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Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by heterogeneous cognitive, behavioral and communication impairments. Disruption of the gut–brain axis (GBA) has been implicated in ASD although with limited reproducibility across studies. In this study, we developed a Bayesian differential ranking algorithm to identify ASD-associated molecular and taxa profiles across 10 cross-sectional microbiome datasets and 15 other datasets, including dietary patterns, metabolomics, cytokine profiles and human brain gene expression profiles. We found a functional architecture along the GBA that correlates with heterogeneity of ASD phenotypes, and it is characterized by ASD-associated amino acid, carbohydrate and lipid profiles predominantly encoded by microbial species in the genera Prevotella, Bifidobacterium, Desulfovibrioand Bacteroidesand correlates with brain gene expression changes, restrictive dietary patterns and pro-inflammatory cytokine profiles. The functional architecture revealed in age-matched and sex-matched cohorts is not present in sibling-matched cohorts. We also show a strong association between temporal changes in microbiome composition and ASD phenotypes. In summary, we propose a framework to leverage multi-omic datasets from well-defined cohorts and investigate how the GBA influences ASD.

Background: Systemic lupus erythematosus (SLE) is linked to host gut dysbiosis. Here we performed faecal gut microbiome sequencing to investigate SLE-pathogenic gut microbes and their potential mechanisms. Methods: There were 134 healthy controls (HCs) and 114 SLE cases for 16 S ribosomal RNA (rRNA) sequencing and 97 HCs and 124 SLE cases for shotgun metagenomics. Faecal microbial changes and associations with clinical phenotypes were evaluated, and SLE-associated microbial genera were identified in amplicon analysis. Next, metagenomic sequencing was applied for accurate identification of microbial species and discovery of their metabolic pathways and immunogenic peptides both relevant to SLE. Finally, contribution of specific taxa to disease development was confirmed by oral gavage into lupus-prone MRL/lprmice. Results: SLE patients had gut microbiota richness reduction and composition alteration, particularly lupus nephritis and active patients. Proteobacteria/Bacteroidetes(P/B) ratio was remarkably up-regulated, and Escherichiawas identified as the dominantly expanded genus in SLE, followed by metagenomics accurately located Escherichia coliand Escherichiaunclassified species. Significant associations primarily appeared among Escherichia coli, metabolic pathways of purine nucleotide salvage or peptidoglycan maturation and SLE disease activity index (SLEDAI), and between multiple epitopes from Escherichia coliand disease activity or renal involvement phenotype. Finally, gavage with faecal Escherichiarevealed that it upregulated lupus-associated serum traits and aggravated glomerular lesions in MRL/lprmice. Conclusion: We characterize a novel SLE exacerbating Escherichiaoutgrowth and suggest its contribution to SLE procession may be partially associated with metabolite changes and cross-reactivity of gut microbiota-associated epitopes and host autoantigens. The findings could provide a deeper insight into gut Escherichiain the procession of SLE.

Autism spectrum disorder (ASD) is a neurodevelopmental disorder with considerable clinical and genetic heterogeneity. In this study, we identified all classes of genomic variants from whole-genome sequencing (WGS) dataset of 32 Chinese trios with ASD, including de novomutations, inherited variants, copy number variants (CNVs) and genomic structural variants. A higher mutation rate (Poisson test, P < 2.2 × 10−16) in exonic (1.37 × 10−8) and 3′-UTR regions (1.42 × 10−8) was revealed in comparison with that of whole genome (1.05 × 10−8). Using an integrated model, we identified 87 potentially risk genes (P < 0.01) from 4832 genes harboring various rare deleterious variants, including CHD8and NRXN2, implying that the disorders may be in favor to multiple-hit. In particular, frequent rare inherited mutations of several microcephaly-associated genes (ASPM, WDR62, and ZNF335) were found in ASD. In chromosomal structure analyses, we found four de novoCNVs and one de novochromosomal rearrangement event, including a de novoduplication of UBE3A-containing region at 15q11.2-q13.1, which causes Angelman syndrome and microcephaly, and a disrupted TNRdue to de novochromosomal translocation t(1; 5)(q25.1; q33.2). Taken together, our results suggest that abnormalities of centrosomal function and chromatin remodeling of the microcephaly-associated genes may be implicated in pathogenesis of ASD. Adoption of WGS as a new yet efficient technique to illustrate the full genetic spectrum in complex disorders, such as ASD, could provide novel insights into pathogenesis, diagnosis and treatment.

AbstractBackground:Supplementation of folic acid by pregnant mothers is thought to lower the risk of autism spectrum disorders (ASDs) in the offspring. Folic acid is taken up by cells via receptors with high affinity for folate and reduced folic acid derivatives. However, this is blocked by the presence of folate receptor autoantibodies (FRAA). Cerebral FRAA have been detected with high frequency in children with ASDs, suggesting the existence of a link between folic acid uptake and disease aetiology.Methods:We investigated the frequency of FRAA in serum samples from 40 children with ASDs and 42 gender- and age-matched children with typical development (TD). Serum FRAA concentrations were measured by enzyme-linked immunosorbent assay.Results:We found a significant difference in the frequency of serum FRAA in the two study cohorts. Serum FRAA were present in 77.5% (31/40) of children with ASDs compared with 54.8% (23/42) of TD children (p = 0.03746, Fischer’s exact test). Thus, serum FRAA are more prevalent in children with ASDs than in TD children.Conclusions:Our data suggest that children with ASDs may have defects in folic acid absorption that play a role in the onset of ASDs.