Nutritional and metabolic status of children with autism vs. neurotypical children, and the association with autism severity

Mapping the structure of biomarkers in autism spectrum disorder: a review of the most influential studies

Background

Autism spectrum disorder is a distinctive developmental condition which is caused by an interaction between genetic vulnerability and environmental factors. Biomarkers play a crucial role in understanding disease characteristics for diagnosis, prognosis, and treatment. This study employs bibliometric analysis to identify and review the 100 top-cited articles' characteristics, current research hotspots and future directions of autism biomarkers.

Methods

A comprehensive search of autism biomarkers studies was retrieved from the Web of Science Core Collection database with a combined keyword search strategy. A comprehensive analysis of the top 100 articles was conducted with CiteSpace, VOSviewer, and Excel, including citations, countries, authors, and keywords.

Results

The top 100 cited studies were published between 1988 and 2021, with the United States led in productivity. Core biomarkers such as genetics, children, oxidative stress, and mitochondrial dysfunction are well-established. Potential trends for future research may include brain studies, metabolomics, and associations with other psychiatric disorders.

Conclusion

This pioneering bibliometric analysis provides a comprehensive compilation of the 100 most-cited studies on autism, which not only offers a valuable resource for doctors, and researchers but shedding insights into current shortcomings and future endeavors. Future research should prioritize the application of emerging technologies for biomarkers, longitudinal study of biomarkers, and specificity of autism biomarkers to advance the precision of ASD diagnosis and treatment.

Nutritional management and autism spectrum disorder: A systematic review

BACKGROUND

Autism spectrum disorder (ASD) presents unique challenges related to feeding and nutritional management. Children with ASD often experience feeding difficulties, including food selectivity, refusal, and gastrointestinal issues. Various interventions have been explored to address these challenges, including dietary modifications, vitamin supplementation, feeding therapy, and behavioral interventions.

AIM

To provide a comprehensive overview of the current evidence on nutritional management in ASD. We examine the effectiveness of dietary interventions, vitamin supplements, feeding therapy, behavioral interventions, and mealtime practices in addressing the feeding challenges and nutritional needs of children with ASD.

METHODS

We systematically searched relevant literature up to June 2024, using databases such as PubMed, PsycINFO, and Scopus. Studies were included if they investigated dietary interventions, nutritional supplements, or behavioral strategies to improve feeding behaviors in children with ASD. We assessed the quality of the studies and synthesized findings on the impact of various interventions on feeding difficulties and nutritional outcomes. Data extraction focused on intervention types, study designs, participant characteristics, outcomes measured, and intervention effectiveness.

RESULTS

The review identified 316 studies that met the inclusion criteria. The evidence indicates that while dietary interventions and nutritional supplements may offer benefits in managing specific symptoms or deficiencies, the effectiveness of these approaches varies. Feeding therapy and behavioral interventions, including gradual exposure and positive reinforcement, promise to improve food acceptance and mealtime behaviors. The findings also highlight the importance of creating supportive mealtime environments tailored to the sensory and behavioral needs of children with ASD.

CONCLUSION

Nutritional management for children with ASD requires a multifaceted approach that includes dietary modifications, supplementation, feeding therapy, and behavioral strategies. The review underscores the need for personalized interventions and further research to refine treatment protocols and improve outcomes. Collaborative efforts among healthcare providers, educators, and families are essential to optimize this population's nutritional health and feeding practices. Enhancing our understanding of intervention sustainability and long-term outcomes is essential for optimizing care and improving the quality of life for children with ASD and their families.

Sulfate: a neglected (but potentially highly relevant) anion

Sulfate is an important anion as sulfonation is essential in modulation of several compounds, such as exogens, polysaccharide chains of proteoglycans, cholesterol or cholesterol derivatives and tyrosine residues of several proteins. Sulfonation requires the presence of both the sulfate donor 3'-phosphoadenosine-5'-phosphosulfate (PAPS) and a sulfotransferase. Genetic disorders affecting sulfonation, associated with skeletal abnormalities, impaired neurological development and endocrinopathies, demonstrate the importance of sulfate. Yet sulfate is not measured in clinical practice. This review addresses sulfate metabolism and consequences of sulfonation defects, how to measure sulfate and why we should measure sulfate more often.

High-dose Vitamin-B6 reduces sensory over-responsivity

BACKGROUND

Sensory reactivity differences are experienced by between 5% and 15% of the population, often taking the form of sensory over-responsivity (SOR), in which sensory stimuli are experienced as unusually intense and everyday function is affected. A potential mechanism underlying over-responsivity is an imbalance between neural excitation and inhibition in which inhibitory influences are relatively weakened. Therefore, interventions that boost neural inhibition or reduce neural excitation may reduce SOR; Vitamin-B6 is the coenzyme for the conversion of excitatory glutamate to inhibitory gamma-aminobutyric acid (GABA), and in animal models, it both increases the concentration of GABA and reduces glutamate.

AIMS

To discover whether taking a high dose of Vitamin-B6 reduces SOR and other aspects of sensory reactivity.

METHODS

We recruited 300 adults (249 females) from the general population who completed the Sensory Processing 3-Dimensions Scale (SP-3D) first at baseline, and again following randomisation to either 1 month's supplementation with 100 mg Vitamin-B6, or one of two control conditions (1000 µg Vitamin-B12 or placebo). To focus on individuals who experience SOR, we analysed the effects of supplementation only on individuals with high baseline SOR scores (above the 87th percentile).

RESULTS

In individuals with SOR at baseline, Vitamin-B6 selectively reduced SOR compared to both placebo and Vitamin-B12. We also found that Vitamin-B6 selectively reduced postural disorder in individuals with high scores on this subscale at baseline, but there were no effects on the four remaining SP-3D subscales.

CONCLUSIONS

Clinical trials and mechanistic studies should now be conducted in autism, attention deficit hyperactivity disorder and other groups with SOR.

Differential One-Carbon Metabolites among Children with Autism Spectrum Disorder: A Case-Control Study

BACKGROUND

Driven by the complex multifactorial etiopathogenesis of autism spectrum disorder (ASD), a growing interest surrounds the disturbance in folate-dependent one-carbon metabolism (OCM) in the pathology of ASD, whereas the evidence remained inconclusive.

OBJECTIVES

The study aims to investigate the association of OCM metabolism and ASD and characterize differential OCM metabolites among children with ASD.

METHODS

Plasma OCM metabolites were investigated in 59 children with ASD and 40 neurotypical children using ultra-performance liquid chromatography tandem mass spectrometry technology. Differences (significance level < 0.001) were tested in each OCM metabolite between cases and controls. Multivariable models were also performed after adjusting for covariates.

RESULTS

Ten out of 22 examined OCM metabolites were significantly different in children with ASD, compared with neurotypical controls. Specifically, S-adenosylmethionine (SAM), oxidized glutathione (GSSG), and glutathione (GSH) levels were increased, whereas S-adenosylhomocysteine (SAH), choline, glycine, L-serine, cystathionine, L-cysteine, and taurine levels were significantly decreased. Children with ASD showed significantly higher SAM/SAH ratio (3.87 ± 0.93 compared with 2.00 ± 0.76, P = 0.0001) and lower GSH/GSSG ratio [0.58 (0.46, 0.81) compared with 1.71 (0.93, 2.99)] compared with the neurotypical controls. Potential interactive effects between SAM/SAH ratio, taurine, L-serine, and gastrointestinal syndromes were further observed.

CONCLUSIONS

OCM disturbance was observed among children with ASD, particularly in methionine methylation and trans-sulfuration pathways. The findings add valuable insights into the mechanisms underlying ASD and the potential of ameliorating OCM as a promising therapeutic of ASD, which warrant further validation.

