Sex shapes gut-microbiota-brain communication and disease.

Research into the microbiota-gut-brain axis (MGBA) has entered a golden age, raising the hope that therapeutics acting on it may offer breakthroughs in the treatment of many illnesses. However, most of this work overlooks a fundamental, yet understudied, biological variable: sex. Sex differences exist at every level of the MGBA.

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.

GMEmbeddings: An R Package to Apply Embedding Techniques to Microbiome Data.

Large-scale microbiome studies investigating disease-inducing microbial roles base their findings on differences between microbial count data in contrasting environments (e.g., stool samples between cases and controls).

An open-source, low-cost voluntary running activity tracking tool for in vivo rodent studies.

In vivo rodent behavioral and physiological studies often benefit from measurement of general activity. However, many existing instruments necessary to track such activity are high in cost and invasive within home cages, some even requiring extensive separate cage systems, limiting their widespread use to collect data. We present here a low-cost open-source alternative that measures voluntary wheel running activity and allows for modulation and customization, along with a reproducible and easy to set-up code pipeline for setup and analysis in Arduino IDE and R.

Revealing General Patterns of Microbiomes That Transcend Systems: Potential and Challenges of Deep Transfer Learning.

A growing body of research has established that the microbiome can mediate the dynamics and functional capacities of diverse biological systems. Yet, we understand little about what governs the response of these microbial communities to host or environmental changes. Most efforts to model microbiomes focus on defining the relationships between the microbiome, host, and environmental features within a specified study system and therefore fail to capture those that may be evident across multiple systems.

Longitudinal study of stool-associated microbial taxa in sibling pairs with and without autism spectrum disorder.

Autism Spectrum Disorder (ASD) is a complex neurodevelopmental disorder influenced by both genetic and environmental factors. Recently, gut dysbiosis has emerged as a powerful contributor to ASD symptoms. In this study, we recruited over 100 age-matched sibling pairs (between 2 and 8 years old) where one had an Autism ASD diagnosis and the other was developing typically (TD) (432 samples total).

The Role of the Microbiome in Autism: All That We Know about All That We Don't Know.

Autism spectrum disorder (ASD) is a remarkably complex disorder influenced by both genetic and environmental factors. Numerous microbial diversity surveys conducted over the past decade have attempted to link specific ASD biomarkers to gastrointestinal tract disturbances, but results generated across cohorts and studies remain inconsistent. This commentary discusses multidirectional interactions between the host, the microbiome, and external factors germane to autism.

Children with Autism and Their Typically Developing Siblings Differ in Amplicon Sequence Variants and Predicted Functions of Stool-Associated Microbes.

The existence of a link between the gut microbiome and autism spectrum disorder (ASD) is well established in mice, but in human populations, efforts to identify microbial biomarkers have been limited due to a lack of appropriately matched controls, stratification of participants within the autism spectrum, and sample size. To overcome these limitations, we crowdsourced the recruitment of families with age-matched sibling pairs between 2 and 7 years old (within 2 years of each other), where one child had a diagnosis of ASD and the other did not. Parents collected stool samples, provided a home video of their ASD child's natural social behavior, and responded online to diet and behavioral questionnaires.

Correction: Decoding the language of microbiomes using word-embedding techniques, and applications in inflammatory bowel disease.

[This corrects the article DOI: 10.1371/journal.pcbi.

Decoding the language of microbiomes using word-embedding techniques, and applications in inflammatory bowel disease.

Microbiomes are complex ecological systems that play crucial roles in understanding natural phenomena from human disease to climate change. Especially in human gut microbiome studies, where collecting clinical samples can be arduous, the number of taxa considered in any one study often exceeds the number of samples ten to one hundred-fold. This discrepancy decreases the power of studies to identify meaningful differences between samples, increases the likelihood of false positive results, and subsequently limits reproducibility.

Comorbid Analysis of Genes Associated with Autism Spectrum Disorders Reveals Differential Evolutionary Constraints.

The burden of comorbidity in Autism Spectrum Disorder (ASD) is substantial. The symptoms of autism overlap with many other human conditions, reflecting common molecular pathologies suggesting that cross-disorder analysis will help prioritize autism gene candidates. Genes in the intersection between autism and related conditions may represent nonspecific indicators of dysregulation while genes unique to autism may play a more causal role.

Multi-omics of permafrost, active layer and thermokarst bog soil microbiomes.

Over 20% of Earth's terrestrial surface is underlain by permafrost with vast stores of carbon that, once thawed, may represent the largest future transfer of carbon from the biosphere to the atmosphere. This process is largely dependent on microbial responses, but we know little about microbial activity in intact, let alone in thawing, permafrost. Molecular approaches have recently revealed the identities and functional gene composition of microorganisms in some permafrost soils and a rapid shift in functional gene composition during short-term thaw experiments.

FOAM (Functional Ontology Assignments for Metagenomes): a Hidden Markov Model (HMM) database with environmental focus.

