sensitivity. To our knowledge, this is the first study to elucidate how interactions between gut metabolites and brain activity may impact autism symptomatology, particularly in functional brain pathways associated with vagal and interoceptive/emotion processing.

Gut-brain barrier dysfunction bridge autistic-like behavior in mouse model of maternal separation stress: A behavioral, histopathological, and molecular study

Autism spectrum disorder (ASD) is a fast-growing neurodevelopmental disorder throughout the world. Experiencing early life stresses (ELS) like maternal separation (MS) is associated with autistic-like behaviors. It has been proposed that disturbance in the gut-brain axis-mediated psychiatric disorders following MS. The role of disruption in the integrity of gut-brain barrier in ASD remains unclear. Addressing this knowledge gap, in this study we aimed to investigate role of the gut-brain barrier integrity in mediating autistic-like behaviors in mouse models of MS stress. To do this, mice neonates are separated daily from their mothers from postnatal day (PND) 2 to PND 14 for 3 hours. During PND58-60, behavioral tests related to autistic-like behaviors including three-chamber sociability, shuttle box, and resident-intruder tests were performed. Then, prefrontal cortex (PFC), hippocampus, and colon samples were dissected out for histopathological and molecular evaluations. Results showed that MS is associated with impaired sociability and social preference indexes, aggressive behaviors, and impaired passive avoidance memory. The gene expression of CLDN1 decreased in the colon, and the gene expression of CLDN5, CLDN12, and MMP9 increased in the PFC of the MS mice. MS is associated with decrease in the diameter of CA1 and CA3 areas of the hippocampus. In addition, MS led to histopathological changes in the colon. We concluded that, probably, disturbance in the gut-brain barrier integrities mediated the autistic-like behavior in MS stress in mice.

Association Between Challenging Behaviour and Sleep Problems in Adults Enrolled in the Global Angelman Syndrome Registry

Angelman Syndrome (AS) is a rare genetic disorder that impacts 1:20,000 people. Challenging behaviour, such as severe injurious behaviour, aggression and frequent unprovoked episodes of laughter are a significant problem among adults with AS that adversely impacts an individual's quality of life. This study, for the first time, aims understand the characteristic of challenging behaviour, its frequency, and the factors associated with it in adults with AS. Data from participants with AS (N = 37; aged 18-46 years) registered with the Global Angelman Registry, were divided into challenging behaviour and non-challenging behaviour groups based on the presence or absence of 50% of the behaviours recorded in the registry. Descriptive statistics, chi-squared and t-test analysis were conducted to assess the impact of variables on challenging behaviour. Multiple regressions were conducted to investigate the predictors of challenging behaviour. 56% of the sample presented with challenging behaviour. Disorders of arousal, self-injury, behaviour dysregulation, repetitive behaviour, and the lack of physical therapy accounted for 59% of the variance of challenging behaviour in this population. It was found that challenging behaviour was very common in this population. A significant association was found between challenging behaviour and both sleep arousal and the lack of physical therapy. Sleep arousal and the lack of physical therapy were the key factors associated with challenging behaviour in this study. Targeted interventions are needed to decrease challenging behaviour and future research should focus on sleep interventions and increased opportunities for physical therapy.

Functional Gastrointestinal Symptoms in Children with Autism and ADHD: Profiles of Hair and Salivary Cortisol, Serum Leptin Concentrations and Externalizing/Internalizing Problems

BACKGROUND

Functional Gastrointestinal Disorders (FGIDs) present a higher prevalence in individuals with Neurodevelopmental Disorders (NDDs). The Stress System and the Gut-Brain axis (GBA) may mediate these relations. We aimed to assess the prevalence and profile of FGIDs in a clinical sample of children with Autism Spectrum Disorder (ASD) and Attention Deficit/Hyperactivity Disorder (ADHD) compared to typically developing children (TD) as well as to investigate possible relations between stress-related biomarkers and internalizing/externalizing problems in children with NDDS.

METHODS

In total, 120 children, aged between 4 and 12 years old, formed three groups (N = 40, each): ADHD, ASD and TD. Salivary cortisol, hair cortisol and serum leptin were measured.

RESULTS

The ASD group had more FGID problems than the TD group (p = 0.001). The ADHD and ASD groups had higher total internalizing/externalizing problems than the TD group (p < 0.0001, p < 0.0001, p = 0.005, respectively). Children with FGIDs showed more total, internalizing and externalizing problems compared to children without FGIDs (p < 0.0001, p < 0.0001, p = 0.041, respectively). The ADHD group showed lower AUCg values (p < 0.0001), while the hair cortisol was higher for the TD group (p < 0.0001).

CONCLUSION

In conclusion, children with NDDs had more FGID symptoms and present higher internalizing and externalizing problems. Children with ADHD and FGIDs had more internalizing problems compared to those without FGIDs. No differences in stress-related biomarkers were shown to differentiate children with NDDs with and without FGIDs. Future prospective studies including a greater number of children may elucidate the biological pathways linking these comorbidities.

Metabolic network analysis of pre-ASD newborns and 5-year-old children with autism spectrum disorder

Classical metabolomic and new metabolic network methods were used to study the developmental features of autism spectrum disorder (ASD) in newborns (n = 205) and 5-year-old children (n = 53). Eighty percent of the metabolic impact in ASD was caused by 14 shared biochemical pathways that led to decreased anti-inflammatory and antioxidant defenses, and to increased physiologic stress molecules like lactate, glycerol, cholesterol, and ceramides. CIRCOS plots and a new metabolic network parameter,V ° net, revealed differences in both the kind and degree of network connectivity. Of 50 biochemical pathways and 450 polar and lipid metabolites examined, the developmental regulation of the purine network was most changed. Purine network hub analysis revealed a 17-fold reversal in typically developing children. This purine network reversal did not occur in ASD. These results revealed previously unknown metabolic phenotypes, identified new developmental states of the metabolic correlation network, and underscored the role of mitochondrial functional changes, purine metabolism, and purinergic signaling in autism spectrum disorder.

Factors associated with sleep disturbances in children and adolescents with Angelman Syndrome

BACKGROUND

Angelman Syndrome (AS) is a rare genetic disorder characterised by hyperactivity, overexcitability, developmental delays, and lack of speech.

METHODS

This study used secondary data analysis to investigate sleep disturbances in children and adolescents (n = 212) who are enrolled in the Global Angelman Syndrome Registry. Participants were divided into two groups based on the presence or absence of sleep disturbance. The cut-off score of 40 on the Sleep Disturbance Scale for Children was used to indicate the presence or absence of sleep disturbances. Sleep disturbances and their association with co-occurring conditions were examined regarding challenging behaviour, language and communication, infancy history, gastrointestinal symptoms, and epilepsy. Multiple regression was then conducted to investigate possible predictors for sleep disturbances.