P2X7 expression patterns in the developing Fmr1-knockout mouse hippocampus

Fragile-X Syndrome (FXS) is the leading monogenetic cause of intellectual disability among children but remains without a cure. Using the Fmr1 KO mouse model of FXS, much work has been done to understand FXS hippocampus dysfunction. Purinergic signaling, where ATP and its metabolites are used as signaling molecules, participates in hippocampus development, but it is unknown if purinergic signaling is affected in the developing Fmr1 KO hippocampus. In our study, we characterized the purinergic receptor P2X7. We first found that P2X7 was reduced in Fmr1 KO whole hippocampus tissue at P14 and P21, corresponding to the periods of neurite outgrowth and synaptic refinement in the hippocampus. We then evaluated the cell-specific expression of P2X7 with immunofluorescence and found differences between WT and Fmr1 KO mice in P2X7 colocalization with hippocampal microglia and neurons. P2X7 colocalized more with microglia at P14 and P21, but there was a sex-specific reduction in P2X7 colocalization with neurons. In contrast, male mice at P14 and P21 showed reduced neuronal P2X7 colocalization compared to females, but only females showed reduced absolute neuronal P2X7 expression across the dorsal hippocampal formation. Together, our results suggest that P2X7 expression is altered during Fmr1-KO hippocampal development, potentially influencing several developmental processes in the Fmr1-KO hippocampus formation.

Exploring Nutritional Status and Metabolic Imbalances in Children with FASD: A Cross-Sectional Study

BACKGROUND/OBJECTIVES

Malnutrition is a significant concern in paediatric populations, particularly among children with neurodevelopmental disorders such as foetal alcohol spectrum disorder (FASD). This study aimed to examine macronutrient and micronutrient imbalances and assess the nutritional status of a group of patients with FASD.

METHODS

This study involved an analysis of the serum levels of key nutrients in a group of children diagnosed with FASD. Macronutrients and micronutrients were measured to identify any imbalances, including vitamin D, B12, E, A, albumin, and serum protein, among others.

RESULTS

The study found a high prevalence of vitamin D deficiency among the patients. Additionally, elevated serum concentrations of micronutrients such as vitamin B12, E, and A were observed in 8%, 7%, and 19% of patients, respectively. Macronutrient imbalances were noted, including high levels of albumin and serum protein, indicating a possible metabolic disturbance. Unexpectedly, high rates of hypercholesterolemia were observed, raising concerns about an increased risk of metabolic syndrome in this population.

CONCLUSIONS

These findings suggest that the principal issue among patients with FASD is an altered metabolism rather than nutritional deficiencies. Potential causes of these abnormalities could include oxidative stress and changes in body composition. The results underline the need for further research to better understand the unique nutritional challenges in children with FASD and to guide the development of targeted therapeutic strategies.

Nutrient intake and food selectivity in children with Tourette syndrome

Objectives: Children with Tourette syndrome (TS) have been shown to exhibit high levels of food selectivity; however, its association with nutritional status has yet to be explored. The current study explored macro and micronutrient intake and food selectivity among children with and without TS, using 24-hour dietary recall and the Child Eating Behaviour Questionnaire.Method: Parents of 43 children diagnosed with TS and 38 age-matched children without a clinical diagnosis completed an online 24-hour food diary.Results: Fifty-eight per cent of children with TS were identified as falling outside of the healthy BMI range (underweight = 24.2%; overweight = 27.3%; obese = 6.1%). Children with TS also consumed fewer portions of fruit and vegetables along with meeting the daily reference nutrient intake guidelines significantly less often for vitamins B3, B6 and C, selenium and phosphorus compared to children without TS.Conclusions: Understanding the nutritional risk of children with TS relative to other children is important to clinicians and health care professionals who oversee nutritional inspection in primary care, and caregivers who are worried about the impact of limited or restricted diets.

Interaction and association between multiple vitamins and social adaptability and severity of autism: A large-scale retrospective study from China

Since children with autism spectrum disorder (ASD) often exhibit selective eating behaviors, it is generally believed that they may have abnormal nutrient structure, leading to aberrant concentrations of some serum vitamins. However, previous studies on serum vitamins in individuals with ASD are mixed. Additionally, the interaction and association between multiple serum vitamin and ASD-related symptoms remain unclear. This study utilized a cross-sectional survey with a large sample size (n = 1235) from China to clarify previous mixed findings, and examine the interaction and association between multiple serum vitamins (including folic acid [FA], vitamin A [VA], vitamin E [VE], vitamin B12 [VB12], and vitamin D [VD]) and social adaptability and symptom severity in children with ASD. Findings found that symptom severity was negatively associated with concentrations of serum VA, VE, VB12, and VD; while, social adaptability was significantly associated with the natural log-transformed concentrations of FA and VB12. Finding also revealed the interaction of VA and VE on the association between both vitamins and severity of ASD symptoms, as well as the interaction of VB12 and FA on the association between both vitamins and social adaptability. In particular, the combination of low concentration of VA and high concentration of VE is associated with the lowest risk of being "severely autistic"; while, the combination of low concentration of FA and high concentration of VB12 is associated with the lowest risk of being "poor social adaptability". This study offers the evidence for the requirement of considering multiple vitamins comprehensively, as well as valuable references for revealing the association between vitamin disparities and food selectivity in children with ASD.

Blood and hair copper levels in childhood autism spectrum disorder: a meta-analysis based on case-control studies

OBJECTIVES

The association between copper levels and autism spectrum disorder (ASD) has been a controversial topic. This study investigated relationship between copper levels and ASD.

CONTENT

The following databases are searched until April 2022: PubMed, EMBASE and Web of Science. Combined effect size standardized mean differences (SMD) and 95% confidence intervals (95% CI) were calculated with Stata 12.0. In this meta-analysis, 29 case-control studies were included, which included 2,504 children with ASD and 2,419 healthy controls. The copper levels in hair (SMD: -1.16, 95% CI: -1.73 to -0.58) was significantly lower in ASD children than healthy controls. The copper levels in blood (SMD: 0.10, 95% CI: -0.12 to 0.32) not significantly compare ASD with controls.

SUMMARY AND OUTLOOK

Copper may be associated with the development of ASD in children.

Dysregulated Purinergic Signalling in Fragile X Syndrome Cortical Astrocytes

The symptoms of fragile X syndrome (FXS), caused by a single gene mutation to Fmr1, have been increasingly linked to disordered astrocyte signalling within the cerebral cortex. We have recently demonstrated that the purinergic signalling pathway, which utilizes nucleoside triphosphates and their metabolites to facilitate bidirectional glial and glial-neuronal interactions, is upregulated in cortical astrocytes derived from the Fmr1 knockout (KO) mouse model of FXS. Heightened Fmr1 KO P2Y purinergic receptor levels were correlated with prolonged intracellular calcium release, elevated synaptogenic protein secretion, and hyperactivity of developing circuits. However, due to the relative lack of sensitive and reproducible quantification methods available for measuring purines and pyrimidines, determining the abundance of these factors in Fmr1 KO astrocytes was limited. We therefore developed a hydrophilic interaction liquid chromatography protocol coupled with mass spectrometry to compare the abundance of intracellular and extracellular purinergic molecules between wildtype and Fmr1 KO mouse astrocytes. Significant differences in the concentrations of UDP, ATP, AMP, and adenosine intracellular stores were found within Fmr1 KO astrocytes relative to WT. The extracellular level of adenosine was also significantly elevated in Fmr1 KO astrocyte-conditioned media in comparison to media collected from WT astrocytes. Glycosylation of the astrocyte membrane-bound CD39 ectonucleotidase, which facilitates ligand breakdown following synaptic release, was also elevated in Fmr1 KO astrocyte cultures. Together, these differences demonstrated further dysregulation of the purinergic signalling system within Fmr1 KO cortical astrocytes, potentially leading to significant alterations in FXS purinergic receptor activation and cellular pathology.

