Publications by authors named "Justin Shaffer"

The gastrointestinal (GI) tract is innervated by intrinsic neurons of the enteric nervous system (ENS) and extrinsic neurons of the central nervous system and peripheral ganglia. The GI tract also harbors a diverse microbiome, but interactions between the ENS and the microbiome remain poorly understood. Here, we activate choline acetyltransferase (ChAT)-expressing or tyrosine hydroxylase (TH)-expressing gut-associated neurons in mice to determine effects on intestinal microbial communities and their metabolites as well as on host physiology.

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The subject of scientific literacy has never been more critical to the scientific community as well as society in general. As opportunities to spread misinformation increase with the rise of new technologies, it is critical for society to have at its disposal the means for ensuring that its citizens possess the basic scientific literacy necessary to make critical decisions on topics like climate change, biotechnology, and other science-based issues. As the Guest Editors of this themed issue of the , we present a wide array of techniques that the scientific community is using to promote scientific literacy in both academic and nonacademic settings.

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In a large cohort of 1,772 participants from the Hispanic Community Health Study/Study of Latinos with overlapping 16SV4 rRNA gene (bacterial amplicon), ITS1 (fungal amplicon), and shotgun sequencing data, we demonstrate that 16SV4 amplicon sequencing and shotgun metagenomics offer the same level of taxonomic accuracy for bacteria at the genus level even at shallow sequencing depths. In contrast, for fungal taxa, we did not observe meaningful agreements between shotgun and ITS1 amplicon results. Finally, we show that amplicon and shotgun data can be harmonized and pooled to yield larger microbiome datasets with excellent agreement (<1% effect size variance across three independent outcomes) using pooled amplicon/shotgun data compared to pure shotgun metagenomic analysis.

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Despite advances in sequencing, lack of standardization makes comparisons across studies challenging and hampers insights into the structure and function of microbial communities across multiple habitats on a planetary scale. Here we present a multi-omics analysis of a diverse set of 880 microbial community samples collected for the Earth Microbiome Project. We include amplicon (16S, 18S, ITS) and shotgun metagenomic sequence data, and untargeted metabolomics data (liquid chromatography-tandem mass spectrometry and gas chromatography mass spectrometry).

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Cancer-microbe associations have been explored for centuries, but cancer-associated fungi have rarely been examined. Here, we comprehensively characterize the cancer mycobiome within 17,401 patient tissue, blood, and plasma samples across 35 cancer types in four independent cohorts. We report fungal DNA and cells at low abundances across many major human cancers, with differences in community compositions that differ among cancer types, even when accounting for technical background.

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  • A study investigated how exposure to ambient air pollution (AAP) affects the gut microbiome of infants at 6 months, focusing on Latino mother-infant pairs in Southern California.
  • The researchers measured exposure to particulate matter (PM) and nitrogen dioxide (NO) based on where the families lived, then analyzed the infant gut microbiota using specific sequencing methods.
  • Results indicated that AAP exposure is significantly linked to changes in gut microbiota composition, which could influence infant health and development, particularly certain microbial taxa associated with systemic inflammation.
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  • Human metabolomics studies typically identify only about 10% of the molecular features present in samples.
  • The authors propose a new method that uses reference data to match metabolomics tandem mass spectrometry (MS/MS) data against annotated source data, effectively creating a pseudo-MS/MS library.
  • This new approach significantly improves the usage of MS/MS spectra by 5.1 times compared to traditional methods, enabling better analysis of dietary patterns from untargeted metabolomic data.
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Microbial communities contain a broad phylogenetic diversity of organisms; however, the majority of methods center on describing bacteria and archaea. Fungi are important symbionts in many ecosystems and are potentially important members of the human microbiome, beyond those that can cause disease. To expand our analysis of microbial communities to include data from the fungal internal transcribed spacer (ITS) region, five candidate DNA extraction kits were compared against our standardized protocol for describing bacteria and archaea using 16S rRNA gene amplicon- and shotgun metagenomics sequencing.

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Microbiome data have several specific characteristics (sparsity and compositionality) that introduce challenges in data analysis. The integration of prior information regarding the data structure, such as phylogenetic structure and repeated-measure study designs, into analysis, is an effective approach for revealing robust patterns in microbiome data. Past methods have addressed some but not all of these challenges and features: for example, robust principal-component analysis (RPCA) addresses sparsity and compositionality; compositional tensor factorization (CTF) addresses sparsity, compositionality, and repeated measure study designs; and UniFrac incorporates phylogenetic information.

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Notch-mediated lateral specification is a fundamental mechanism to resolve stochastic cell fate choices by amplifying initial differences between equivalent cells. To study how stochastic events impact Notch activity, we developed a biosensor, SALSA (sensor able to detect lateral signaling activity), consisting of an amplifying "switch"-Notch tagged with TEV protease-and a "reporter"-GFP fused to a nuclearly localized red fluorescent protein, separated by a TEVp cut site. When ligand activates Notch, TEVp enters the nucleus and releases GFP from its nuclear tether, allowing Notch activation to be quantified based on the changes in GFP subcellular localization.

