Autism-related dietary preferences mediate autism-gut microbiome associations.

There is increasing interest in the potential contribution of the gut microbiome to autism spectrum disorder (ASD). However, previous studies have been underpowered and have not been designed to address potential confounding factors in a comprehensive way. We performed a large autism stool metagenomics study (n = 247) based on participants from the Australian Autism Biobank and the Queensland Twin Adolescent Brain project. We found negligible direct associations between ASD diagnosis and the gut microbiome. Instead, our data support a model whereby ASD-related restricted interests are associated with less-diverse diet, and in turn reduced microbial taxonomic diversity and looser stool consistency. In contrast to ASD diagnosis, our dataset was well powered to detect microbiome associations with traits such as age, dietary intake, and stool consistency. Overall, microbiome differences in ASD may reflect dietary preferences that relate to diagnostic features, and we caution against claims that the microbiome has a driving role in ASD.

Semantic segmentation for fully automated macrofouling analysis on coatings after field exposure.

Biofouling is a major challenge for sustainable shipping, filter membranes, heat exchangers, and medical devices. The development of fouling-resistant coatings requires the evaluation of their effectiveness. Such an evaluation is usually based on the assessment of fouling progression after different exposure times to the target medium (e.g. salt water). The manual assessment of macrofouling requires expert knowledge about local fouling communities due to high variances in phenotypical appearance, has single-image sampling inaccuracies for certain species, and lacks spatial information. Here an approach for automatic image-based macrofouling analysis was presented. A dataset with dense labels prepared from field panel images was made and a convolutional network (adapted U-Net) for the semantic segmentation of different macrofouling classes was proposed. The establishment of macrofouling localization allows for the generation of a successional model which enables the determination of direct surface attachment and in-depth epibiotic studies.

Immune Signature Against Plasmodium falciparum Antigens Predicts Clinical Immunity in Distinct Malaria Endemic Communities.

A large body of evidence supports the role of antibodies directed against the Plasmodium spp. parasite in the development of naturally acquired immunity to malaria, however an antigen signature capable of predicting protective immunity against Plasmodium remains to be identified. Key challenges for the identification of a predictive immune signature include the high dimensionality of data produced by high-throughput technologies and the limitation of standard statistical tests in accounting for synergetic interactions between immune responses to multiple targets. In this study, using samples collected from young children in Ghana at multiple time points during a longitudinal study, we adapted a predictive modeling framework which combines feature selection and machine learning techniques to identify an antigen signature of clinical immunity to malaria. Our results show that an individual's immune status can be accurately predicted by measuring antibody responses to a small defined set of 15 target antigens. We further demonstrate that the identified immune signature is highly versatile and capable of providing precise and accurate estimates of clinical protection from malaria in an independent geographic community. Our findings pave the way for the development of a robust point-of-care test to identify individuals at high risk of disease and which could be applied to monitor the impact of vaccinations and other interventions. This approach could be also translated to biomarker discovery for other infectious diseases.

Whole-genome sequence of the bovine blood fluke Schistosoma bovis supports interspecific hybridization with S. haematobium.

Mesenteric infection by the parasitic blood fluke Schistosoma bovis is a common veterinary problem in Africa and the Middle East and occasionally in the Mediterranean Region. The species also has the ability to form interspecific hybrids with the human parasite S. haematobium with natural hybridisation observed in West Africa, presenting possible zoonotic transmission. Additionally, this exchange of alleles between species may dramatically influence disease dynamics and parasite evolution. We have generated a 374 Mb assembly of the S. bovis genome using Illumina and PacBio-based technologies. Despite infecting different hosts and organs, the genome sequences of S. bovis and S. haematobium appeared strikingly similar with 97% sequence identity. The two species share 98% of protein-coding genes, with an average sequence identity of 97.3% at the amino acid level. Genome comparison identified large continuous parts of the genome (up to several 100 kb) showing almost 100% sequence identity between S. bovis and S. haematobium. It is unlikely that this is a result of genome conservation and provides further evidence of natural interspecific hybridization between S. bovis and S. haematobium. Our results suggest that foreign DNA obtained by interspecific hybridization was maintained in the population through multiple meiosis cycles and that hybrids were sexually reproductive, producing viable offspring. The S. bovis genome assembly forms a highly valuable resource for studying schistosome evolution and exploring genetic regions that are associated with species-specific phenotypic traits.