Complementary and Alternative Medicine for Autism - A Systematic Review

Complementary and Alternative Medicine (CAM) is a therapeutic option currently used by autistic people with continued interest and uptake. There remains limited evidence regarding the efficacy of CAM use in autism. The aim of this systematic review is to comprehensively review published clinical trials to explore the efficacy of CAM in autism. A systematic literature review of available research published from June 2013 to March 2023 was conducted. Our literature search identified 1826 eligible citations, and duplications removed (n = 694) with 102 articles eligible for title/abstract screening. After full text review, 39 studies were included. The results of this systematic review identified that for autistic people, vitamin and mineral supplements may only be of benefit if there is a deficiency. The results also found that the main interventions used were dietary interventions and nutraceuticals, including targeted supplements, vitamins and minerals, omega 3 s and prebiotics, probiotics and digestive enzymes. The evidence does not support some of the most frequently utilised dietary interventions, such as a Gluten Free Casein Free (GFCF) diet, and the use of targeted nutraceutical supplements may be of benefit, but more conclusive research is still required to direct safe and effective treatment.

Biomarkers of mitochondrial dysfunction in autism spectrum disorder: A systematic review and meta-analysis

Autism spectrum disorder (ASD) is a neurodevelopmental disorder affecting 1 in 36 children and is associated with physiological abnormalities, most notably mitochondrial dysfunction, at least in a subset of individuals. This systematic review and meta-analysis discovered 204 relevant articles which evaluated biomarkers of mitochondrial dysfunction in ASD individuals. Significant elevations (all p < 0.01) in the prevalence of lactate (17%), pyruvate (41%), alanine (15%) and creatine kinase (9%) were found in ASD. Individuals with ASD had significant differences (all p < 0.01) with moderate to large effect sizes (Cohen's d' ≥ 0.6) compared to controls in mean pyruvate, lactate-to-pyruvate ratio, ATP, and creatine kinase. Some studies found abnormal TCA cycle metabolites associated with ASD. Thirteen controlled studies reported mitochondrial DNA (mtDNA) deletions or variations in the ASD group in blood, peripheral blood mononuclear cells, lymphocytes, leucocytes, granulocytes, and brain. Meta-analyses discovered significant differences (p < 0.01) in copy number of mtDNA overall and in ND1, ND4 and CytB genes. Four studies linked specific mtDNA haplogroups to ASD. A series of studies found a subgroup of ASD with elevated mitochondrial respiration which was associated with increased sensitivity of the mitochondria to physiological stressors and neurodevelopmental regression. Lactate, pyruvate, lactate-to-pyruvate ratio, carnitine, and acyl-carnitines were associated with clinical features such as delays in language, social interaction, cognition, motor skills, and with repetitive behaviors and gastrointestinal symptoms, although not all studies found an association. Lactate, carnitine, acyl-carnitines, ATP, CoQ10, as well as mtDNA variants, heteroplasmy, haplogroups and copy number were associated with ASD severity. Variability was found across biomarker studies primarily due to differences in collection and processing techniques as well as the intrinsic heterogeneity of the ASD population. Several studies reported alterations in mitochondrial metabolism in mothers of children with ASD and in neonates who develop ASD. Treatments targeting mitochondria, particularly carnitine and ubiquinol, appear beneficial in ASD. The link between mitochondrial dysfunction in ASD and common physiological abnormalities in individuals with ASD including gastrointestinal disorders, oxidative stress, and immune dysfunction is outlined. Several subtypes of mitochondrial dysfunction in ASD are discussed, including one related to neurodevelopmental regression, another related to alterations in microbiome metabolites, and another related to elevations in acyl-carnitines. Mechanisms linking abnormal mitochondrial function with alterations in prenatal brain development and postnatal brain function are outlined. Given the multisystem complexity of some individuals with ASD, this review presents evidence for the mitochondria being central to ASD by contributing to abnormalities in brain development, cognition, and comorbidities such as immune and gastrointestinal dysfunction as well as neurodevelopmental regression. A diagnostic approach to identify mitochondrial dysfunction in ASD is outlined. From this evidence, it is clear that many individuals with ASD have alterations in mitochondrial function which may need to be addressed in order to achieve optimal clinical outcomes. The fact that alterations in mitochondrial metabolism may be found during pregnancy and early in the life of individuals who eventually develop ASD provides promise for early life predictive biomarkers of ASD. Further studies may improve the understanding of the role of the mitochondria in ASD by better defining subgroups and understanding the molecular mechanisms driving some of the unique changes found in mitochondrial function in those with ASD.

Metabolomic changes in children with autism

BACKGROUND

Autism spectrum disorder (ASD) is a neurodevelopmental condition characterized by deficits in social communication and repetitive behaviors. Metabolomic profiling has emerged as a valuable tool for understanding the underlying metabolic dysregulations associated with ASD.

AIM

To comprehensively explore metabolomic changes in children with ASD, integrating findings from various research articles, reviews, systematic reviews, meta-analyses, case reports, editorials, and a book chapter.

METHODS

A systematic search was conducted in electronic databases, including PubMed, PubMed Central, Cochrane Library, Embase, Web of Science, CINAHL, Scopus, LISA, and NLM catalog up until January 2024. Inclusion criteria encompassed research articles (83), review articles (145), meta-analyses (6), systematic reviews (6), case reports (2), editorials (2), and a book chapter (1) related to metabolomic changes in children with ASD. Exclusion criteria were applied to ensure the relevance and quality of included studies.

RESULTS

The systematic review identified specific metabolites and metabolic pathways showing consistent differences in children with ASD compared to typically developing individuals. These metabolic biomarkers may serve as objective measures to support clinical assessments, improve diagnostic accuracy, and inform personalized treatment approaches. Metabolomic profiling also offers insights into the metabolic alterations associated with comorbid conditions commonly observed in individuals with ASD.

CONCLUSION

Integration of metabolomic changes in children with ASD holds promise for enhancing diagnostic accuracy, guiding personalized treatment approaches, monitoring treatment response, and improving outcomes. Further research is needed to validate findings, establish standardized protocols, and overcome technical challenges in metabolomic analysis. By advancing our understanding of metabolic dysregulations in ASD, clinicians can improve the lives of affected individuals and their families.

Seeing beyond words: Visualizing autism spectrum disorder biomarker insights

Objective

This study employs bibliometric and visual analysis to elucidate global research trends in Autism Spectrum Disorder (ASD) biomarkers, identify critical research focal points, and discuss the potential integration of diverse biomarker modalities for precise ASD assessment.

Methods

A comprehensive bibliometric analysis was conducted using data from the Web of Science Core Collection database until December 31, 2022. Visualization tools, including R, VOSviewer, CiteSpace, and gCLUTO, were utilized to examine collaborative networks, co-citation patterns, and keyword associations among countries, institutions, authors, journals, documents, and keywords.

Results

ASD biomarker research emerged in 2004, accumulating a corpus of 4348 documents by December 31, 2022. The United States, with 1574 publications and an H-index of 213, emerged as the most prolific and influential country. The University of California, Davis, contributed significantly with 346 publications and an H-index of 69, making it the leading institution. Concerning journals, the Journal of Autism and Developmental Disorders, Autism Research, and PLOS ONE were the top three publishers of ASD biomarker-related articles among a total of 1140 academic journals. Co-citation and keyword analyses revealed research hotspots in genetics, imaging, oxidative stress, neuroinflammation, gut microbiota, and eye tracking. Emerging topics included "DNA methylation," "eye tracking," "metabolomics," and "resting-state fMRI."

Conclusion

The field of ASD biomarker research is dynamically evolving. Future endeavors should prioritize individual stratification, methodological standardization, the harmonious integration of biomarker modalities, and longitudinal studies to advance the precision of ASD diagnosis and treatment.

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.

Plasma Amino Acid Profile in Children with Autism Spectrum Disorder in Southern China: Analysis of 110 Cases

To retrospectively explore the characteristics of plasma amino acids (PAAs) in children with autism spectrum disorder and their clinical association via case-control study. A total of 110 autistic and 55 healthy children were recruited from 2014 to 2018. The clinical phenotypes included severity of autism, cognition, adaptability, and regression. Compared with the control group, autistic children had significantly elevated glutamate, γ-Amino-n-butyric acid, glutamine, sarcosine, δ-aminolevulinic acid, glycine and citrulline. In contrast, their plasma level of ethanolamine, phenylalanine, tryptophan, homocysteine, pyroglutamic acid, hydroxyproline, ornithine, histidine, lysine, and glutathione were significantly lower. Elevated neuroactive amino acids (glutamate) and decreased essential amino acids were mostly distinct characteristics of PAAs of autistic children. Increased level of tryptophan might be associated with severity of autism.

