BilR is a gut microbial enzyme that reduces bilirubin to urobilinogen.

Metabolism of haem by-products such as bilirubin by humans and their gut microbiota is essential to human health, as excess serum bilirubin can cause jaundice and even neurological damage. The bacterial enzymes that reduce bilirubin to urobilinogen, a key step in this pathway, have remained unidentified. Here we used biochemical analyses and comparative genomics to identify BilR as a gut-microbiota-derived bilirubin reductase that reduces bilirubin to urobilinogen.

Discovery of the gut microbial enzyme responsible for bilirubin reduction to urobilinogen.

The degradation of heme and the interplay of its catabolic derivative, bilirubin, between humans and their gut microbiota is an essential facet of human health. However, the hypothesized bacterial enzyme that reduces bilirubin to urobilinogen, a key step that produces the excretable waste products of this pathway, has remained unidentified. In this study, we used a combination of biochemical analyses and comparative genomics to identify a novel enzyme, BilR, that can reduce bilirubin to urobilinogen.

Gut Microbiome-Wide Search for Bacterial Azoreductases Reveals Potentially Uncharacterized Azoreductases Encoded in the Human Gut Microbiome.

The human gut is home to trillions of microorganisms that are responsible for the modification of many orally administered drugs, leading to a wide range of therapeutic outcomes. Prodrugs bearing an azo bond are designed to treat inflammatory bowel disease and colorectal cancer via microbial azo reduction, allowing for topical application of therapeutic moieties to the diseased tissue in the intestines. Despite the inextricable link between microbial azo reduction and the efficacy of azo prodrugs, the prevalence, abundance, and distribution of azoreductases have not been systematically examined across the gut microbiome.

The Capacity to Produce Hydrogen Sulfide (HS) via Cysteine Degradation Is Ubiquitous in the Human Gut Microbiome.

As one of the three mammalian gasotransmitters, hydrogen sulfide (HS) plays a major role in maintaining physiological homeostasis. Endogenously produced HS plays numerous beneficial roles including mediating vasodilation and conferring neuroprotection. Due to its high membrane permeability, exogenously produced HS originating from the gut microbiota can also influence human physiology and is implicated in reducing intestinal mucosal integrity and potentiating genotoxicity and is therefore a potential target for therapeutic interventions.

Interactive exploratory data analysis of Integrative Human Microbiome Project data using Metaviz.

The rich data produced by the second phase of the Human Microbiome Project (iHMP) offers a unique opportunity to test hypotheses that interactions between microbial communities and a human host might impact an individual's health or disease status. In this work we describe infrastructure that integrates Metaviz, an interactive microbiome data analysis and visualization tool, with the iHMP Data Coordination Center web portal and the R/Bioconductor package. We describe integrative statistical and visual analyses of two datasets from iHMP using Metaviz along with the R/Bioconductor package for statistical analysis of differential abundance analysis.

A framework for assessing 16S rRNA marker-gene survey data analysis methods using mixtures.

Background: There are a variety of bioinformatic pipelines and downstream analysis methods for analyzing 16S rRNA marker-gene surveys. However, appropriate assessment datasets and metrics are needed as there is limited guidance to decide between available analysis methods. Mixtures of environmental samples are useful for assessing analysis methods as one can evaluate methods based on calculated expected values using unmixed sample measurements and the mixture design.

Lyme Disease Manifestations in the Foot and Ankle: A Retrospective Case Series.

Lyme disease is the result of Borrelia burgdorferi bacterial infection after exposure from a tick bite. A pathognomonic finding in early-stage Lyme disease is an expanding, red macular ring known as erythema migrans. Lyme arthritis is a late-stage manifestation of this disease, affecting the large, weightbearing joints with intermittent pain and swelling.