Fully Convolutional Neural Network for Detection and Counting of Diatoms on Coatings after Short-Term Field Exposure.

While the use of deep learning is a valuable technology for automatic detection systems for medical data and images, the biofouling community is still lacking an analytical tool for the detection and counting of diatoms on samples after short-term field exposure. In this work, a fully convolutional neural network was implemented as a fast and simple approach to detect diatoms on two-channel (fluorescence and phase-contrast) microscopy images by predicting bounding boxes. The developed approach performs well with only a small number of trainable parameters and a F1 score of 0.82. Counting diatoms was evaluated on a data set of 600 microscopy images of three different surface chemistries (hydrophilic and hydrophobic) and is very similar to counting by humans while demanding only a fraction of the analysis time.

Whole-genome sequencing of human malignant mesothelioma tumours and cell lines.

Pleural mesothelioma is a cancer of serosal surfaces caused by environmental exposure to asbestos. Clinical outcome remains poor and while trials of new treatments are ongoing it remains an understudied cancer. Mesothelioma cell lines can readily be grown from primary tumour and from tumour cells shed into pleural effusion with the latter representing a particularly valuable source of DNA in clinical settings, procurable without the need for additional invasive procedures. However, it is not well understood how accurately patient-derived cultured tumour cells represent the molecular characteristics of their primary tumour. We used whole-genome sequencing of primary tumour and matched cultured cells to comprehensively characterize mutations and structural alterations. Most cases had complex rearranged genomes with evidence of chromoanagenesis and rearrangements reminiscent of chromoplexy. Many of the identified driver mutations were structural, indicating that mesothelioma is often caused by structural alterations and catastrophic genomic events, rather than point mutations. Because the majority of genomic changes detected in tumours were also displayed by the genomes of cultured tumour cells, we conclude that low-passage cultured tumour cells are generally suitable for molecular characterization of mesothelioma and may be particularly useful where tissue samples with high tumour cell content are not available. However, the subclonal compositions of the cell lines did not fully recapitulate the subclonal diversity of the primary tumours. Furthermore, longitudinal acquisition of major alterations in subclonal cell populations was observed after long-term passaging. These two factors define limitations of tumour-derived cell lines as genomic substrate for clinical purposes.

Vitamin D and the gut microbiome: a systematic review of in vivo studies.

PURPOSE: Variation in the human microbiome has been linked with a variety of physiological functions, including immune regulation and metabolism and biosynthesis of vitamins, hormones, and neurotransmitters. Evidence for extraskeletal effects of vitamin D has been accruing and it has been suggested that the effect of vitamin D on health is partially mediated through the microbiome. We aimed to critically evaluate the evidence linking vitamin D and the gastrointestinal microbiome. METHODS: We systematically searched the Embase, Web of Science, PubMed and CINAHL databases, including peer-reviewed publications that reported an association between a measure of vitamin D and the gastrointestinal microbiome in humans or experimental animals. RESULTS: We included 10 mouse and 14 human studies. Mouse studies compared mice fed diets containing different levels of vitamin D (usually high versus low), or vitamin D receptor knockout or Cyp27B1 knockout with wild-type mice. Five mouse studies reported an increase in Bacteroidetes (or taxa within that phylum) in the low vitamin D diet or gene knockout group. Human studies were predominantly observational; all but two of the included studies found some association between vitamin D and the gut microbiome, but the nature of differences observed varied across studies. CONCLUSIONS: Despite substantial heterogeneity, we found evidence to support the hypothesis that vitamin D influences the composition of the gastrointestinal microbiome. However, the research is limited, having been conducted either in mice or in mostly small, selected human populations. Future research in larger population-based studies is needed to fully understand the extent to which vitamin D modulates the microbiome.

Microbiota and Body Composition During the Period of Complementary Feeding.