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.

Untargeted urine metabolomics and machine learning provide potential metabolic signatures in children with autism spectrum disorder

Background

Complementary to traditional biostatistics, the integration of untargeted urine metabolomic profiling with Machine Learning (ML) has the potential to unveil metabolic profiles crucial for understanding diseases. However, the application of this approach in autism remains underexplored. Our objective was to delve into the metabolic profiles of autism utilizing a comprehensive untargeted metabolomics platform coupled with ML.

Methods

Untargeted metabolomics quantification (UHPLC/Q-TOF-MS) was performed for urine analysis. Feature selection was conducted using Lasso regression, and logistic regression, support vector machine, random forest, and extreme gradient boosting were utilized for significance stratification. Pathway enrichment analysis was performed to identify metabolic pathways associated with autism.

Results

A total of 52 autistic children and 40 typically developing children were enrolled. Lasso regression identified ninety-two urinary metabolites that significantly differed between the two groups. Distinct metabolites, such as prostaglandin E2, phosphonic acid, lysine, threonine, and phenylalanine, were revealed to be associated with autism through the application of four different ML methods (p<0.05). The alterations observed in the phosphatidylinositol and inositol phosphate metabolism pathways were linked to the pathophysiology of autism (p<0.05).

Conclusion

Significant urinary metabolites, including prostaglandin E2, phosphonic acid, lysine, threonine, and phenylalanine, exhibit associations with autism. Additionally, the involvement of the phosphatidylinositol and inositol phosphate pathways suggests their potential role in the pathophysiology of autism.

The role and impact of abnormal vitamin levels in autism spectrum disorders

The prevalence of autism spectrum disorder (ASD), a neurodevelopmental disorder with a predominance of social behavioral disorders, has increased dramatically in various countries in recent decades. The interplay between genetic and environmental factors is believed to underlie ASD pathogenesis. Recent analyses have shown that abnormal vitamin levels in early life are associated with an increased risk of autism. As essential substances for growth and development, vitamins have been shown to have significant benefits for the nervous and immune systems. However, it is unknown whether certain vitamin types influence the emergence or manifestation of ASD symptoms. Several studies have focused on vitamin levels in children with autism, and neurotypical children have provided different insights into the types of vitamins and their intake. Here, we review the mechanisms and significance of several vitamins (A, B, C, D, E, and K) that are closely associated with the development of ASD in order to prevent, mitigate, and treat ASD. Efforts have been made to discover and develop new indicators for nutritional assessment of children with ASD to play a greater role in the early detection of ASD and therapeutic remission after diagnosis.

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.

Autism Spectrum Disorder and Eating Problems: The Imbalance of Gut Microbiota and the Gut-Brain Axis Hypothesis

This review explores the complexities of autism spectrum disorder (ASD), primarily focusing on the significant eating challenges faced by children and adolescents with this neurodevelopmental condition. It is common for individuals with ASD to exhibit heightened sensitivity to various sensory aspects of food such as taste, texture, smell, and visual appeal, leading to restricted and less diverse diets. These dietary limitations are believed to contribute to an imbalance in the gut microbiota. This review elaborates on how these eating problems, coupled with the distinctive characteristics of ASD, might be influenced by and, in turn, influence the gut-brain axis, a bidirectional communication system between the gastrointestinal tract and the brain. This discussion aims to shed light on the multifaceted interactions and potential implications of diet, gut health, and neurological development and function in children and adolescents with ASD.

The Role of Short-Chain Fatty Acids and Altered Microbiota Composition in Autism Spectrum Disorder: A Comprehensive Literature Review

Autism spectrum disorder (ASD) is a complex neurodevelopmental condition characterized by deficits in communication and social interactions, restrictive and repetitive behavior, and a wide range of cognitive impediments. The prevalence of ASD tripled in the last 20 years and now affects 1 in 44 children. Although ASD's etiology is not yet elucidated, a growing body of evidence shows that it stems from a complex interplay of genetic and environmental factors. In recent years, there has been increased focus on the role of gut microbiota and their metabolites, as studies show that ASD patients show a significant shift in their gut composition, characterized by an increase in specific bacteria and elevated levels of short-chain fatty acids (SCFAs), especially propionic acid (PPA). This review aims to provide an overview of the role of microbiota and SCFAs in the human body, as well as possible implications of microbiota shift. Also, it highlights current studies aiming to compare the composition of the gut microbiome of ASD-afflicted patients with neurotypical control. Finally, it highlights studies with rodents where ASD-like symptoms or molecular hallmarks of ASD are evoked, via the grafting of microbes obtained from ASD subjects or direct exposure to PPA.

The tryptophan catabolite or kynurenine pathway in autism spectrum disorder; a systematic review and meta-analysis

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by impaired social communication and interaction, as well as rigid and unchanging interests and behaviors. Several studies have reported that activated immune-inflammatory and nitro-oxidative pathways are accompanied by depletion of plasma tryptophan (TRP), increased competing amino acid (CAAs) levels, and activation of the TRP catabolite (TRYCAT) pathway. This study aims to systematically review and meta-analyze data on peripheral TRP, CAAs, TRYCAT pathway activity, and individual TRYCATs, including kynurenine (KYN) and kynurenic acid (KA) levels, in the blood and urine of ASD patients. After extensively searching PubMed, Google Scholar, and SciFinder, a total of 25 full-text papers were included in the analysis, with a total of 6653 participants (3557 people with ASD and 3096 healthy controls). Our results indicate that blood TRP and the TRP/CAAs ratio were not significantly different between ASD patients and controls (standardized mean difference, SMD = -0.227, 95% confidence interval, CI: -0.540; 0.085, and SMD = 0.158, 95% CI: -0.042; 0.359), respectively. The KYN/TRP ratio showed no significant difference between ASD and controls (SMD = 0.001, 95% CI: -0.169; 0.171). Blood KYN and KA levels were not significantly changed in ASD. Moreover, there were no significant differences in urine TRP, KYN, and KA levels between ASD and controls. We could not establish increases in neurotoxic TRYCATs in ASD. In conclusion, this study demonstrates no abnormalities in peripheral blood TRP metabolism, indoleamine 2,3-dioxygenase enzyme (IDO) activity, or TRYCAT production in ASD. Reduced TRP availability and elevated neurotoxic TRYCAT levels are not substantial contributors to ASD's pathophysiology.

Expression of miRNAs in Pre-Schoolers with Autism Spectrum Disorders Compared with Typically Developing Peers and Its Effects after Probiotic Supplementation

Alteration of the microbiota-gut-brain axis has been recently recognized as a possible contributor to the physiopathology of autism spectrum disorder (ASD). In this context, microRNA (miRNAs) dysfunction, implicated both in several neuropathological conditions including ASD and in different gastrointestinal disorders (GIDs), could represent an important modulating factor. In this contextual framework, we studied the transcriptional profile of specific circulating miRNAs associated with both ASD (miR-197-5p, miR-424-5p, miR-500a-5p, miR-664a-5p) and GID (miR-21-5p, miR-320a-5p, miR-31-5p, miR-223-5p) in a group of pre-schoolers with ASD and in typically developing (TD) peers. In the ASD group, we also assessed the same miRNAs after a 6-month supplementation with probiotics and their correlation with plasma levels of zonulin and lactoferrin. At baseline, the expression of miRNAs involved in ASD were significantly reduced in ASD pre-schoolers vs. TD controls. Regarding the miRNAs involved in GID, the expression levels of miR-320-5p, miR-31-5p, and miR-223-5p were significantly higher in ASD than in TD subjects, whereas miR-21-5p showed significantly reduced expression in the ASD group vs. TD group. Supplementation with probiotics did not significantly change the expression of miRNAs in the ASD population. We found a significative negative correlation between zonulin and miR-197-5p and miR-21-5p at baseline, as well as between lactoferrin and miR-223-5p after 6 months of probiotic supplementation. Our study confirms the presence of an altered profile of the miRNAs investigated in ASD versus TD peers that was not modified by supplementation with probiotics.