RESULTS

Children and adolescents with AS, with and without sleep disturbances, differed considerably regarding anxiety. Sleep disturbances were significantly associated with an ability to use spoken words and computerised communication devices, and anxiety was a predictor of sleep disturbances.

CONCLUSION

Future research is necessary to replicate this novel research, and to advance the clinical treatment of sleep disturbances in children and adolescents with AS.

Causal effects of gut microbiota on autism spectrum disorder: A two-sample mendelian randomization study

There is increasing evidence that alterations in gut microbiota (GM) composition are associated with autism spectrum disorder (ASD), but no reliable causal relationship has been established. Therefore, a 2-sample Mendelian randomization (MR) study was conducted to reveal a potential causal relationship between GM and ASD. Instrumental variables for 211 GM taxa were obtained from genome-wide association studies (GWAS) and Mendelian randomization studies to estimate their impact on ASD risk in the iPSYCH-PGC GWAS dataset (18,382 ASD cases and 27,969 controls). Inverse variance weighted (IVW) is the primary method for causality analysis, and several sensitivity analyses validate MR results. Among 211 GM taxa, IVW results confirmed that Tenericutes (P value = .0369), Mollicutes (P value = .0369), Negativicutes (P value = .0374), Bifidobacteriales (P value = .0389), Selenomonadales (P value = .0374), Bifidobacteriaceae (P value = .0389), Family XIII (P value = .0149), Prevotella7 (P value = .0215), Ruminococcaceae NK4A214 group (P value = .0205) were potential protective factors for ASD. Eisenbergiella (P value = .0159) was a possible risk factor for ASD. No evidence of heterogeneous, pleiotropic, or outlier single-nucleotide polymorphism was detected. Additionally, further sensitivity analysis verified the robustness of the above results. We confirm a potential causal relationship between certain gut microbes and ASD, providing new insights into how gut microbes mediate ASD. The association between them needs to be further explored and will provide new ideas for the prevention and treatment of ASD.

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.

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 early life exposome and autism risk: a role for the maternal microbiome?

Autism spectrum disorders (ASD) are highly heritable, heterogeneous neurodevelopmental disorders characterized by clinical presentation of atypical social, communicative, and repetitive behaviors. Over the past 25 years, hundreds of ASD risk genes have been identified. Many converge on key molecular pathways, from translational control to those regulating synaptic structure and function. Despite these advances, therapeutic approaches remain elusive. Emerging data unearthing the relationship between genetics, microbes, and immunity in ASD suggest an integrative physiology approach could be paramount to delivering therapeutic breakthroughs. Indeed, the advent of large-scale multi-OMIC data acquisition, analysis, and interpretation is yielding an increasingly mechanistic understanding of ASD and underlying risk factors, revealing how genetic susceptibility interacts with microbial genetics, metabolism, epigenetic (re)programming, and immunity to influence neurodevelopment and behavioral outcomes. It is now possible to foresee exciting advancements in the treatment of some forms of ASD that could markedly improve quality of life and productivity for autistic individuals. Here, we highlight recent work revealing how gene X maternal exposome interactions influence risk for ASD, with emphasis on the intrauterine environment and fetal neurodevelopment, host-microbe interactions, and the evolving therapeutic landscape for 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).

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.

Psychometric Properties of the Italian Version of the Toileting Habit Profile Questionnaire-Revised (THPQ-R) in Children with Autism Spectrum Disorder

INTRODUCTION

Children with autism spectrum disorder (ASD) often seem not to feel the need to go to the bathroom in whatever context they are in and may suffer from hypo-responsiveness. Recent studies show a correlation between sensory problems, constipation, and fecal incontinence in children. This requires an assessment tool to identify evacuation issues in children with sensory dysfunction. Therefore, the purpose of this study is to validate the Italian version of The Toileting Habit Profile Questionnaire-Revised (THPQ-R) in children with ASD.

METHODS

The inclusion criteria were a confirmed diagnosis of ASD and an age between 3 and 8 years old. The Toileting Habit Profile Questionnaire Revised (THPQ-R) was recently validated in the Italian language on a healthy population. The Italian version has 17 items with two alternative response options, frequently/always or never/rarely, based on how often the behavior occurs. The THPQ-R questionnaire is easy to administer, interpret, and manage. For concurrent validity, we used the Italian version of the Sensory Processing Measure and Sensory Processing Measure-Preschool.

RESULTS

For the THPQ-R validation, 43 participants were recruited. The internal consistency, reporting an α value of 0.763, showed that the THPQ-R was a very reliable scale. The THPQ-R appears to be correlated only with the domains "Social Participation T-point", "Hearing T-point", and "Planning and Ideas T-point". However, these correlations are not statistically significant. Conclusion: The THPQ-R highlights positive results regarding validity and reliability and shows a positive correlation between defecation disorders and social participation.

Relationship between child sleep problems in autism spectrum disorder and parent mental health and well-being

Sleep problems are a common comorbidity in children and adolescents with autism spectrum disorder (ASD). The aim of this study is to determine how sleep problems affect not only the child with ASD, but parents also. Parents of 409 children and adolescents with ASD completed the Children's Sleep Habits Questionnaire, Pittsburgh Sleep Quality Index, Parenting Stress Index-Short Form, World Health Organization Quality of Life Abbreviated Version (WHOQOL-BREF), Hospital Anxiety and Depression Scale, and the Multidimensional Scale of Perceived Social Support. The majority (86.6%) of parents presented with poor sleep. The majority (95.3%; n = 387) of children presented with sleep problems, while 4.7% (n = 22) did not have sleep problems. A cross-sectional within-subjects research design was utilised, with the following analyses conducted: Pearson correlations, chi-square tests, t-tests, and MANOVAs. Relationships were found between child sleep problems and parent sleep problems, specifically child parasomnias, sleep duration, night wakings, and sleep onset delay. Parents of children with sleep problems experienced more parenting stress, specifically on the Difficult Child and Parent-Child Dysfunctional Interaction subscales of the Parenting Stress Index-Short Form. Parents of children and adolescents with sleep problems had significantly higher levels of anxiety and depression than parents of children and adolescents who did not have sleep problems. A relationship between sleep problems and lower quality of life was found. Parents of children with sleep problems received significantly lower scores on the WHOQOL-BREF domains of Physical Health, Psychological and Environment than parents of children without sleep problems. There was no significant difference found between parents of children with or without sleep problems on perceived social support. The current study demonstrated how child sleep affects parental well-being. While sleep problems are one comorbid condition in ASD, future research is needed to determine the impact of other comorbidities in parents of children and adolescents with ASD.