OBJECTIVES: This study aimed to explore the associations between food group intake, faecal microbiota profile, and body composition during the period of complementary feeding. METHODS: Diet was assessed using a quantitative food frequency questionnaire, faecal microbiota profile was assessed using 16S rRNA gene sequencing, and body composition was assessed using bioelectrical impedance analysis and dual energy x-ray absorptiometry, in a cohort of 50 infants aged 6 to 24 months of age. RESULTS: During this critical period of microbiota development, age was the strongest predictor of microbiota composition with network analysis revealing a cluster of genera positively associated with age. A separate cluster comprised genera associated with fat mass index with Bifidobacterium showing the strongest correlation with fat mass index (rho = 0.55, P = 0.001, false discovery rate [FDR] = 0.018). Dairy intake was both negatively correlated with Bacteroides (rho = -0.49, P < 0.001, FDR = 0.024) and positively correlated with lean mass index (rho = 0.44, P = 0.007, FDR = 0.024). Antibiotics use in the first month of life had the most striking influence on body composition and was associated with an increase in mean body mass index z score of 1.17 (P = 0.001) and body fat of 3.5% (P = 0.001). CONCLUSIONS: Our results suggested that antibiotics use in the first month of life had the most striking influence on body composition in this cohort of infants aged 6 to 24 months, whereas dairy intake interacted with both microbiota and body composition in early life.

Patterns of Interindividual Variability in the Antibody Repertoire Targeting Proteins Across the Epstein-Barr Virus Proteome.

Background: Little is known about variation in antibody responses targeting the full spectrum of Epstein-Barr virus (EBV) proteins and how such patterns inform disease risk. Methods: We used a microarray to measure immunoglobulin G (IgG) and immunoglobulin A (IgA) antibody responses against 199 EBV protein sequences from 5 EBV strains recovered from 289 healthy adults from Taiwan. We described positivity patterns, estimated the correlation between antibodies, and investigated the associations between environmental and genetic risk factors and variations in antibody responses. Results: Healthy adults were more likely to mount IgG antibody responses to EBV proteins (median positivity frequency, 46.5% for IgG and 17.3% for IgA; P = 1.6 × 10-46, by the Wilcoxon rank sum test). Responses against glycoproteins were particularly prevalent. The correlations between antibody responses of the same class were higher than correlations across classes. The mucosal exposure to proteins involved in EBV reactivation (as determined by the IgA response) was associated with smoking (P = .002, by the sequence kernel association test-combined), and approximately one quarter of adults displayed antibody responses associated with EBV-related cancer risk. Conclusions: These data comprehensively define the variability in human IgG and IgA antibody responses to the EBV proteome. Patterns observed can serve as the foundation for elucidating which individuals are at highest risk of EBV-associated clinical conditions and for identifying targets for effective immunodiagnostic tests.

Calypso: a user-friendly web-server for mining and visualizing microbiome-environment interactions.

Calypso is an easy-to-use online software suite that allows non-expert users to mine, interpret and compare taxonomic information from metagenomic or 16S rDNA datasets. Calypso has a focus on multivariate statistical approaches that can identify complex environment-microbiome associations. The software enables quantitative visualizations, statistical testing, multivariate analysis, supervised learning, factor analysis, multivariable regression, network analysis and diversity estimates. Comprehensive help pages, tutorials and videos are provided via a wiki page. Availability and Implementation: The web-interface is accessible via http://cgenome.net/calypso/ . The software is programmed in Java, PERL and R and the source code is available from Zenodo ( https://zenodo.org/record/50931 ). The software is freely available for non-commercial users. Contact: l.krause@uq.edu.au. Supplementary information: Supplementary data are available at Bioinformatics online.

Male-specific Association Between Fat-Free Mass Index and Fecal Microbiota in 2- to 3-Year-Old Australian Children.