Using urine FTIR spectra to screen autism spectrum disorder

Autism spectrum disorder (ASD) is a heterogeneous neurodevelopmental disorder caused by multiple factors, lacking clear biomarkers. Diagnosing ASD still relies on behavioural and developmental signs and usually requires lengthy observation periods, all of which are demanding for both clinicians and parents. Although many studies have revealed valuable knowledge in this field, no clearly defined, practical, and widely acceptable diagnostic tool exists. In this study, 26 children with ASD (ASD+), aged 3-5 years, and 26 sex and age-matched controls are studied to investigate the diagnostic potential of the Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) spectroscopy. The urine FTIR spectrum results show a downward trend in the 3000-2600/cm region for ASD+ children when compared to the typically developing (TD) children of the same age. The average area of this region is 25% less in ASD+ level 3 children, 29% less in ASD+ level 2 children, and 16% less in ASD+ level 1 children compared to that of the TD children. Principal component analysis was applied to the two groups using the entire spectrum window and five peaks were identified for further analysis. The correlation between the peaks and natural urine components is validated by artificial urine solutions. Less-than-normal levels of uric acid, phosphate groups, and ammonium ([Formula: see text]) can be listed as probable causes. This study shows that ATR-FTIR can serve as a practical and non-invasive method to screen ASD using the high-frequency region of the urine spectrum.

Effects of Walnut and Pumpkin on Selective Neurophenotypes of Autism Spectrum Disorders: A Case Study

Special diets or nutritional supplements are regularly given to treat children with autism spectrum disorder (ASD). The increased consumption of particular foods has been demonstrated in numerous trials to lessen autism-related symptoms and comorbidities. A case study on a boy with moderate autism who significantly improved after three years of following a healthy diet consisting of pumpkin and walnuts was examined in this review in connection to a few different neurophenotypes of ASD. We are able to suggest that a diet high in pumpkin and walnuts was useful in improving the clinical presentation of the ASD case evaluated by reducing oxidative stress, neuroinflammation, glutamate excitotoxicity, mitochondrial dysfunction, and altered gut microbiota, all of which are etiological variables. Using illustrated figures, a full description of the ways by which a diet high in pumpkin and nuts could assist the included case is offered.

Ratings of the Effectiveness of 13 Therapeutic Diets for Autism Spectrum Disorder: Results of a National Survey

This study presents the results of the effectiveness of 13 therapeutic diets for autism spectrum disorder from 818 participants of a national survey, including benefits, adverse effects, and symptom improvements. The average Overall Benefit of diets was 2.36 (0 = no benefit, 4 = great benefit), which was substantially higher than for nutraceuticals (1.59/4.0) and psychiatric/seizure medications (1.39/4.0), p < 0.001. The average Overall Adverse Effects of diets was significantly lower than psychiatric/seizure medications (0.10 vs. 0.93, p < 0.001) and similar to nutraceuticals (0.16). Autism severity decreased slightly over time in participants who used diet vs. increasing slightly in those that did not (p < 0.001). Healthy and Feingold diets were the two top-rated diets by Overall Benefit; the ketogenic diet was the highest for nine symptoms (though had fewer respondents); and the gluten-free/casein-free diet was among the top for overall symptom improvements. Different diets were reported to affect different symptoms, suggesting that an individual's symptoms could be used to guide which diet(s) may be the most effective. The results suggest that therapeutic diets can be safe and effective interventions for improving some ASD-related symptoms with few adverse effects. We recommend therapeutic diets that include healthy foods and exclude problematic foods. Therapeutic diets are inexpensive treatments that we recommend for consideration by most people with ASD.

Fecal microbiota transplantation in a child with severe ASD comorbidities of gastrointestinal dysfunctions-a case report

Autism spectrum disorder (ASD) is a neurodevelopmental disorder defined by social communication impairments and restricted, repetitive behaviors. In addition to behavioral interventions and psychotherapies, and pharmacological interventions, in-depth studies of intestinal microbiota in ASD has obvious abnormalities which may effectively influenced in ASD. Several attempts have been made to indicate that microbiota can reduce the occurrence of ASD effectively. Fecal microbiota transplantation (FMT) is a type of biological therapy that involves the transplant of intestinal microbiota from healthy donors into the patient's gastrointestinal tract to improve the gut microenvironment. In this case report, we describe a case of child ASD treated by FMT. The patient have poor response to long-term behavioral interventions. After five rounds of FMT, clinical core symptoms of ASD and gastrointestinal(GI) symptoms were significantly altered. Moreover, the multiple levels of functional development of child were also significantly ameliorated. We found that FMT changed the composition of the intestinal microbiota as well as the metabolites, intestinal inflammatory manifestations, and these changes were consistent with the patient's symptoms. This report suggests further FMT studies in ASD could be worth pursuing, and more studies are needed to validate the effectiveness of FMT in ASD and its mechanisms.

Topic modeling for multi-omic integration in the human gut microbiome and implications for Autism

While healthy gut microbiomes are critical to human health, pertinent microbial processes remain largely undefined, partially due to differential bias among profiling techniques. By simultaneously integrating multiple profiling methods, multi-omic analysis can define generalizable microbial processes, and is especially useful in understanding complex conditions such as Autism. Challenges with integrating heterogeneous data produced by multiple profiling methods can be overcome using Latent Dirichlet Allocation (LDA), a promising natural language processing technique that identifies topics in heterogeneous documents. In this study, we apply LDA to multi-omic microbial data (16S rRNA amplicon, shotgun metagenomic, shotgun metatranscriptomic, and untargeted metabolomic profiling) from the stool of 81 children with and without Autism. We identify topics, or microbial processes, that summarize complex phenomena occurring within gut microbial communities. We then subset stool samples by topic distribution, and identify metabolites, specifically neurotransmitter precursors and fatty acid derivatives, that differ significantly between children with and without Autism. We identify clusters of topics, deemed "cross-omic topics", which we hypothesize are representative of generalizable microbial processes observable regardless of profiling method. Interpreting topics, we find each represents a particular diet, and we heuristically label each cross-omic topic as: healthy/general function, age-associated function, transcriptional regulation, and opportunistic pathogenesis.

NAD+ Precursors and Intestinal Inflammation: Therapeutic Insights Involving Gut Microbiota

The oxidized form of nicotinamide adenine dinucleotide (NAD+) is a critical metabolite for living cells. NAD+ may act either as a cofactor for many cellular reactions as well as a coenzyme for different NAD+-consuming enzymes involved in the physiological homeostasis of different organs and systems. In mammals, NAD+ is synthesized from either tryptophan or other vitamin B3 intermediates that act as NAD+ precursors. Recent research suggests that NAD+ precursors play a crucial role in maintaining the integrity of the gut barrier. Indeed, its deficiency has been associated with enhanced gut inflammation and leakage, and dysbiosis. Conversely, NAD+-increasing therapies may confer protection against intestinal inflammation in experimental conditions and human patients, with accumulating evidence indicating that such favorable effects could be, at least in part, mediated by concomitant changes in the composition of intestinal microbiota. However, the mechanisms by which NAD+-based treatments affect the microbiota are still poorly understood. In this context, we have focused specifically on the impact of NAD+ deficiency on intestinal inflammation and dysbiosis in animal and human models. We have further explored the relationship between NAD+ and improved host intestinal metabolism and immunity and the composition of microbiota in vivo. Overall, this comprehensive review aims to provide a new perspective on the effect of NAD+-increasing strategies on host intestinal physiology.