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.

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.

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.

Bee Pollen and Probiotics' Potential to Protect and Treat Intestinal Permeability in Propionic Acid-Induced Rodent Model of Autism

Rodent models may help investigations on the possible link between autism spectrum disorder (ASD) and gut microbiota since autistic patients frequently manifested gastrointestinal troubles as co-morbidities. Thirty young male rats were divided into five groups: Group 1 serves as control; Group 2, bee pollen and probiotic-treated; and Group 3, propionic acid (PPA)-induced rodent model of autism; Group 4 and Group 5, the protective and therapeutic groups were given bee pollen and probiotic combination treatment either before or after the neurotoxic dose of PPA, respectively. Serum occludin, zonulin, lipid peroxides (MDA), glutathione (GSH), glutathione-S-transferase (GST), glutathione peroxidase (GPX), catalase, and gut microbial composition were assessed in all investigated groups. Recorded data clearly indicated the marked elevation in serum occludin (1.23 ± 0.15 ng/mL) and zonulin (1.91 ± 0.13 ng/mL) levels as potent biomarkers of leaky gut in the PPA- treated rats while both were normalized to bee pollen/probiotic-treated rats. Similarly, the high significant decrease in catalase (3.55 ± 0.34 U/dL), GSH (39.68 ± 3.72 µg/mL), GST (29.85 ± 2.18 U/mL), and GPX (13.39 ± 1.54 U/mL) concomitant with a highly significant increase in MDA (3.41 ± 0.12 µmoles/mL) as a marker of oxidative stress was also observed in PPA-treated animals. Interestingly, combined bee pollen/probiotic treatments demonstrated remarkable amelioration of the five studied oxidative stress variables as well as the fecal microbial composition. Overall, our findings demonstrated a new approach to the beneficial use of bee pollen and probiotic combination as a therapeutic intervention strategy to relieve neurotoxic effects of PPA, a short-chain fatty acid linked to the pathoetiology of autism.

Intestinal Barrier Dysfunction and Microbiota–Gut–Brain Axis: Possible Implications in the Pathogenesis and Treatment of Autism Spectrum Disorder

Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder with multifactorial etiology, characterized by impairment in two main functional areas: (1) communication and social interactions, and (2) skills, interests and activities. ASD patients often suffer from gastrointestinal symptoms associated with dysbiotic states and a “leaky gut.” A key role in the pathogenesis of ASD has been attributed to the gut microbiota, as it influences central nervous system development and neuropsychological and gastrointestinal homeostasis through the microbiota–gut–brain axis. A state of dysbiosis with a reduction in the Bacteroidetes/Firmicutes ratio and Bacteroidetes level and other imbalances is common in ASD. In recent decades, many authors have tried to study and identify the microbial signature of ASD through in vivo and ex vivo studies. In this regard, the advent of metabolomics has also been of great help. Based on these data, several therapeutic strategies, primarily the use of probiotics, are investigated to improve the symptoms of ASD through the modulation of the microbiota. However, although the results are promising, the heterogeneity of the studies precludes concrete evidence. The aim of this review is to explore the role of intestinal barrier dysfunction, the gut–brain axis and microbiota alterations in ASD and the possible role of probiotic supplementation in these patients.

A review of probiotics in the treatment of autism spectrum disorders: Perspectives from the gut–brain axis

Autism spectrum disorders (ASD) are a class of neurodevelopmental conditions with a large societal impact. Despite existing evidence suggesting a link between ASD pathogenesis and gut–brain axis dysregulation, there is no systematic review of the treatment of probiotics on ASD and its associated gastrointestinal abnormalities based on the gut–brain axis. Therefore, we performed an analysis for ASD based on preclinical and clinical research to give a comprehensive synthesis of published evidence of a potential mechanism for ASD. On the one hand, this review aims to elucidate the link between gastrointestinal abnormalities and ASD. Accordingly, we discuss gut microbiota dysbiosis regarding gut–brain axis dysfunction. On the other hand, this review suggests that probiotic administration to regulate the gut–brain axis might improve gastrointestinal symptoms, restore ASD-related behavioral symptoms, restore gut microbiota composition, reduce inflammation, and restore intestinal barrier function in human and animal models. This review suggests that targeting the microbiota through agents such as probiotics may represent an approach for treating subsets of individuals with ASD.

Evaluation of Chronic Constipation in Children With Autism Spectrum Disorder

OBJECTIVES

Chronic constipation occurs frequently in children with autism spectrum disorder (ASD). The primary objective was to determine whether chronic constipation is associated with a higher rate of abnormal colonic motor activity in ASD children than in non-ASD children. A secondary goal was to determine if clinical variables could identify children with ASD at risk for possessing abnormal colonic motility.

METHODS

A retrospective, propensity-matched, case-control study compared colonic manometry (CM) of an ASD cohort and non-ASD controls with chronic constipation. Clinical variables were evaluated as potential predictors for abnormal colonic motility.

RESULTS

Fifty-six patients with ASD and 123 controls without the diagnosis of ASD who underwent CM were included. Propensity score resulted in 35 matched cohorts of ASD and controls. The rate of abnormal CM findings between ASD and matched controls (24% vs 20%, P = 0.78) did not differ significantly. A prediction model of abnormal CM that included ASD diagnosis, duration of constipation, and soiling achieved a sensitivity of 0.94 and specificity of 0.65. The risk for abnormal colonic motility increased 11% for every 1-year increase in duration of constipation. Odds for abnormal motility were 30 times higher in ASD children with soiling than controls with soiling (P < 0.0001).

CONCLUSIONS

Chronic constipation does not appear to be associated with a higher rate of abnormal colonic motility in children with ASD. Clinical information of disease duration and presence of soiling due to constipation show promise in identifying patients with ASD at a greater risk for abnormal colonic motility.

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.

Disorders of Gut-Brain Interaction in a National Cohort of Children With Down Syndrome

Background/Aims

Disorders of brain-gut interaction (DGBIs) are present in adults and children around the world. Down syndrome (DS) is the most common chromosomal condition in humans. While DS has associations with many organic medical conditions, the frequency of DGBIs in children and adolescents with DS has not previously been studied. We assess the rate of DGBIs in children and adolescents 4-18 years of age with DS in the United States using the Rome IV criteria by caregiver report.