OBJECTIVES: Maturation of the gut microbiota has been shown to influence childhood growth, whereas alterations in microbiota composition are proposed to be causally related to the development of overweight and obesity. The objective of this study is to explore the association between microbiota profile, body size, and body composition in young children. METHODS: Fecal microbiota was examined by 16S rRNA gene sequencing, whereas body composition was assessed using the deuterium oxide dilution technique in a cohort of 37 well-nourished 2- to 3-year-old Australian children. RESULTS: Microbiota composition (weighted UniFrac distance) was shown to be significantly associated with FFMI (fat-free mass index) z score (P = 0.027, adonis) in boys but not girls. In boys, FFMI z score was significantly correlated with the relative abundance of an OUT (Operational Taxonomic Unit) belonging to the Ruminococcaceae family (Rho = 0.822, P < 0.001, pFDR (false discovery rate adjusted P value) = 0.002, n = 18). At a FDR <0.2, FFMI z score in boys was positively associated with the relative abundance of OTU related to Dorea formicigenerans and Faecalibacterium prausnitzii and negatively correlated to an OTU related to Bacteroides cellulosilyticus. CONCLUSIONS: These results suggest that previously reported associations between microbiota composition and body size may be driven by an association with fat-free mass, particularly in males.

Growth and protein-rich food intake in infancy is associated with fat-free mass index at 2-3 years of age.

AIM: The reduction of infant protein intake and associated growth velocity is a recommended public health strategy for reducing the risk of childhood obesity. This study tests the hypothesis that infants' growth and protein-rich food (dairy, meat, fish and egg) intake influences childhood body size and composition at 2-3 years of age. METHODS: Thirty-six children were studied from the Feeding Queensland Babies Study Cohort, which prospectively collected data on infant growth and diet. Body composition was estimated using the deuterium oxide dilution technique at 2-3 years of age. RESULTS: Fat-free mass index Z score at 2-3 years of age was positively associated with animal protein food (dairy, meat, fish and egg) intake at 12 months of age (r = 0.58, P = 0.002, false discovery rate corrected P value = 0.008) and negatively associated with weight-for-length growth velocity from 6 to 12 months of age (r = -0.75, P = 0.019, false discovery rate corrected P value = 0.038), which in turn was negatively associated with growth velocity from 0 to 6 months of age (r = -0.790, P = 0.007). CONCLUSION: This study suggests that strategies to reduce protein intake and growth velocity in early life may limit fat-free mass growth, potentially predisposing to increased adiposity in later life.

Long-term Health-related Quality of Life Following Esophagectomy: A Nonrandomized Comparison of Thoracoscopically Assisted and Open Surgery.

OBJECTIVE: The aim of this study was to assess long-term health-related quality of life (HRQL) in patients after thoracoscopic and open esophagectomy. SUMMARY OF BACKGROUND DATA: Trials comparing minimally invasive with open transthoracic esophagectomy have shown improved short-term outcomes; however, long-term HRQL data are lacking. This prospective nonrandomized study compared HRQL and survival after thoracoscopically assisted McKeown esophagectomy (TAMK) and open transthoracic Ivor Lewis esophagectomy (TTIL) for esophageal or gastroesophageal junction (GEJ) cancer. METHODS: Patients with esophageal or GEJ cancer selected for TAMK or TTIL completed baseline and follow-up HRQL assessments for up to 24 months using the EORTC generic and disease-specific measures, QLQ-C30 and QLQ-OES18. Baseline clinical variables were examined between the treatment groups and changes in mean HRQL scores over time estimated and tested using generalised estimating equations with propensity score (generated by boosted regression) adjustment. RESULTS: Of the 487 patients, 377 underwent TAMK and 110 underwent TTIL. Most clinical variables were similar in the 2 groups; however, there were significantly more patients with AJCC stage 3 disease who underwent TTIL than TAMK (54% vs 32%, P < 0.01) and this was reflected in the survival data.Mean symptom scores for pain were significantly higher in the TTIL group than in TAMK for 2 years postoperatively (P = 0.036). In addition, mean constipation scores were significantly higher for the TTIL group, with a 15-point difference in mean score at 3 months postoperatively (P = 0.037). CONCLUSIONS: This large comprehensive nonrandomized analysis of longitudinal HRQL shows that TTIL is associated with more pain and constipation than TAMK.

Identification of the CIMP-like subtype and aberrant methylation of members of the chromosomal segregation and spindle assembly pathways in esophageal adenocarcinoma.