Impact of Gut Microbiota on the Peripheral Nervous System in Physiological, Regenerative and Pathological Conditions

It has been widely demonstrated that the gut microbiota is responsible for essential functions in human health and that its perturbation is implicated in the development and progression of a growing list of diseases. The number of studies evaluating how the gut microbiota interacts with and influences other organs and systems in the body and vice versa is constantly increasing and several 'gut-organ axes' have already been defined. Recently, the view on the link between the gut microbiota (GM) and the peripheral nervous system (PNS) has become broader by exceeding the fact that the PNS can serve as a systemic carrier of GM-derived metabolites and products to other organs. The PNS as the communication network between the central nervous system and the periphery of the body and internal organs can rather be affected itself by GM perturbation. In this review, we summarize the current knowledge about the impact of gut microbiota on the PNS, with regard to its somatic and autonomic divisions, in physiological, regenerative and pathological conditions.

The association of vitamin A, zinc and copper levels with clinical symptoms in children with autism spectrum disorders in Jilin Province, China

BACKGROUND

This study evaluated vitamin A (VA), copper (Cu), and zinc (Zn) levels in the population with autism spectrum disorder (ASD) in Jilin Province, China. Furthermore, we examined their links to core symptoms and neurodevelopment, as well as gastrointestinal (GI) comorbidities and sleep disorders.

METHODS

This study included 181 children with autism and 205 typically developing (TD) children. The participants had not taken vitamin/mineral supplements in the prior three months. High-performance liquid chromatography was used to measure serum VA levels. By using inductively coupled plasma-mass spectrometry, Zn and Cu concentrations in plasma were determined. Importantly, the Childhood Autism Rating Scale, the Social Responsiveness Scale, and the Autism Behavior Checklist were used to measure core ASD symptoms. However, the Griffith Mental Development Scales-Chinese were used to measure neurodevelopment. GI comorbidities and sleep abnormalities were assessed with the 6 Item-Gastrointestinal Severity Index and Children's Sleep Habits Questionnaire, respectively. Children with ASD with GI issues were grouped according to severity (low GI severity and high GI severity groups).

RESULTS

(i) The difference in VA, Zn, Cu levels and the Zn/Cu ratio between ASD and TD children is small. But children with ASD had lower VA levels and Zn/Cu ratio, higher Cu levels than TD children. Cu levels in children with ASD were associated with the severity of core symptoms. (ii) Children with ASD were much more likely than their TD counterparts to suffer from GI comorbidities or sleep problems. Furthermore, it was observed that high GI severity was associated with lower levels of VA, whereas low GI severity was associated with higher levels of VA. (iii) The children with ASD who had both lower VA and lower Zn/Cu ratio had more severe scores on the Autism Behavior Checklist, but not on other measures.

CONCLUSION

Children with ASD had lower VA and Zn/Cu ratio, and higher Cu levels. Cu levels in children with ASD were weakly correlated with one subscale on social or self-help. ASD children with lower VA levels may face more serious GI comorbidities. Children with ASD combined VA-Zn/Cu lower had more severe core symptoms.

TRIAL REGISTRATION

Registration number: ChiCTR-OPC-17013502. Date of registration: 2017-11-23.

An Overview on Fecal Profiles of Amino Acids and Related Amino-Derived Compounds in Children with Autism Spectrum Disorder in Tunisia

Autism spectrum disorder (ASD) is a neurodevelopmental pathology characterized by the impairment of social interaction, difficulties in communication, and repetitive behaviors. Alterations in the metabolism of amino acids have been reported. We performed a chromatographic analysis of fecal amino acids, ammonium, biogenic amines, and gamma aminobutyric acid (GABA) in Tunisian autistic children from 4 to 10 years, and results were compared with their siblings (SIB) and children from the general population (GP). ASD presented significantly higher levels of fecal amino acids than SIB and GP; differences being more pronounced in younger (4–7 years) than in older (8–10 years) individuals whereas no changes were found for the remaining compounds. Lower levels of histidine were the only difference related with severe symptoms of autism (CARS scale). A linear discriminant analysis (LDA) based on fecal amino acid profiles clearly separated ASD, SIB, and GP at 4 to 7 years but not at more advanced age (8–10 years), evidencing more pronounced alterations in younger children. The relationship of fecal amino acids with autism needs deeper research integrating blood analytical parameters, brain metabolism, and intestinal microbiota. Fecal amino acids could be targeted for designing personalized diets to prevent or minimize cognitive impairments associated with ASD.

Maternal Inflammation with Elevated Kynurenine Metabolites Is Related to the Risk of Abnormal Brain Development and Behavioral Changes in Autism Spectrum Disorder

Several studies show that genetic and environmental factors contribute to the onset and progression of neurodevelopmental disorders. Maternal immune activation (MIA) during gestation is considered one of the major environmental factors driving this process. The kynurenine pathway (KP) is a major route of the essential amino acid L-tryptophan (Trp) catabolism in mammalian cells. Activation of the KP following neuro-inflammation can generate various endogenous neuroactive metabolites that may impact brain functions and behaviors. Additionally, neurotoxic metabolites and excitotoxicity cause long-term changes in the trophic support, glutamatergic system, and synaptic function following KP activation. Therefore, investigating the role of KP metabolites during neurodevelopment will likely promote further understanding of additional pathophysiology of neurodevelopmental disorders, including autism spectrum disorder (ASD). In this review, we describe the changes in KP metabolism in the brain during pregnancy and represent how maternal inflammation and genetic factors influence the KP during development. We overview the patients with ASD clinical data and animal models designed to verify the role of perinatal KP elevation in long-lasting biochemical, neuropathological, and behavioral deficits later in life. Our review will help shed light on new therapeutic strategies and interventions targeting the KP for neurodevelopmental disorders.

SREBP modulates the NADP+/NADPH cycle to control night sleep in Drosophila

Sleep behavior is conserved throughout evolution, and sleep disturbances are a frequent comorbidity of neuropsychiatric disorders. However, the molecular basis underlying sleep dysfunctions in neurological diseases remains elusive. Using a model for neurodevelopmental disorders (NDDs), the Drosophila Cytoplasmic FMR1 interacting protein haploinsufficiency (Cyfip^85.1/+), we identify a mechanism modulating sleep homeostasis. We show that increased activity of the sterol regulatory element-binding protein (SREBP) in Cyfip^85.1/+ flies induces an increase in the transcription of wakefulness-associated genes, such as the malic enzyme (Men), causing a disturbance in the daily NADP⁺/NADPH ratio oscillations and reducing sleep pressure at the night-time onset. Reduction in SREBP or Men activity in Cyfip^85.1/+ flies enhances the NADP⁺/NADPH ratio and rescues the sleep deficits, indicating that SREBP and Men are causative for the sleep deficits in Cyfip heterozygous flies. This work suggests modulation of the SREBP metabolic axis as a new avenue worth exploring for its therapeutic potential in sleep disorders.

Neuroactive Amino Acid Profile in Autism Spectrum Disorder: Results from a Clinical Sample

Biological bases of autism spectrum disorder (ASD) include both genetic and epigenetic causes. Patients with ASD show anomalies in the profile of certain plasma amino acids, including neuroactive amino acids. Monitoring plasma amino acids may be relevant for patient care and interventions. We evaluated the plasma amino acid profile in samples extracted from dry blood spots by electrospray ionization-tandem mass spectrometry. Fourteen amino acids and eleven amino acid ratios were examined in patients with ASD and intellectual disability (ID), and neurotypical control subjects (TD). The amino acid profile in the ASD group showed reduced levels of ornithine (p = 0.008), phenylalanine (p = 0.042) and tyrosine (p = 0.013). The statistically significant amino acid ratios were Leu+Val/Phe+Tyr (p = 0.002), Tyr/Leu (p = 0.007) and Val/Phe (p = 0.028), such differences remaining significant only in the comparison between ASD and TD. Finally, a positive correlation emerged between the score of the restricted and repetitive behavior on ADOS-2 and the citrulline levels in the ASD group (p = 0.0047). To conclude, patients with ASD may show a distinguishable metabolic profile useful for studying their metabolic pathways in order to develop screening tests and targeted therapies.