Methods

This is a cross-sectional national survey study in which caregivers (n = 114) of children with DS completed an online survey about their child's gastrointestinal symptoms and quality of life (QoL).

Results

Using the Rome IV parent-report diagnostic questionnaire, 51.8% of children met symptom-based criteria for at least 1 DGBI. Functional constipation (36.0%) and irritable bowel syndrome (14.9%) were the most common disorders identified. QoL was lower in children with at least 1 disorder as compared to children who did not meet criteria for any disorders (mean QoL = 62.3 vs mean QoL = 72.9, P < 0.001). Almost all children with DS and concomitant autism (87.5%) had at least 1 DGBI.

Conclusions

DGBIs are common in children with DS and are associated with diminished QoL.

Leaky Gut Plays a Critical Role in the Pathophysiology of Autism in Mice by Activating the Lipopolysaccharide-Mediated Toll-Like Receptor 4–Myeloid Differentiation Factor 88–Nuclear Factor Kappa B Signaling Pathway

Increased intestinal barrier permeability, leaky gut, has been reported in patients with autism. However, its contribution to the development of autism has not been determined. We selected dextran sulfate sodium (DSS) to disrupt and metformin to repair the intestinal barrier in BTBR T+tf/J autistic mice to test this hypothesis. DSS treatment resulted in a decreased affinity for social proximity; however, autistic behaviors in mice were improved after the administration of metformin. We found an increased affinity for social proximity/social memory and decreased repetitive and anxiety-related behaviors. The concentration of lipopolysaccharides in blood decreased after the administration of metformin. The expression levels of the key molecules in the toll-like receptor 4 (TLR4)–myeloid differentiation factor 88 (MyD88)–nuclear factor kappa B (NF-κB) pathway and their downstream inflammatory cytokines in the cerebral cortex were both repressed. Thus, “leaky gut” could be a trigger for the development of autism via activation of the lipopolysaccharide-mediated TLR4–MyD88–NF-κB pathway.

Altered gut microbiota correlates with behavioral problems but not gastrointestinal symptoms in individuals with autism

BACKGROUND

Despite inconsistent results across studies, emerging evidence suggests that the microbial micro-environment may be associated with autism spectrum disorder (ASD). Geographical and cultural factors highly impact microbial profiles, and there is a shortage of data from East Asian populations. This study aimed to comprehensively characterize microbial profiles in an East Asian sample and explore whether gut microbiota contributes to clinical symptoms, emotional/behavioral problems, and GI symptoms in ASD.

METHODS

We assessed 82 boys and young men with ASD and 31 typically developing controls (TDC), aged 6-25 years. We analyzed the stool sample of all participants with 16S V3-V4 rRNA sequencing and correlated its profile with GI symptoms, autistic symptoms, and emotional/behavioral problems.

RESULTS

Autistic individuals, compared to TDC, had worse GI symptoms. There were no group differences in alpha diversity of species richness estimates (Shannon-wiener and Simpson diversity indices). Participants with ASD had an increased relative abundance of Fusobacterium, Ruminococcus torques group (at the genus level), and Bacteroides plebeius DSM 17135 (at the species level), while a decreased relative abundance of Ruminococcaceae UCG 013, Ervsipelotrichaceae UCG 003, Parasutterella, Clostridium sensu stricto 1, Turicibacter (at the genus level), and Clostridium spiroforme DSM 1552 and Intestinimonas butyriciproducens (at the species level). Altered taxonomic diversity in ASD significantly correlated with autistic symptoms, thought problems, delinquent behaviors, self dysregulation, and somatic complaints. We did not find an association between gut symptoms and gut microbial dysbiosis.

CONCLUSIONS

Our findings suggest that altered microbiota are associated with behavioral phenotypes but not GI symptoms in ASD. The function of the identified microbial profiles mainly involves the immune pathway, supporting the hypothesis of a complex relationship between altered microbiome, immune dysregulation, and ASD that may advance the discovery of molecular biomarkers for ASD.

Association between early and current gastro-intestinal symptoms and co-morbidities in children and adolescents with Angelman syndrome

BACKGROUND

Angelman syndrome (AS) is a neurogenetic disorder that causes severe intellectual disability, expressive language deficits, motor impairment, ataxia, sleep problems, epileptic seizures and a happy disposition. People with AS frequently experience gastrointestinal (GI) symptoms.

METHOD

This study used data from the Global Angelman Syndrome Registry to explore the relationship between early and current GI symptoms and co-morbidity in children and adolescents with AS (n = 173). Two groups that experienced a high (n = 91) and a low (n = 82) frequency of GI symptoms were examined in relation to feeding and GI history in infancy, sleep and toileting problems, levels of language and communication and challenging behaviours. Predictors of GI symptoms were then investigated using a series of logistic regressions.

RESULTS

This analysis found that constipation and gastroesophageal reflux affected 84% and 64%, of the sample, respectively. The high frequency of GI symptoms were significantly associated with: 'refusal to nurse', 'vomiting', 'arching', 'difficulty gaining weight', gastroesophageal reflux, 'solid food transition', frequency of night-time urinary continence and sleep hyperhidrosis during infancy. GI symptoms were not significantly associated with sleep, toileting, language or challenging behaviours. Significant predictors of high frequency GI symptoms were gastroesophageal reflux and sleep hyperhidrosis.

CONCLUSIONS

Future research needs to investigate the association between AS and GI co-morbidity in adults with AS.

Vitamin/mineral/micronutrient supplement for autism spectrum disorders: a research survey

Background

Vitamin and mineral supplements are widely used by children and adults diagnosed with autism spectrum disorder (ASD). Several studies have reported benefits of such supplements in resolving nutritional deficiencies, treating various metabolic problems and improving symptoms and overall quality of life.

Methods

This research survey collected evaluations from 161 people about the effectiveness of ANRC-Essentials Plus (ANRC-EP), a vitamin/mineral/micronutrient supplement designed for children and adults with autism. Although this was an open-label survey, results were compared with a three-month randomized double-blind placebo-controlled study of an earlier version of the supplement. Evaluations included the Parent Global Impressions of Autism (PGIA) and the Overall Benefit/Adverse Effect scale of the National Survey on Treatment Effectiveness for Autism (NSTEA).

