Butyrate-Producing Bacteria and Insulin Homeostasis: The Microbiome and Insulin Longitudinal Evaluation Study (MILES).

Gut microbiome studies have documented depletion of butyrate-producing taxa in type 2 diabetes. We analyzed associations between butyrate-producing taxa and detailed measures of insulin homeostasis, whose dysfunction underlies diabetes in 224 non-Hispanic Whites and 129 African Americans, all of whom completed an oral glucose tolerance test. Stool microbiome was assessed by whole-metagenome shotgun sequencing with taxonomic profiling.

Cytotoxic T lymphocyte antigen-4 regulates development of xenogenic graft versus host disease in mice via modulation of host immune responses induced by changes in human T cell engraftment and gene expression.

Graft versus host disease (GvHD) is a major clinical problem with a significant unmet medical need. We examined the role of cytotoxic T lymphocyte antigen-4 (CTLA-4) in a xenogenic GvHD (xeno-GvHD) model induced by injection of human peripheral mononuclear cells (hPBMC) into irradiated non-obese diabetic (NOD) SCID gamma (NSG) mice. Targeting the CTLA-4 pathway by treatment with CTLA-4 immunoglobulin (Ig) prevented xeno-GvHD, while anti-CTLA-4 antibody treatment exacerbated the lethality and morbidity associated with GvHD.

Distinct roles of histamine H1- and H2-receptor signaling pathways in inflammation-associated colonic tumorigenesis.

Inflammatory bowel disease (IBD) is a well-known risk factor for the development of colorectal cancer. Prior studies have demonstrated that microbial histamine can ameliorate intestinal inflammation in mice. We tested the hypothesis whether microbe-derived luminal histamine suppresses inflammation-associated colon cancer in Apc mice.

Gut Microbe-Mediated Suppression of Inflammation-Associated Colon Carcinogenesis by Luminal Histamine Production.

Microbiome-mediated suppression of carcinogenesis may open new avenues for identification of therapeutic targets and prevention strategies in oncology. Histidine decarboxylase (HDC) deficiency has been shown to promote inflammation-associated colorectal cancer by accumulation of CD11bGr-1 immature myeloid cells, indicating a potential antitumorigenic effect of histamine. Here, we demonstrate that administration of hdcLactobacillus reuteri in the gut resulted in luminal hdc gene expression and histamine production in the intestines of Hdc mice.

FolC2-mediated folate metabolism contributes to suppression of inflammation by probiotic Lactobacillus reuteri.

Bacterial-derived compounds from the intestinal microbiome modulate host mucosal immunity. Identification and mechanistic studies of these compounds provide insights into host-microbial mutualism. Specific Lactobacillus reuteri strains suppress production of the proinflammatory cytokine, tumor necrosis factor (TNF), and are protective in a mouse model of colitis.

Histamine H2 Receptor-Mediated Suppression of Intestinal Inflammation by Probiotic Lactobacillus reuteri.

Unlabelled: Probiotics and commensal intestinal microbes suppress mammalian cytokine production and intestinal inflammation in various experimental model systems. Limited information exists regarding potential mechanisms of probiotic-mediated immunomodulation in vivo. In this report, we demonstrate that specific probiotic strains of Lactobacillus reuteri suppress intestinal inflammation in a trinitrobenzene sulfonic acid (TNBS)-induced mouse colitis model.

Compositional and functional features of the gastrointestinal microbiome and their effects on human health.

The human gastrointestinal tract contains distinct microbial communities that differ in composition and function based on their location, as well as age, sex, race/ethnicity, and diet of their host. We describe the bacterial taxa present in different locations of the GI tract, and their specific metabolic features. The distinct features of these specific microbial communities might affect human health and disease.

Characterization of two long-chain fatty acid CoA ligases in the Gram-positive bacterium Geobacillus thermodenitrificans NG80-2.

The functions of two long-chain fatty acid CoA ligase genes (facl) in crude oil-degrading Geobacillus thermodenitrificans NG80-2 were characterized. Facl1 and Facl2 encoded by GTNG_0892 and GTNG_1447 were expressed in Escherichia coli and purified as His-tagged fusion proteins. Both enzymes utilized a broad range of fatty acids ranging from acetic acid (C(2)) to melissic acid (C(30)).

Rapid identification of heterozygous mutations in Drosophila melanogaster using genomic capture sequencing.

One of the key advantages of using Drosophila melanogaster as a genetic model organism is the ability to conduct saturation mutagenesis screens to identify genes and pathways underlying a given phenotype. Despite the large number of genetic tools developed to facilitate downstream cloning of mutations obtained from such screens, the current procedure remains labor intensive, time consuming, and costly. To address this issue, we designed an efficient strategy for rapid identification of heterozygous mutations in the fly genome by combining rough genetic mapping, targeted DNA capture, and second generation sequencing technology.

A recalibrated molecular clock and independent origins for the cholera pandemic clones.

Cholera, caused by Vibrio cholerae, erupted globally from South Asia in 7 pandemics, but there were also local outbreaks between the 6(th) (1899-1923) and 7(th) (1961-present) pandemics. All the above are serotype O1, whereas environmental or invertebrate isolates are antigenically diverse. The pre 7th pandemic isolates mentioned above, and other minor pathogenic clones, are related to the 7(th) pandemic clone, while the 6(th) pandemic clone is in the same lineage but more distantly related, and non-pathogenic isolates show no clonal structure.

The nos gene cluster from gram-positive bacterium Geobacillus thermodenitrificans NG80-2 and functional characterization of the recombinant NosZ.

The nos gene cluster encoding the activity of nitrous oxide reductase (N2OR) for the final step of the denitrification pathway has been well studied in gram-negative bacteria. Our previous study on the genome of Geobacillus thermodenitrificans NG80-2 revealed the presence of the nos gene cluster in this gram-positive bacterium. In this follow-up study, the nos gene cluster of G.

Genome and proteome of long-chain alkane degrading Geobacillus thermodenitrificans NG80-2 isolated from a deep-subsurface oil reservoir.

The complete genome sequence of Geobacillus thermodenitrificans NG80-2, a thermophilic bacillus isolated from a deep oil reservoir in Northern China, consists of a 3,550,319-bp chromosome and a 57,693-bp plasmid. The genome reveals that NG80-2 is well equipped for adaptation into a wide variety of environmental niches, including oil reservoirs, by possessing genes for utilization of a broad range of energy sources, genes encoding various transporters for efficient nutrient uptake and detoxification, and genes for a flexible respiration system including an aerobic branch comprising five terminal oxidases and an anaerobic branch comprising a complete denitrification pathway for quick response to dissolved oxygen fluctuation. The identification of a nitrous oxide reductase gene has not been previously described in Gram-positive bacteria.

[Molecular characterization of O-antigen gene cluster of Escherichia coli O23 reference strain and identification of UDP-N-acetylglucosamine 4-epimerase].

Lipopolysaccharide (LPS) is one of the major components of the outer membrane of gram-negative bacteria. It is an amphipathic molecule composing of lipid A, a core oligosaccharide and an O-specific antigen. O-antigen, which is a repeat unit polysaccharide, is a major contribution to the antigenic variability of the bacterial cell surface.