In Vitro Fermentation of Edible Mushrooms: Effects on Faecal Microbiota Characteristics of Autistic and Neurotypical Children

Children with autism spectrum disorder (ASD) often suffer gastrointestinal disturbances consistent with gut microbiota (GM) alterations. Treatment with pro/prebiotics may potentially alleviate gut symptoms, but the evidence for prebiotics is scarce. This study aims to evaluate the effects of edible mushrooms (Pleurotus, Basidiomycota) and prebiotic compounds on GM composition and metabolite production in vitro, using faecal samples from autistic and non-autistic children. Specific microbial populations were enumerated after 24 h of fermentation by quantitative PCR, and the metabolic production was determined by gas chromatography. Higher levels of Prevotella spp. and Bifidobacterium spp. were measured in neurotypical children compared to ASD children. A total of 24 h fermentation of Pleurotus eryngii and P. ostreatus mushroom powder increased the levels of Bifidobacterium, while known prebiotics increased the levels of total bacteria and Bacteroides in both groups. Only P. eryngii mushrooms resulted in significantly elevated levels of total bacteria Bacteroides and Feacalibacterium prausnitzii compared to the negative control (NC) in the ASD group. Both mushrooms induced elevated levels of butyrate after 24 h of fermentation, while short-chain fructooligosaccharides induced increased levels of acetate in the ASD group, compared to NC. Overall, this study highlights the positive effect of edible mushrooms on the GM and metabolic activity of children with ASD.

Analysis of Whole Blood and Urine Trace Elements in Children with Autism Spectrum Disorders and Autistic Behaviors

The relationship between trace elements and neurological development is an emerging research focus. We performed a case-control study to explore (1) the differences of 13 trace elements chromium (Cr), manganese (Mn), cobalt (Co), zinc (Zn), arsenic (As), selenium (Se), molybdenum (Mo), cadmium (Cd), stannum (Sn), stibium (Sb), mercury (Hg), titanium (TI), and plumbum (Pb) concentration in whole blood and urine between autism spectrum disorder (ASD) children and their typical development peers, and (2) the association between the 13 trace elements and core behaviors of ASD. Thirty ASD subjects (cases) and 30 age-sex-matched healthy subjects from Baise City, Guangxi Zhuang Autonomous Region, China, were recruited. Element analysis was carried out by inductively coupled plasma-optical emission spectrometry. Autistic behaviors were assessed using Autism Behavior Checklist (ABC), Childhood Autism Rating Scale (CARS), and Children Neuropsychological and Behavior Scale (CNBS). The whole blood concentrations of Mo (p = 0.004), Cd (0.007), Sn (p = 0.003), and Pb (p = 0.037) were significantly higher in the ASD cases than in the controls. Moreover, Se (0.393), Hg (0.408), and Mn (- 0.373) concentrations were significantly correlated between whole blood and urine levels in ASD case subjects. There were significant correlations between whole blood Sb (0.406), Tl (0.365), Mo (- 0.4237), Mn (- 0.389), Zn (0.476), and Se (0.375) levels and core behaviors of ASD. Although the mechanism of trace element imbalance in ASD is unclear, these data demonstrate that core behaviors of ASD may be affected by certain trace elements. Further studies are recommended for exploring the mechanism of element imbalance and providing corresponding clinical treatment measures.

Water-soluble vitamin insufficiency, deficiency and supplementation in children and adolescents with a psychiatric disorder: a systematic review and meta-analysis

Nutrition is fundamental for brain development, but relatively little is known about water-soluble vitamin (WSV) levels and the effect of supplementation on psychiatry symptoms in children and adolescents (CAD) with psychiatric disorders. Our team systematically reviewed all studies concerning WSV abnormalities or supplementation in CAD with any psychiatric disorder. We searched for original studies published between 1990 and 15/05/2020 which were not based on retrospective chart review and which included WSV blood level measurements or investigated the effect of WSV supplementation on psychiatric symptoms in psychiatric patients aged 18 or under. Forty-two articles were included, 69% of which (N = 29) examined Autism Spectrum Disorders (ASD), with most of these assessing folate or vitamin B₁₂ supplementation (N = 22, 75.9% of ASD studies). Meta-analyses showed significantly lower vitamin B₁₂ levels in ASD and ADHD patients vs. healthy controls (HC), while folate levels were higher in ADHD patients vs. HC. Most of the studies (9/10, 90%) showed a decrease in symptoms as measured by clinical scales after supplementation. There was significant heterogeneity between the studies, however many found different types of vitamin abnormalities in CAD with psychiatric disorders.

The Rationale for Vitamin, Mineral, and Cofactor Treatment in the Precision Medical Care of Autism Spectrum Disorder

Children with autism spectrum disorder may exhibit nutritional deficiencies due to reduced intake, genetic variants, autoantibodies interfering with vitamin transport, and the accumulation of toxic compounds that consume vitamins. Importantly, vitamins and metal ions are essential for several metabolic pathways and for neurotransmitter functioning. The therapeutic benefits of supplementing vitamins, minerals (Zinc, Magnesium, Molybdenum, and Selenium), and other cofactors (coenzyme Q10, alpha-lipoic acid, and tetrahydrobiopterin) are mediated through their cofactor as well as non-cofactor functions. Interestingly, some vitamins can be safely administered at levels far above the dose typically used to correct the deficiency and exert effects beyond their functional role as enzyme cofactors. Moreover, the interrelationships between these nutrients can be leveraged to obtain synergistic effects using combinations. The present review discusses the current evidence for using vitamins, minerals, and cofactors in autism spectrum disorder, the rationale behind their use, and the prospects for future use.

The role of selenoproteins in neurodevelopment and neurological function: Implications in autism spectrum disorder

Selenium and selenoproteins play a role in many biological functions, particularly in brain development and function. This review outlines the role of each class of selenoprotein in human brain function. Most selenoproteins play a large antioxidant role within the brain. Autism spectrum disorder (ASD) has been shown to correlate with increased oxidative stress, and the presumption of selenoproteins as key players in ASD etiology are discussed. Further, current literature surrounding selenium in ASD and selenium supplementation studies are reviewed. Finally, perspectives are given for future directions of selenoprotein research in ASD.

Towards the Development of a Diagnostic Test for Autism Spectrum Disorder: Big Data Meets Metabolomics

Autism spectrum disorder (ASD) is defined as a neurodevelopmental disorder which results in impairments in social communications and interactions as well as repetitive behaviors. Despite current estimates showing that approximately 2.2% of children are affected in the United States, relatively little about ASD pathophysiology is known in part due to the highly heterogenous presentation of the disorder. Given the limited knowledge into the biological mechanisms governing its etiology, the diagnosis of ASD is performed exclusively based on an individual's behavior assessed by a clinician through psychometric tools. Although there is no readily available biochemical test for ASD diagnosis, multivariate statistical methods show considerable potential for effectively leveraging multiple biochemical measurements for classification and characterization purposes. In this work, markers associated with the folate dependent one-carbon metabolism and transulfuration (FOCM/TS) pathways analyzed via both Fisher Discriminant Analysis and Support Vector Machine showed strong capability to distinguish between ASD and TD cohorts. Furthermore, using Kernel Partial Least Squares regression it was possible to assess some degree of behavioral severity from metabolomic data. While the results presented need to be replicated in independent future studies, they represent a promising avenue for uncovering clinically relevant ASD biomarkers.