Results

The participants reported substantially higher Average PGIA Scores than the placebo group in a similar previous study, with an estimated effect size of 0.66. Based on the NSTEA questionnaire, 73% of participants rated the Overall Benefit as Moderate, Good, or Great, with scores that were substantially higher than the NSTEA study found for multi-vitamins, the average of 58 nutraceuticals, and the average of 28 psychiatric and seizure medications. The Overall Adverse Effect score was low (0.25/3.0), similar or slightly higher than other nutraceuticals, and much lower than the average of 28 psychiatric and seizure medications (0.9/3.0). Sub-analysis found that the Overall Benefit of ANRC-EP was not significantly affected by gender, age, autism severity, diet quality, self-limited diet, use of psychiatric or seizure medications, dosage, developmental history, intellectual disability, or seizures. This indicates that ANRC-EP may be beneficial for a wide range of children and adults with ASD.

A limitation of this study is the retrospective nature of the survey, and that participants who had good benefits were more likely to respond.

Conclusions

This study found that ANRC-EP had significant benefits for a wide range of symptoms, and low adverse effects.

Gastrointestinal symptoms have a minor impact on autism spectrum disorder and associations with gut microbiota and short-chain fatty acids

Children with autism spectrum disorder (ASD) experience gastrointestinal (GI) issues more frequently and severely than children who are typically developing (TD). The connections between gastrointestinal problems, microbiota, and short-chain fatty acids (SCFAs) in ASD are still being debated. We enrolled 90 children, 45 of whom were diagnosed with ASD, and examined the impact of GI disorders on ASD. The six-item GI Severity Index questionnaire was used to evaluate gastrointestinal symptoms, while the Social Responsiveness Scale was used to evaluate autism symptoms. Further, the Children’s Sleep Habits Questionnaire and the Children’s Eating Behavior Questionnaire are used to assess sleep and eating disorders in children. We assessed fecal microbiota by 16S rRNA gene sequencing, and SCFA concentrations by gas chromatography/mass spectrometry. The results revealed that children with ASD exhibited a high rate of gastrointestinal issues (78%), as well as higher rates of social impairment and poor sleeping habits, compared to TD children. However, GI disturbances have a minor impact on autism. In addition, the levels of propionic acid, butyric acid, and valeric acid were significantly higher in the ASD group. Besides, the ASD, TD, and GI subgroups possessed distinct microbiome profiles. These findings suggest that gastrointestinal disturbances have no discernible effect on the core symptoms of autism. Although autism may not cause an increase in GI symptoms directly, alterations in metabolites, such as SCFAs, may cause GI symptoms.

Maternal obesity, diabetes, preeclampsia, and asthma during pregnancy and likelihood of autism spectrum disorder with gastrointestinal disturbances in offspring

LAY ABSTRACT

Autism spectrum disorder is heterogeneous and often accompanied by co-occurring conditions. Previous studies have shown that maternal health conditions during pregnancy including obesity, diabetes, preeclampsia, and asthma were associated with increased likelihood of autism. However, little has been done examining the likelihood associated with autism with co-occurring conditions. This study assessed these maternal health conditions in relationship to autism and gastrointestinal disturbances, a common co-occurring condition in children diagnosed with autism. Data included 308,536 mother-child pairs from one integrated health care system with comprehensive electronic medical records. Among the study cohort, 5,131 (1.7%) children had a diagnosis of autism by age 5. Gastrointestinal disturbances were present in 35.4% of children diagnosed with autism and 25.1% of children without autism diagnoses. Our results showed that each of the four maternal health conditions during pregnancy was associated with increased likelihood of gastrointestinal disturbances, autism without gastrointestinal disturbances, and autism with gastrointestinal disturbances. For all four maternal health conditions, the association was greatest for likelihood of autism with gastrointestinal disturbances. Given that children diagnosed with autism are more likely to have gastrointestinal disturbances and over 80% of gastrointestinal disturbances in this cohort were diagnosed prior to autism diagnosis, this study suggests that there may be common biological pathways between autism and gastrointestinal disturbances impacted by these maternal exposures. Future studies are warranted to assess associations between different exposures and autism with other co-occurring conditions to increase our understanding of autism heterogeneity.

Relationships between challenging behavior and gastrointestinal symptoms, sleep problems, and internalizing and externalizing symptoms in children and adolescents with Angelman syndrome

BACKGROUND

Angelman syndrome (AS), is a rare genetic disorder. This study investigated the relationship between parent-reported comorbid symptoms including gastrointestinal symptoms, sleep problems, internalizing symptoms, and behavior problems in children and adolescents with AS.

METHOD

Parents of 98 children and adolescents with AS completed the Gastrointestinal Symptom Inventory, Children's Sleep Habits Questionnaire, Child Behavior Checklist, Social Communication Questionnaire, and the Behavior Problem Inventory-Short Form. Data were analyzed using descriptive statistics, Pearson's correlation coefficients, and hierarchical multiple regressions.

RESULTS

There was a high frequency of GI symptoms (99%), sleep problems (95.9%), challenging behavior (98%), internalizing symptoms (38%), and 72.4% of children and adolescents presented with ASD symptoms. Self-injurious behavior (SIB), aggressive/destructive behavior, and the frequency of stereotyped behavior positively correlated with GI symptoms and sleep problems and it was moderately negatively associated with age. Internalizing symptoms and age were positively associated with SIB. Aggression was significantly related to gender, but not the presence of ASD symptoms.

CONCLUSIONS

Findings highlight the relationships between comorbid conditions. They may lead to a deeper understanding of how comorbidities present in children and adolescents with Angelman Syndrome.

The presence of a neurodiverse disorder is associated with increased use of antegrade enema therapy in children with severe constipation: A study from the Pediatric Colorectal and Pelvic Learning Consortium (PCPLC)

INTRODUCTION

Children with severe constipation and a neurodiverse disorder (Autism and/or developmental delay) represent a challenging bowel management group. Treatment outcomes with laxative or enema therapy remain limited and are often complicated by patient/caregiver compliance. We hypothesized that children with neurodiverse disorders and severe constipation would benefit from a bowel management program (BMP) that includes early use of antegrade enemas.

MATERIALS AND METHODS

Children requiring BMP in the Pediatric Colorectal and Pelvic Learning Consortium (PCPLC) registry with diagnosis of constipation and/or constipation with pseudo-incontinence were reviewed. Those with Hirschsprung disease and/or Anorectal Malformation were excluded. BMP needs in patients with a neurodiverse diagnosis were compared to those without to evaluate differences in BMP's.

