Publications by authors named "J C Wootton"

289 Publications

The Pediatric Obesity Microbiome and Metabolism Study (POMMS): Methods, Baseline Data, and Early Insights.

Obesity (Silver Spring) 2021 Mar;29(3):569-578

Department of Pediatrics, Duke University, Durham, North Carolina, USA.

Objective: The purpose of this study was to establish a biorepository of clinical, metabolomic, and microbiome samples from adolescents with obesity as they undergo lifestyle modification.

Methods: A total of 223 adolescents aged 10 to 18 years with BMI ≥95th percentile were enrolled, along with 71 healthy weight participants. Clinical data, fasting serum, and fecal samples were collected at repeated intervals over 6 months. Herein, the study design, data collection methods, and interim analysis-including targeted serum metabolite measurements and fecal 16S ribosomal RNA gene amplicon sequencing among adolescents with obesity (n = 27) and healthy weight controls (n = 27)-are presented.

Results: Adolescents with obesity have higher serum alanine aminotransferase, C-reactive protein, and glycated hemoglobin, and they have lower high-density lipoprotein cholesterol when compared with healthy weight controls. Metabolomics revealed differences in branched-chain amino acid-related metabolites. Also observed was a differential abundance of specific microbial taxa and lower species diversity among adolescents with obesity when compared with the healthy weight group.

Conclusions: The Pediatric Metabolism and Microbiome Study (POMMS) biorepository is available as a shared resource. Early findings suggest evidence of a metabolic signature of obesity unique to adolescents, along with confirmation of previously reported findings that describe metabolic and microbiome markers of obesity.
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March 2021

Evaluating the efficacy of three carrier screening workflows designed to identify at-risk carrier couples.

Prenat Diagn 2021 Jan 15. Epub 2021 Jan 15.

Myriad Women's Health, South San Francisco, California, USA.

Objective: To evaluate the efficacy of three different carrier screening workflows designed to identify couples at risk for having offspring with autosomal recessive conditions.

Methods: Partner testing compliance, unnecessary testing, turnaround time, and ability to identify at-risk couples (ARCs) were measured across all three screening strategies (sequential, tandem, or tandem reflex).

Results: A total of 314,100 individuals who underwent carrier screening were analyzed. Sequential, tandem, and tandem reflex screening yielded compliance frequencies of 25.8%, 100%, and 95.9%, respectively. Among 14,595 couples tested in tandem, 42.2% of females were screen-negative, resulting in unnecessary testing of the male partner. In contrast, less than 1% of tandem reflex couples included unnecessary male testing. The median turnaround times were 29.2 days (sequential), 8 days (tandem), and 13.3 days (tandem reflex). The proportion of ARCs detected per total number of individual screens were 0.5% for sequential testing and 1.3% for both tandem and tandem reflex testing.

Conclusion: The tandem reflex strategy simplifies a potentially complex clinical scenario by providing a mechanism by which providers can maximize partner compliance and the detection of at-risk couples while minimizing workflow burden and unnecessary testing and is more efficacious than both sequential and tandem screening strategies.
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January 2021

The Origin, Succession, and Predicted Metabolism of Bacterial Communities Associated with Leaf Decomposition.

mBio 2019 09 3;10(5). Epub 2019 Sep 3.

Department of Ecology & Evolution, University of Chicago, Chicago, Illinois, USA.