A new functional gene database, FOAM (Functional Ontology Assignments for Metagenomes), was developed to screen environmental metagenomic sequence datasets. FOAM provides a new functional ontology dedicated to classify gene functions relevant to environmental microorganisms based on Hidden Markov Models (HMMs). Sets of aligned protein sequences (i.

Microbial ecology of chlorinated solvent biodegradation.

This study focused on the microbial ecology of tetrachloroethene (PCE) degradation to trichloroethene, cis-1,2-dichloroethene and vinyl chloride to evaluate the relationship between the microbial community and the potential accumulation or degradation of these toxic metabolites. Multiple soil microcosms supplied with different organic substrates were artificially contaminated with PCE. A thymidine analogue, bromodeoxyuridine (BrdU), was added to the microcosms and incorporated into the DNA of actively replicating cells.

Identification of active oxalotrophic bacteria by Bromodeoxyuridine DNA labeling in a microcosm soil experiments.

The oxalate-carbonate pathway (OCP) leads to a potential carbon sink in terrestrial environments. This process is linked to the activity of oxalotrophic bacteria. Although isolation and molecular characterizations are used to study oxalotrophic bacteria, these approaches do not give information on the active oxalotrophs present in soil undergoing the OCP.

Amino acid treatment enhances protein recovery from sediment and soils for metaproteomic studies.

Characterization of microbial protein expression provides information necessary to better understand the unique biological pathways that occur within soil microbial communities that contribute to atmospheric CO2 levels and the earth's changing climate. A significant challenge in studying the soil microbial community proteome is the initial dissociation of bacterial proteins from the complex mixture of particles found in natural soil. The differential extraction of intact bacterial cells limits the characterization of the complete representation of a microbial community.

Modeling of phenoxy acid herbicide mineralization and growth of microbial degraders in 15 soils monitored by quantitative real-time PCR of the functional tfdA gene.

Mineralization potentials, rates, and kinetics of the three phenoxy acid (PA) herbicides, 2,4-dichlorophenoxyacetic acid (2,4-D), 4-chloro-2-methylphenoxyacetic acid (MCPA), and 2-(4-chloro-2-methylphenoxy)propanoic acid (MCPP), were investigated and compared in 15 soils collected from five continents. The mineralization patterns were fitted by zero/linear or exponential growth forms of the three-half-order models and by logarithmic (log), first-order, or zero-order kinetic models. Prior and subsequent to the mineralization event, tfdA genes were quantified using real-time PCR to estimate the genetic potential for degrading PA in the soils.

In situ TCE degradation mediated by complex dehalorespiring communities during biostimulation processes.

The bioremediation of chloroethene contaminants in groundwater polluted systems is still a serious environmental challenge. Many previous studies have shown that cooperation of several dechlorinators is crucial for complete dechlorination of trichloroethene to ethene. In the present study, we used an explorative functional DNA microarray (DechloArray) to examine the composition of specific functional genes in groundwater samples in which chloroethene bioremediation was enhanced by delivery of hydrogen-releasing compounds.

Metagenomic analysis of a permafrost microbial community reveals a rapid response to thaw.

Permafrost contains an estimated 1672 Pg carbon (C), an amount roughly equivalent to the total currently contained within land plants and the atmosphere. This reservoir of C is vulnerable to decomposition as rising global temperatures cause the permafrost to thaw. During thaw, trapped organic matter may become more accessible for microbial degradation and result in greenhouse gas emissions.

Comparative phylogenetic microarray analysis of microbial communities in TCE-contaminated soils.

The arrival of chemicals in a soil or groundwater ecosystem could upset the natural balance of the microbial community. Since soil microorganisms are the first to be exposed to the chemicals released into the soil environment, we evaluated the use of a phylogenetic microarray as a bio-indicator of community perturbations due to the exposure to trichloroethylene (TCE). The phylogenetic microarray, which measures the presence of different members of the soil community, was used to evaluate unpolluted soils exposed to TCE as well as to samples from historically TCE polluted sites.

Characterization of denitrification gene clusters of soil bacteria via a metagenomic approach.

We characterized operons encoding enzymes involved in denitrification, a nitrogen-cycling process involved in nitrogen losses and greenhouse gas emission, using a metagenomic approach which combines molecular screening and pyrosequencing. Screening of 77,000 clones from a soil metagenomic library led to the identification and the subsequent characterization of nine denitrification gene clusters.

Evaluation of functional gene enrichment in a soil metagenomic clone library.

We evaluated the use of mixed oligonucleotide probes hybridized to metagenomic clones spotted on high density membranes. The pooled probes included oligonucleotides designed for genes associated with denitrification, antibiotic resistance, and dehalogenation among others. Pyrosequence comparison between the clones and the original DNA demonstrated the utility of clone screening with pooled probes.

A novel and rapid method for synthesizing positive controls and standards for quantitative PCR.

We developed and tested a method to produce DNA standards and controls for quantitative PCR by designing and performing partial hybridization of long oligonucleotides before double stranded DNA fragments were synthesized and subsequently amplified by conventional PCR. This approach does not require any natural DNA template. Applications include the production of standards, which cannot be easily produced from DNA extracted from bacteria or plants.