RESULTS

372 patients requiring a BMP were identified. 95 patients (58 autism spectrum, 54 developmental delay) were neurodiverse, and 277 patients were not. Neurodiverse patients had a higher prevalence of enema therapy 62.1% (59/95) vs. 54.9% (152/273) and use of antegrade enema therapy 33.7% (32/95) vs. 21.2% (58/273), p = 0.126. Neurodiverse patients were older 37.9% (36/95) > 12 years vs. 23.1% (63/273), p = 0.001 and 47.6% (10/21) were changed from laxative to enema therapy over time. 80% (8/10) of those changed from laxatives to enemas used antegrade therapy. 67.3% (35/52) of neurodiverse patients followed over time were on enema therapy at the most recent visit with 80% (28/35) requiring antegrade therapy.

CONCLUSION

A large portion of patients with a neurodiverse disorder who fail laxative therapy use antegrade enemas to achieve effective bowel management. Early consideration of an antegrade conduit may simplify treatment in this group of children.

LEVEL OF EVIDENCE

III.

Oxytocin and serotonin in the modulation of neural function: Neurobiological underpinnings of autism-related behavior

Autism spectrum disorders (ASD) is a group of generalized neurodevelopmental disorders. Its main clinical features are social communication disorder and repetitive stereotyped behavioral interest. The abnormal structure and function of brain network is the basis of social dysfunction and stereotyped performance in patients with autism spectrum disorder. The number of patients diagnosed with ASD has increased year by year, but there is a lack of effective intervention and treatment. Oxytocin has been revealed to effectively improve social cognitive function and significantly improve the social information processing ability, empathy ability and social communication ability of ASD patients. The change of serotonin level also been reported affecting the development of brain and causes ASD-like behavioral abnormalities, such as anxiety, depression like behavior, stereotyped behavior. Present review will focus on the research progress of serotonin and oxytocin in the pathogenesis, brain circuit changes and treatment of autism. Revealing the regulatory effect and neural mechanism of serotonin and oxytocin on patients with ASD is not only conducive to a deeper comprehension of the pathogenesis of ASD, but also has vital clinical significance.

Gut Microbiome and Brain: Scope and Perspectives

Editorial.

The Co-Occurrence of Autism Spectrum Disorder and Cerebral Palsy and Associated Comorbid Conditions in Children and Adolescents

BACKGROUND

Comorbidity is the co-occurrence of two or more disorders in the same person.

AIM

This study investigated the frequency of comorbid conditions, in children and adolescents, with autism spectrum disorder (ASD), cerebral palsy (CP), and a comorbid diagnosis of ASD and CP.

METHOD

Ninety-six children and adolescents with ASD, CP, and both ASD and CP aged between 4 and 18 years participated in this study. Parents completed the Gastrointestinal Symptom Inventory, Children's Sleep Habits Questionnaire, Child Behavior Checklist, Social Communication Questionnaire, and the Vineland Adaptive Behavior Scales.

RESULTS

Results of ANOVA analyses revealed significant group differences in sleep problems, social communication difficulties, and adaptive behavior. Regression analysis found that the presence of an intellectual disability significantly predicted levels of adaptive behavior.

CONCLUSION

This research demonstrated the importance of studying comorbidities in children and adolescents with CP alone, ASD alone, and combined ASD and CP.

Comparing the Gut Microbiome in Autism and Preclinical Models: A Systematic Review

Many individuals diagnosed with autism spectrum disorder (ASD) experience gastrointestinal (GI) dysfunction and show microbial dysbiosis. Variation in gut microbial populations is associated with increased risk for GI symptoms such as chronic constipation and diarrhoea, which decrease quality of life. Several preclinical models of autism also demonstrate microbial dysbiosis. Given that much pre-clinical research is conducted in mouse models, it is important to understand the similarities and differences between the gut microbiome in humans and these models in the context of autism. We conducted a systematic review of the literature using PubMed, ProQuest and Scopus databases to compare microbiome profiles of patients with autism and transgenic (NL3^R451C, Shank3 KO, 15q dup), phenotype-first (BTBR) and environmental (Poly I:C, Maternal Inflammation Activation (MIA), valproate) mouse models of autism. Overall, we report changes in fecal microbial communities relevant to ASD based on both clinical and preclinical studies. Here, we identify an overlapping cluster of genera that are modified in both fecal samples from individuals with ASD and mouse models of autism. Specifically, we describe an increased abundance of Bilophila, Clostridium, Dorea and Lactobacillus and a decrease in Blautia genera in both humans and rodents relevant to this disorder. Studies in both humans and mice highlighted multidirectional changes in abundance (i.e. in some cases increased abundance whereas other reports showed decreases) for several genera including Akkermansia, Bacteroides, Bifidobacterium, Parabacteroides and Prevotella, suggesting that these genera may be susceptible to modification in autism. Identification of these microbial profiles may assist in characterising underlying biological mechanisms involving host-microbe interactions and provide future therapeutic targets for improving gut health in autism.

Gut Microbiota Ecology and Inferred Functions in Children With ASD Compared to Neurotypical Subjects

Autism spectrum disorders (ASDs) is a multifactorial neurodevelopmental disorder. The communication between the gastrointestinal (GI) tract and the central nervous system seems driven by gut microbiota (GM). Herein, we provide GM profiling, considering GI functional symptoms, neurological impairment, and dietary habits. Forty-one and 35 fecal samples collected from ASD and neurotypical children (CTRLs), respectively, (age range, 3–15 years) were analyzed by 16S targeted-metagenomics (the V3–V4 region) and inflammation and permeability markers (i.e., sIgA, zonulin lysozyme), and then correlated with subjects’ metadata. Our ASD cohort was characterized as follows: 30/41 (73%) with GI functional symptoms; 24/41 (58%) picky eaters (PEs), with one or more dietary needs, including 10/41 (24%) with food selectivity (FS); 36/41 (88%) presenting high and medium autism severity symptoms (HMASSs). Among the cohort with GI symptoms, 28/30 (93%) showed HMASSs, 17/30 (57%) were picky eaters and only 8/30 (27%) with food selectivity. The remaining 11/41 (27%) ASDs without GI symptoms that were characterized by HMASS for 8/11 (72%) and 7/11 (63%) were picky eaters. GM ecology was investigated for the overall ASD cohort versus CTRLs; ASDs with GI and without GI, respectively, versus CTRLs; ASD with GI versus ASD without GI; ASDs with HMASS versus low ASSs; PEs versus no-PEs; and FS versus absence of FS. In particular, the GM of ASDs, compared to CTRLs, was characterized by the increase of Proteobacteria, Bacteroidetes, Rikenellaceae, Pasteurellaceae, Klebsiella, Bacteroides, Roseburia, Lactobacillus, Prevotella, Sutterella, Staphylococcus, and Haemophilus. Moreover, Sutterella, Roseburia and Fusobacterium were associated to ASD with GI symptoms compared to CTRLs. Interestingly, ASD with GI symptoms showed higher value of zonulin and lower levels of lysozyme, which were also characterized by differentially expressed predicted functional pathways. Multiple machine learning models classified correctly 80% overall ASDs, compared with CTRLs, based on Bacteroides, Lactobacillus, Prevotella, Staphylococcus, Sutterella, and Haemophilus features. In conclusion, in our patient cohort, regardless of the evaluation of many factors potentially modulating the GM profile, the major phenotypic determinant affecting the GM was represented by GI hallmarks and patients’ age.