The incidence of esophageal adenocarcinoma (EAC) has risen significantly over recent decades. Although survival has improved, cure rates remain poor, with <20% of patients surviving 5 years. This is the first study to explore methylome, transcriptome and ENCODE data to characterize the role of methylation in EAC. We investigate the genome-wide methylation profile of 250 samples including 125 EAC, 19 Barrett's esophagus (BE), 85 squamous esophagus and 21 normal stomach. Transcriptome data of 70 samples (48 EAC, 4 BE and 18 squamous esophagus) were used to identify changes in methylation associated with gene expression. BE and EAC showed similar methylation profiles, which differed from squamous tissue. Hypermethylated sites in EAC and BE were mainly located in CpG-rich promoters. A total of 18575 CpG sites associated with 5538 genes were differentially methylated, 63% of these genes showed significant correlation between methylation and mRNA expression levels. Pathways involved in tumorigenesis including cell adhesion, TGF and WNT signaling showed enrichment for genes aberrantly methylated. Genes involved in chromosomal segregation and spindle formation were aberrantly methylated. Given the recent evidence that chromothripsis may be a driver mechanism in EAC, the role of epigenetic perturbation of these pathways should be further investigated. The methylation profiles revealed two EAC subtypes, one associated with widespread CpG island hypermethylation overlapping H3K27me3 marks and binding sites of the Polycomb proteins. These subtypes were supported by an independent set of 89 esophageal cancer samples. The most hypermethylated tumors showed worse patient survival.

Genome-wide analysis of esophageal adenocarcinoma yields specific copy number aberrations that correlate with prognosis.

The incidence of esophageal adenocarcinoma (EAC) has been increasing rapidly for the past 3 decades in Western (Caucasian) populations. Curative treatment is based around esophagectomy, which has a major impact on quality of life. For those suitable for treatment with curative intent, 5-year survival is ∼30%. More accurate prognostic tools are therefore needed, and copy number aberrations (CNAs) may offer the ability to act as prospective biomarkers in this regard. We performed a genome-wide examination of CNAs in 54 samples of EAC using single-nucleotide polymorphism (SNP) arrays. Our aims were to describe frequent regions of CNA, to define driver CNAs, and to identify CNAs that correlated with survival. Regions of frequent amplification included oncogenes such as EGFR, MYC, KLF12, and ERBB2, while frequently deleted regions included tumor suppressor genes such as CDKN2A/B, PTPRD, FHIT, and SMAD4. The genomic identification of significant targets in cancer (GISTIC) algorithm identified 24 regions of gain and 28 regions of loss that were likely to contain driver changes. We discovered 61 genes in five regions that, when stratified by CNA type (gain or loss), correlated with a statistically significant difference in survival. Pathway analysis of the genes residing in both the GISTIC and prognostic regions showed they were significantly enriched for cancer-related networks. Finally, we discovered that copy-neutral loss of heterozygosity is a frequent mechanism of CNA in genes currently targetable by chemotherapy, potentially leading to under-reporting of cases suitable for such treatment.

Impact of experimental hookworm infection on the human gut microbiota.

The interactions between gastrointestinal parasitic helminths and commensal bacteria are likely to play a pivotal role in the establishment of host-parasite cross-talk, ultimately shaping the development of the intestinal immune system. However, little information is available on the impact of infections by gastrointestinal helminths on the bacterial communities inhabiting the human gut. We used 16S rRNA gene amplification and pyrosequencing to characterize, for the first time to our knowledge, the differences in composition and relative abundance of fecal microbial communities in human subjects prior to and following experimental infection with the blood-feeding intestinal hookworm, Necator americanus. Our data show that, although hookworm infection leads to a minor increase in microbial species richness, no detectable effect is observed on community structure, diversity or relative abundance of individual bacterial species.

Pyrosequencing reveals transient cystic fibrosis lung microbiome changes with intravenous antibiotics.

