WikiBiomeThe human microbiome encyclopediaRanked matches across titles, topics, categories, and article introductions.
The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor that functions as a master sensor at the intersection of gut microbial metabolism, environmental chemical exposure, and immune regulation. It is expressed broadly across immune cells, intesti…
This page serves as a cross-reference point for the existing ahr concept page, which provides comprehensive coverage of AhR signaling, microbiome-derived ligands, and immune regulation. The aryl hydrocarbon receptor is a ligand-activated transcription factor that integr…
Bacteroides thetaiotaomicron is one of the most abundant and metabolically versatile commensals of the human gut, routinely cited as a model organism for studying host-microbe symbiosis. Its genome was one of the first human gut bacterial genomes fully sequenced, and su…
Alphabetical definitions of specialist terms used throughout this wiki. Where a full concept page exists, the term links to it. --- AhR (aryl hydrocarbon receptor) -- A ligand-activated transcription factor that senses microbial metabolites (especially indoles from tryp…
Indole is a microbial metabolite produced from tryptophan by bacterial tryptophanase (TnaA). It is one of the most abundant microbial signals in the gut (concentrations reach 250–1,100 µM in the colon) and the primary endogenous ligand for the aryl hydrocarbon receptor …
Microbial tryptophan metabolites produced by gut bacteria through the third branch of tryptophan metabolism -- the indole pathway. Unlike the host-dominated kynurenine pathway (~95% of Trp) and the serotonin pathway (~1-2%), the indole pathway is exclusively microbial a…
Interleukin-22 (IL-22) is an immune signaling protein that helps coordinate host responses at epithelial surfaces. In the gut evidence represented by WikiBiome, group 3 innate lymphoid cells (ILC3s) are a prominent source, while Th17-associated responses can also includ…
Kynurenine is the primary metabolite of the kynurenine pathway, which handles ~95% of tryptophan catabolism in the body. While serotonin gets more attention, the kynurenine pathway is quantitatively dominant -- and its downstream metabolites span the range from neuropro…
Necrotizing enterocolitis (NEC) is the most common and lethal gastrointestinal emergency in premature infants, affecting 5-12% of very low birth weight neonates (<1500 g) with mortality rates of 20-30%. Characterized by intestinal inflammation, necrosis, and perforation…
Tryptophan (Trp) is an essential amino acid that the human body cannot synthesize and must obtain from diet. It occupies a uniquely important position at the intersection of neuroscience, immunology, and microbial ecology because it is the sole precursor to serotonin, a…
Tryptophan (Trp) is an essential amino acid metabolized via three competing pathways: the kynurenine pathway, the serotonin pathway, and the microbial indole pathway. The balance among these pathways is profoundly influenced by the gut microbiome, inflammation, and meta…