Pediatric neuropsychiatric syndromes associated with infection and microbiome alterations: clinical findings, possible role of the mucosal epithelium, and strategies for the development of new animal models

INTRODUCTION

: Subsets of pediatric obsessive-compulsive disorder (OCD) and autism spectrum disorder (ASD) respectively have been associated with respiratory tract infections and alterations in the intestinal microbiome. Pediatric Acute-onset Neuropsychiatric Syndromes (PANS) refers to the sudden onset of neuropsychiatric symptoms that are triggered by several different infectious and non-infectious factors. Clinical studies and animal modeling are consistent with the proposal that inflammation plays an important etiological role in PANS, as well as in ASD associated with gut dysbiosis.

AREAS COVERED

The authors provide an overview of clinical studies of PANS and ASD associated with gastrointestinal symptoms, as well as the current strategies for studying these syndromes in rodent models. Finally, the authors highlight similarities between these syndromes that may provide clues to common etiological mechanisms.

EXPERT OPINION

Although data from existing animal models are consistent with an important role for anti-neuronal antibodies in PANS triggered by GAS infection, we lack models for identifying pathophysiological mechanisms of PANS associated with other infectious and non-infectious triggers. The authors propose a strategy for developing such models that incorporates known vulnerability and triggering factors for PANS into the modeling process. This novel strategy should expand our understanding of the pathophysiology of PANS, as well as facilitate the development of new pharmacological treatments for PANS and related syndromes.

Attention-Deficit/Hyperactivity Disorder Symptoms, Gastrointestinal Symptoms, Sleep Problems, Challenging Behavior, Adaptive Behavior, and Quality of Life in Children and Adolescents with Autism Spectrum Disorder

This study investigated the relationship between sleep, gastrointestinal symptoms, challenging behavior, adaptive behavior, and quality of life between children and adolescents with autism spectrum disorder (ASD), with and without attention-deficit/hyperactivity disorder (AD/HD) symptoms. Parents of 118 children and adolescents with ASD completed the Conners Early Childhood Rating Scale-Parent Short Form or the Conners 3-Parent Short Form, Children's Sleep Habits Questionnaire, Gastrointestinal Symptom Inventory, Behavior Problems Inventory-Short Form, Pediatric Quality of Life Inventory and the Vineland Adaptive Behavior Scales, Second Edition. The ASD group and the ASD with AD/HD groups differed significantly in sleep problems, gastrointestinal symptoms, and quality of life. Regressions indicated that AD/HD symptoms accounted for a small proportion of the variance for the differences in sleep problems and quality of life. AD/HD symptoms contribute to the complex needs of individuals with ASD. Research is necessary to investigate how these symptoms exacerbate comorbidities.

Managing constipation in children with ASD - A challenge worth tackling

Autism Spectrum disorder (ASD) is well known to be associated with significantly high rates of gastrointestinal problems, constipation being common among them, imposing a significant burden on child and the family. On account of multiple underlying factors, both diagnosis and subsequent management of constipation in children with ASD are much more challenging as compared to managing constipation in 'neurotypical' children. Associated higher rate of presentation to the hospital emergency and subsequent hospital admission rates add to the burden. Hence, there is a need for recognizing constipation as a problem in children with ASD. This review summarizes optimization of its management by adopting a multidisciplinary holistic approach to achieve good outcomes and enhance the quality of life for the child and the family.

Enteric Nervous System: The Bridge Between the Gut Microbiota and Neurological Disorders

The gastrointestinal (GI) tract plays an essential role in food digestion, absorption, and the mucosal immune system; it is also inhabited by a huge range of microbes. The GI tract is densely innervated by a network of 200–600 million neurons that comprise the enteric nervous system (ENS). This system cooperates with intestinal microbes, the intestinal immune system, and endocrine systems; it forms a complex network that is required to maintain a stable intestinal microenvironment. Understanding how gut microbes influence the ENS and central nervous system (CNS) has been a significant research subject over the past decade. Moreover, accumulating evidence from animal and clinical studies has revealed that gut microbiota play important roles in various neurological diseases. However, the causal relationship between microbial changes and neurological disorders currently remains unproven. This review aims to summarize the possible contributions of GI microbiota to the ENS and CNS. It also provides new insights into furthering our current understanding of neurological disorders.

Gastrointestinal Symptoms in Autism Spectrum Disorder: A Systematic Review

This systematic review aims to offer an updated understanding of the relationship between gastrointestinal symptoms (GIS) and autism spectrum disorder (ASD) in children and adolescents. The databases PsycINFO, Medline, Cinahl, and ERIC were searched using keywords, and relevant literature was hand-searched. Papers (n = 3319) were systematically screened and deemed eligible if they were empirical studies published in English since 2014 and measured the GIS of individuals with ASD who were under 18 years old. Thirty studies were included in the final review. The study findings were synthesized under eight themes, including the prevalence and nature of GIS and their relationship with developmental regression, language and communication, ASD severity, challenging behavior, comorbid psychopathology, sleep problems, and sensory issues. The review found that GIS were common and that there was contradictory evidence concerning their relationship with co-occurring conditions. It also identified evidence of some causal relationships that support the existence of the gut-immune-brain pathways. Future research needs to use large prospective designs and objective and standardized GIS measurements to provide a nuanced understanding of GIS in the context of ASD.

Alteration of Gut Microbiota: New Strategy for Treating Autism Spectrum Disorder

Autism spectrum disorder (ASD) is defined as a complex heterogeneous disorder and characterized by stereotyped behavior and deficits in communication and social interactions. The emerging microbial knowledge has pointed to a potential link between gut microbiota dysbiosis and ASD. Evidence from animal and human studies showed that shifts in composition and activity of the gut microbiota may causally contribute to the etiopathogenesis of core symptoms in the ASD individuals with gastrointestinal tract disturbances and act on microbiota-gut-brain. In this review, we summarized the characterized gut bacterial composition of ASD and the involvement of gut microbiota and their metabolites in the onset and progression of ASD; the possible underlying mechanisms are also highlighted. Given this correlation, we also provide an overview of the microbial-based therapeutic interventions such as probiotics, antibiotics, fecal microbiota transplantation therapy, and dietary interventions and address their potential benefits on behavioral symptoms of ASD. The precise contribution of altering gut microbiome to treating core symptoms in the ASD needs to be further clarified. It seemed to open up promising avenues to develop microbial-based therapies in ASD.