Intraspecific variation in plant nutrient and defensive traits can regulate ecosystem-level processes, such as decomposition and transformation of plant carbon and nutrients. Understanding the regulatory mechanisms of ecosystem functions at local scales may facilitate predictions of the resistance and resilience of these functions to change. We evaluated how riverine bacterial community assembly and predicted gene content corresponded to decomposition rates of green leaf inputs from red alder trees into rivers of Washington State, USA. Previously, we documented accelerated decomposition rates for leaves originating from trees growing adjacent to the site of decomposition versus more distant locales, suggesting that microbes have a "home-field advantage" in decomposing local leaves. Here, we identified repeatable stages of bacterial succession, each defined by dominant taxa with predicted gene content associated with metabolic pathways relevant to the leaf characteristics and course of decomposition. "Home" leaves contained bacterial communities with distinct functional capacities to degrade aromatic compounds. Given known spatial variation of alder aromatics, this finding helps explain locally accelerated decomposition. Bacterial decomposer communities adjust to intraspecific variation in leaves at spatial scales of less than a kilometer, providing a mechanism for rapid response to changes in resources such as range shifts among plant genotypes. Such rapid responses among bacterial communities in turn may maintain high rates of carbon and nutrient cycling through aquatic ecosystems. Community ecologists have traditionally treated individuals within a species as uniform, with individual-level biodiversity rarely considered as a regulator of community and ecosystem function. In our study system, we have documented clear evidence of within-species variation causing local ecosystem adaptation to fluxes across ecosystem boundaries. In this striking pattern of a "home-field advantage," leaves from individual trees tend to decompose most rapidly when immediately adjacent to their parent tree. Here, we merge community ecology experiments with microbiome approaches to describe how bacterial communities adjust to within-species variation in leaves over spatial scales of less than a kilometer. The results show that bacterial community compositional changes facilitate rapid ecosystem responses to environmental change, effectively maintaining high rates of carbon and nutrient cycling through ecosystems.
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September 2019

Reconciling empirical interactions and species coexistence.

Ecol Lett 2019 Jun 22;22(6):1028-1037. Epub 2019 Mar 22.

Department of Ecology and Evolution, University of Chicago, 1101 E. 57th, Chicago, IL, 60637, USA.

Coexistence in ecological communities is governed largely by the nature and intensity of species interactions. Countless studies have proposed methods to infer these interactions from empirical data, yet models parameterised using such data often fail to recover observed coexistence patterns. Here, we propose a method to reconcile empirical parameterisations of community dynamics with species-abundance data, ensuring that the predicted equilibrium is consistent with the observed abundance distribution. To illustrate the approach, we explore two case studies: an experimental freshwater algal community and a long-term time series of displacement in an intertidal community. We demonstrate how our method helps recover observed coexistence patterns, capture the core dynamics of the system, and, in the latter case, predict the impacts of experimental extinctions. Collectively, these results demonstrate an intuitive approach for reconciling observed and empirical data, improving our ability to explore the links between species interactions and coexistence in natural systems.
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June 2019

Impact of sequential implementation of multimodal perioperative care pathways on colorectal surgical outcomes

Can J Surg 2019 02;62(1):25-32

From the Faculty of Medicine, University of British Columbia, Vancouver, BC (D’Souza, Choi, Wallace); the Interior Health Authority Quality, Risk, and Accreditation, Royal Inland Hospital, Kamloops, BC (Wootton, Wallace); and the Division of General Surgery, Department of Surgery, University of British Columbia, Vancouver, BC (Wallace).

Background: Standardized care protocols offer the potential to reduce postoperative complication rates. The purpose of this study was to determine whether there was an additive benefit associated with the sequential implementation of the evidence-based surgical site infection bundle (SSIB) and enhanced recovery after surgery (ERAS) protocols for patients undergoing colorectal surgery in a community hospital.

Methods: Patients at a single institution who underwent elective colorectal surgery between Apr. 1, 2011, and Dec. 31, 2015, were identified by means of American College of Surgeons National Surgical Quality Improvement Program data. Patients were stratified into 3 groups according to the protocol implementation dates: pre-SSIB/pre-ERAS (control), post-SSIB/pre-ERAS and post-SSIB/post-ERAS. Primary outcomes assessed were length of stay and wound complication rates. We used inverse proportional weighting to control for possible differences between the groups.

Results: There were 368 patients included: 94 in the control group, 95 in the post-SSIB/pre-ERAS group and 179 in the post-SSIB/post-ERAS group. In the adjusted analyses, mean length of stay (control group 7.6 d, post-SSIB/post-ERAS group 5.5 d, p = 0.04) and overall wound complication rates (14.7% and 6.5%, respectively, p = 0.049) were reduced after sequential implementation of the protocols.

Conclusion: Sequential implementation of quality-improvement initiatives yielded additive benefit for patients undergoing colorectal surgery in a community hospital, with a decrease in length of stay and wound complication rates. The amount of improvement attributable to either initiative is difficult to define as they were implemented sequentially. The improved outcomes were realized after the introduction of the ERAS protocol in adjusted analyses.
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February 2019