Chronic airway infection in adults with cystic fibrosis (CF) is polymicrobial and the impact of intravenous antibiotics on the bacterial community composition is poorly understood. We employed culture-independent molecular techniques to explore the early effects of i.v. antibiotics on the CF airway microbiome. DNA was extracted from sputum samples collected from adult subjects with CF at three time-points (before starting treatment, and at day 3 and day 8-10 of i.v. antibiotics) during treatment of an infective pulmonary exacerbation. Microbial community profiles were derived through analysis of bacterial-derived 16S ribosomal RNA by pyrosequencing and changes over time were compared. 59 sputum samples were collected during 24 pulmonary exacerbations from 23 subjects. Between treatment onset and day 3 there was a significant reduction in the relative abundance of Pseudomonas and increased microbial diversity. By day 8-10, bacterial community composition was similar to pre-treatment. Changes in community composition did not predict improvements in lung function. The relative abundance of Pseudomonas falls rapidly in subjects with CF receiving i.v. antibiotic treatment for a pulmonary exacerbation and is accompanied by an increase in overall microbial diversity. However, this effect is not maintained beyond the first week of treatment.

Infection with the carcinogenic liver fluke Opisthorchis viverrini modifies intestinal and biliary microbiome.

Opisthorchis viverrini is a fish-borne trematode endemic in East Asia. Following ingestion, the flukes locate to the biliary tre where chronic infection frequently leads to cholangiocarcinoma (CCA). The mechanisms by which O. viverrini infection culminates in CCA remain unknown. An unexplored aspect is its influence on the host microbiome. In the hamster, infection with this pathogen reliably leads to CCA. Genomic DNAs of microbiota from colorectal contents and bile of hamsters and from whole O. viverrini were examined in this model of fluke-induced CCA. Microbial communities were characterized by high-throughput sequencing of variable regions 7-9 of prokaryotic 16S ribosomal DNA. Of ∼1 million sequences, 536,009 with useable reads were assignable to 29,776 operational taxonomy units (OTUs) and, in turn, to 20 phyla and 273 genera of Bacteria or Archaea. Microbial community analyses revealed that fluke infection perturbed the gastrointestinal tract microbiome, increasing Lachnospiraceae, Ruminococcaceae, and Lactobacillaceae, while decreasing Porphyromonadaceae, Erysipelotrichaceae, and Eubacteriaceae (P≤0.05). More than 60 OTUs were detected in the biliary system, which confirmed bacteriobilia and a noteworthy community of microbes associated with the parasites. The fluke-associated microorganisms included potential pathogens from the Enterobacteriaceae and Listeriaceae and others, including Cyanobacteria and Deinococci, usually found in external environments. Given that opisthorchiasis is distinguished from other helminth infections by a robust inflammatory phenotype with conspicuously elevated IL-6, and that inflammation of the biliary system leads to periductal fibrosis, which is a precursor of CCA, the flukes and their microbiota may together drive this distinctive immune response.

Spatial intra-tumour heterogeneity and treatment-induced genomic evolution in oesophageal adenocarcinoma: implications for prognosis and therapy.

BACKGROUND: Oesophageal adenocarcinoma (OAC) is a highly heterogeneous cancer with poor survival. Standard curative treatment is chemotherapy with or without radiotherapy followed by oesophagectomy. Genomic heterogeneity is a feature of OAC and has been linked to treatment resistance. METHODS: Whole-genome sequencing data from 59 treatment-naïve and 18 post-treatment samples from 29 OAC patients was analysed. Twenty-seven of these were enrolled in the DOCTOR trial, sponsored by the Australasian Gastro-Intestinal Trials Group. Two biopsies from each treatment-naïve tumour were assessed to define 'shared' (between both samples) and 'private' (present in one sample) mutations. RESULTS: Mutational signatures SBS2/13 (APOBEC) and SBS3 (BRCA) were almost exclusively detected in private mutation populations of treatment-naïve tumours. Patients presenting these signatures had significantly worse disease specific survival. Furthermore, mutational signatures associated with platinum-based chemotherapy treatment as well as high platinum enrichment scores were only detected in post-treatment samples. Additionally, clones with high putative neoantigen binding scores were detected in some treatment-naïve samples suggesting immunoediting of clones. CONCLUSIONS: This study demonstrates the high intra-tumour heterogeneity in OAC, as well as indicators for treatment-induced changes during tumour evolution. Intra-tumour heterogeneity remains a problem for successful treatment strategies in OAC.