Gastrointestinal manifestations and their relation to faecal calprotectin in children with autism

Introduction

A common comorbidity in autism spectrum disorder (ASD) children is gastrointestinal problems, and a possible link between active gastrointestinal inflammation and autism has been suggested. Faecal calprotectin (FC) is a non-invasive marker for of gastrointestinal inflammation.

Aim

To study the level of FC as a marker of bowel inflammation in children with ASD and its possible relation to gastrointestinal manifestations.

Material and methods

Calprotectin levels were assessed in stool samples of 40 ASD children. Autism severity was assessed by the Childhood Autism Rating Scale (CARS). Severity of gastrointestinal symptoms was assessed using a modified version of the 6-Item Gastrointestinal Severity Index (6-GSI) questionnaire. A control group of 40 healthy children matched for age and sex with the cases was also included to compare their levels of FC.

Results

Gastrointestinal symptoms were present in 82.5% of children with autism; the most reported offensive stool odour (70%) and the least diarrhoea (17.5%), and a high 6-GSI score was observed in 35% of ASD children. FC levels were elevated in 35% of the cases and in 25% of the control group. The mean levels of FC of cases were significantly elevated compared to levels of controls. FC levels positively correlated with severity of gastrointestinal symptoms (6-GSI) in autistic patients. There was positive correlation between CARS and 6-GSI.

Conclusions

Gastrointestinal manifestations are a common comorbidity in autistic patients. ASD patients have significantly higher FC levels than healthy controls. FC levels are strongly correlated with the severity of gastrointestinal manifestations in ASD children. So, gastrointestinal manifestations among autistic patients could be caused by gastrointestinal inflammation.

Age of Autism Spectrum Disorder Diagnosis and Comorbidity in Children and Adolescents with Autism Spectrum Disorder

AIM

Research is required to study the relationship between age of autism spectrum disorder (ASD) diagnosis and the presence of comorbidities.

METHOD

The Gastrointestinal Symptom Inventory, Autism Spectrum Disorder-Comorbid for Children, Behavior Problem Inventory-Short Form and Social Communication Questionnaire were completed by parents of 129 children and adolescents with a diagnosis of ASD.

RESULTS

Results revealed significant relationships between the age of ASD diagnosis, the presence of comorbidities and intellectual disability. Significant correlations were found between the age of ASD diagnosis and self-injurious and stereotyped behavior. Comorbid psychopathology significantly predicted the presence of GI symptoms. In addition, the relationship between comorbid psychopathology and challenging behavior in this study was reported as bi-directional as both comorbidities predicted one another in the sample.

CONCLUSION

Future research needs to consider the role of comorbidities in relation to ASD diagnosis.

Gut mobilization improves behavioral symptoms and modulates urinary p-cresol in chronically constipated autistic children: A prospective study

Chronic constipation is common among children with ASD and is associated with more severe hyperactivity, anxiety, irritability, and repetitive behaviors. Young autistic children with chronic constipation display higher urinary, and foecal concentrations of p-cresol, an aromatic compound produced by gut bacteria, known to negatively affect brain function. Acute p-cresol administration to BTBR mice enhances anxiety, hyperactivity and stereotypic behaviors, while blunting social interaction. This study was undertaken to prospectively assess the behavioral effects of gut mobilization in young autistic children with chronic constipation, and to verify their possible correlation with urinary p-cresol. To this aim, 21 chronically constipated autistic children 2-8 years old were evaluated before (T0), 1 month (T1), and 6 months (T2) after intestinal mobilization, recording Bristol stool scale scores, urinary p-cresol concentrations, and behavioral scores for social interaction deficits, stereotypic behaviors, anxiety, and hyperactivity. Gut mobilization yielded a progressive and highly significant decrease in all behavioral symptoms over the 6-month study period. Urinary p-cresol levels displayed variable trends not significantly correlated with changes in behavioral parameters, mainly increasing at T1 and decreasing at T2. These results support gut mobilization as a simple strategy to ameliorate ASD symptoms, as well as comorbid anxiety and hyperactivity, in chronically constipated children. Variation in p-cresol absorption seemingly provides limited contributions, if any, to these behavioral changes. Further research will be needed to address the relative role of reduced abdominal discomfort following mobilization, as compared to specific modifications in microbiome composition and in gut bacteria-derived neuroactive compounds.

The Emerging Role of the Gut-Brain-Microbiota Axis in Neurodevelopmental Disorders

Autism spectrum disorder (ASD; autism) is a prevalent neurodevelopmental disorder associated with changes in gut-brain axis communication. Gastrointestinal (GI) symptoms are experienced by a large proportion of individuals diagnosed with autism. Several mutations associated with autism modify cellular communication via neuronal synapses. It has been suggested that modifications to the enteric nervous system, an intrinsic nervous system of the GI tract, could contribute to GI dysfunction. Changes in gut motility, permeability, and the mucosal barrier as well as shifts in the large population of microbes inhabiting the GI tract could contribute to GI symptoms. Preclinical research has demonstrated that mice expressing the well-studied R451C missense mutation in Nlgn3 gene, which encodes cell adhesion protein neuroligin-3 at neuronal synapses, exhibit GI dysfunction. Specifically, NL3^R451C mice show altered colonic motility and faster small intestinal transit. As well as dysmotility, macrophages located within the gut-associated lymphoid tissue of the NL3^R451C mouse caecum show altered morphology, suggesting that neuro-inflammation pathways are modified in this model. Interestingly, NL3^R451C mice maintained in a shared environment demonstrate fecal microbial dysbiosis indicating a role for the nervous system in regulating gut microbial populations. To better understand host-microbe interactions, further clarification and comparison of clinical and animal model profiles of dysbiosis should be obtained, which in turn will provide better insights into the efforts taken to design personalized microbial therapies. In addition to changes in neurophysiological measures, the mucosal component of the GI barrier may contribute to GI dysfunction more broadly in individuals diagnosed with a wide range of neurological disorders. As the study of GI dysfunction advances to encompass multiple components of the gut-brain-microbiota axis, findings will help understand future directions such as microbiome engineering and optimisation of the mucosal barrier for health.