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We introduce the operational genomic unit (OGU) method, a metagenome analysis strategy that directly exploits sequence alignment hits to individual reference genomes as the minimum unit for assessing the diversity of microbial communities and their relevance to environmental factors. This approach is independent of taxonomic classification, granting the possibility of maximal resolution of community composition, and organizes features into an accurate hierarchy using a phylogenomic tree. The outputs are suitable for contemporary analytical protocols for community ecology, differential abundance, and supervised learning while supporting phylogenetic methods, such as UniFrac and phylofactorization, that are seldom applied to shotgun metagenomics despite being prevalent in 16S rRNA gene amplicon studies.

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Increasing data volumes on high-throughput sequencing instruments such as the NovaSeq 6000 leads to long computational bottlenecks for common metagenomics data preprocessing tasks such as adaptor and primer trimming and host removal. Here, we test whether faster recently developed computational tools (Fastp and Minimap2) can replace widely used choices (Atropos and Bowtie2), obtaining dramatic accelerations with additional sensitivity and minimal loss of specificity for these tasks. Furthermore, the taxonomic tables resulting from downstream processing provide biologically comparable results.

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Symbiosis with bacteria is widespread among eukaryotes, including fungi. Bacteria that live within fungal mycelia (endohyphal bacteria) occur in many plant-associated fungi, including diverse Mucoromycota and Dikarya. sp.

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Conditional gene expression is a powerful tool for genetic analysis of biological phenomena. In the widely used "lox-stop-lox" approach, insertion of a stop cassette consisting of a series of stop codons and polyadenylation signals flanked by sites into the 5' untranslated region (UTR) of a gene prevents expression until the cassette is excised by tissue-specific expression of Cre recombinase. Although lox-stop-lox and similar approaches using other site-specific recombinases have been successfully used in many experimental systems, this design has certain limitations.

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Article Synopsis
  • The study investigated whether the gut microbiota of newborns affects their growth patterns during the first year of life, focusing on 132 Hispanic infants recruited at one month old.
  • Researchers used advanced sequencing to analyze the gut microbiome and assessed infant growth through weight-for-age z-scores (WAZ), weight-for-length z-scores (WLZ), and BMI.
  • Findings revealed that a more diverse gut microbiota in newborns was linked to rapid growth, with specific microbial groups identified as influential, suggesting that gut health plays a crucial role in early growth trajectories.
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This study integrates theories of achievement motivation and emotion to investigate daily academic behavior in an undergraduate online course. Using cluster analysis and hierarchical logistic regression, we analyze profiles of task values and anticipated emotions to understand expectations and completion of academic tasks over the duration of a week. Students' task specific interest, opportunity cost, and anticipated satisfaction and regret varied across tasks and were predictive of both their expectations of task completion and actual task completion reported the following day.

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  • * Researchers analyzed samples from 972 individuals and surfaces in hospitals, revealing that 16% of surfaces had detectable SARS-CoV-2 RNA, with the highest prevalence found on floors near patient beds.
  • * A specific type of bacteria from the genus Rothia was identified as a strong predictor of SARS-CoV-2 presence across various sample types, highlighting the complex interactions between bacteria and viral infections in medical environments.
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Anxiety can impact overall performance and persistence in college. Student response systems (SRSs), real-time active-learning technologies used to engage students and gauge their understanding, have been shown to elicit anxiety for some students. Kahoot! is an SRS technology that differs from others in that it involves gamification, the use of gamelike elements.

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Microbiome samples are inherently defined by the environment in which they are found. Therefore, data that provide context and enable interpretation of measurements produced from biological samples, often referred to as metadata, are critical. Important contributions have been made in the development of community-driven metadata standards; however, these standards have not been uniformly embraced by the microbiome research community.

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One goal of microbial ecology researchers is to capture the maximum amount of information from all organisms in a sample. The recent COVID-19 pandemic, caused by the RNA virus SARS-CoV-2, has highlighted a gap in traditional DNA-based protocols, including the high-throughput methods the authors previously established as field standards. To enable simultaneous SARS-CoV-2 and microbial community profiling, the authors compared the relative performance of two total nucleic acid extraction protocols with the authors' previously benchmarked protocol.

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Background: Determining the role of fomites in the transmission of SARS-CoV-2 is essential in the hospital setting and will likely be important outside of medical facilities as governments around the world make plans to ease COVID-19 public health restrictions and attempt to safely reopen economies. Expanding COVID-19 testing to include environmental surfaces would ideally be performed with inexpensive swabs that could be transported safely without concern of being a source of new infections. However, CDC-approved clinical-grade sampling supplies and techniques using a synthetic swab are expensive, potentially expose laboratory workers to viable virus and prohibit analysis of the microbiome due to the presence of antibiotics in viral transport media (VTM).

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