Independent and Combined Effects of Probiotics and Prebiotics as Supplements or Food-Rich Diets on a Propionic-Acid-Induced Rodent Model of Autism Spectrum Disorder

The link between nutrition and autism spectrum disorder (ASD) as a neurodevelopmental condition, which is clinically presented as significant delays or deviations in interaction and communication, has provided a fresh point of view and signals that nutrition may play a role in the etiology of ASD, as well as playing an effective role in treatment by improving symptoms. In this study, 36 male albino rat pups were used. They were randomly divided into five groups. The control group was fed only a standard diet and water for the 30 days of the experiment. The second group, which served as a propionic acid (PPA)-induced rodent model of ASD, received orally administered PPA (250 mg/kg body weight (BW)) for 3 days, followed by feeding with a standard diet until the end of the experiment. The three other groups were given PPA (250 mg/kg body weight (BW)) for 3 days and then fed a standard diet and orally administered yogurt (3 mL/kg BW/day), artichokes (400 mL/kg BW/day), and a combination of Lacticaseibacillus rhamnosus GG at 0.2 mL daily (1 × 10⁹ CFU; as the probiotic of yogurt) and luteolin (50 mg/kg BW/day; as the major antioxidant and anti-inflammatory ingredient of artichokes) for 27 days. Biochemical markers, including gamma-aminobutyric acid (GABA), reduced glutathione (GSH), glutathione peroxidase (GPx1), tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and interleukin-10 (IL-10), were measured in brain homogenates in all groups. The data showed that while PPA demonstrated oxidative stress and neuroinflammation in the treated rats, yogurt, Lacticaseibacillus rhamnosus GG as a probiotic, and luteolin as a prebiotic ingredient in artichokes were effective in alleviating the biochemical features of ASD. In conclusion, nutritional supplementation seems to be a promising intervention strategy for ASD. A combined dietary approach using pro- and prebiotics resulted in significant amelioration of most of the measured variables, suggesting that multiple interventions might be more relevant for the improvement of biochemical autistic features, as well as psychological traits. Prospective controlled trials are needed before recommendations can be made regarding the ideal ASD diet.

Trace Element Changes in the Plasma of Autism Spectrum Disorder Children and the Positive Correlation Between Chromium and Vanadium

Existing data demonstrate a significant correlation between autism spectrum disorder (ASD) and the status of biologically essential and toxic trace elements. However, there is still a lack of data on the steady state of trace elements in ASD. We performed a case-control study to explore the association between the risk of ASD and 23 trace elements in plasma. The results showed that children with ASD had considerably decreased lithium (Li), manganese (Mn), selenium (Se), barium (Ba), mercury (Hg), and tin (Sn) levels when compared to their age- and sex-matched controls. Meanwhile, children with ASD had considerably increased plasma chromium (Cr) and vanadium (V) concentrations. We also divided each group into subgroups based on age and gender and created element-related networks for each subgroup. We detected significant element correlations within or between subgroups, as well as changes in correlations that included all elements examined. Finally, more element correlations were observed among males, which may open a new avenue for understanding the complicated process behind the sex ratio of children with ASD. Overall, our data revealed a novel relationship between elements and ASD, which may extend current understanding about ASD.

Repurposing SGLT2 Inhibitors for Neurological Disorders: A Focus on the Autism Spectrum Disorder

Autism spectrum disorder (ASD) is a neurodevelopmental disorder with a substantially increasing incidence rate. It is characterized by repetitive behavior, learning difficulties, deficits in social communication, and interactions. Numerous medications, dietary supplements, and behavioral treatments have been recommended for the management of this condition, however, there is no cure yet. Recent studies have examined the therapeutic potential of the sodium-glucose cotransporter 2 (SGLT2) inhibitors in neurodevelopmental diseases, based on their proved anti-inflammatory effects, such as downregulating the expression of several proteins, including the transforming growth factor beta (TGF-β), interleukin-6 (IL-6), C-reactive protein (CRP), nuclear factor κB (NF-κB), tumor necrosis factor alpha (TNF-α), and the monocyte chemoattractant protein (MCP-1). Furthermore, numerous previous studies revealed the potential of the SGLT2 inhibitors to provide antioxidant effects, due to their ability to reduce the generation of free radicals and upregulating the antioxidant systems, such as glutathione (GSH) and superoxide dismutase (SOD), while crossing the blood brain barrier (BBB). These properties have led to significant improvements in the neurologic outcomes of multiple experimental disease models, including cerebral oxidative stress in diabetes mellitus and ischemic stroke, Alzheimer's disease (AD), Parkinson's disease (PD), and epilepsy. Such diseases have mutual biomarkers with ASD, which potentially could be a link to fill the gap of the literature studying the potential of repurposing the SGLT2 inhibitors' use in ameliorating the symptoms of ASD. This review will look at the impact of the SGLT2 inhibitors on neurodevelopmental disorders on the various models, including humans, rats, and mice, with a focus on the SGLT2 inhibitor canagliflozin. Furthermore, this review will discuss how SGLT2 inhibitors regulate the ASD biomarkers, based on the clinical evidence supporting their functions as antioxidant and anti-inflammatory agents capable of crossing the blood-brain barrier (BBB).

The Hepatic Mitochondrial Alterations Exacerbate Meta-Inflammation in Autism Spectrum Disorders

The role of the liver in autism spectrum disorders (ASD), developmental disabilities characterized by impairments in social interactions and repetitive behavioral patterns, has been poorly investigated. In ASD, it has been shown a dysregulation of gut-brain crosstalk, a communication system able to influence metabolic homeostasis, as well as brain development, mood and cognitive functions. The liver, with its key role in inflammatory and metabolic states, represents the crucial metabolic organ in this crosstalk. Indeed, through the portal vein, the liver receives not only nutrients but also numerous factors derived from the gut and visceral adipose tissue, which modulate metabolism and hepatic mitochondrial functions. Here, we investigated, in an animal model of ASD (BTBR mice), the involvement of hepatic mitochondria in the regulation of inflammatory state and liver damage. We observed increased inflammation and oxidative stress linked to hepatic mitochondrial dysfunction, steatotic hepatocytes, and marked mitochondrial fission in BTBR mice. Our preliminary study provides a better understanding of the pathophysiology of ASD and could open the way to identifying hepatic mitochondria as targets for innovative therapeutic strategies for the disease.

Microbiome in Precision Psychiatry: An Overview of the Ethical Challenges Regarding Microbiome Big Data and Microbiome-Based Interventions

There has been a spurt in both fundamental and translational research that examines the underlying mechanisms of the human microbiome in psychiatric disorders. The personalized and dynamic features of the human microbiome suggest the potential of its manipulation for precision psychiatry in ways to improve mental health and avoid disease. However, findings in the field of microbiome also raise philosophical and ethical questions. From a philosophical point of view, they may yet be another attempt at providing a biological cause for phenomena that ultimately cannot be so easily localized. From an ethical point of view, it is relevant that the human gut microbiome comprises data on the individual's lifestyle, disease history, previous medications, and mental health. Massive datasets of microbiome sequences are collected to facilitate comparative studies to identify specific links between the microbiome and mental health. Although this emerging research domain may show promise for psychiatric patients, it is surrounded by ethical challenges regarding patient privacy, health risks, effects on personal identity, and concerns about responsibility. This narrative overview displays the roles and advances of microbiome research in psychiatry and discusses the philosophical and ethical implications of microbiome big data and microbiome-based interventions for psychiatric patients. We also investigate whether these issues are really "new," or "old wine in new bottles."

Dietary Approaches and Nutritional Complexities of Autism Spectrum Disorder

Background:

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by poor social interaction, repetitive behavior, learning difficulties, cognitive issues, and unusual eating patterns. Different factors including genetic and environmental variables have been identified to increase the risk of developing ASD.

Objective:

The main objective of the present review is to investigate the dietary approaches and modifications to reduce the intricacies related to ASD.

Results:

Studies included in this review suggested that abnormalities in the gut microbiota are involved in the pathogenesis and severity of the disease. Medical nutrition therapy for ASD consists of excluding harmful food components such as gluten, casein, processed foods, and excessive sugars and increasing the consumption of omega-3 fats, vitamins and minerals, probiotics, and antioxidants. Furthermore, awareness regarding food labels might help to avoid food allergens in diet.

Conclusion:

Active dietary treatments including the use of dietary supplements and elimination of processed foods appear to reduce the complexities of ASD. Furthermore, support of health care professionals and adopting public health approaches might help to prevent adverse outcomes related to ASD. Future research is required to determine the prevalence of ASD and related outcomes in low/middle income countries as this area is highly neglected.