Trihydroxycoprostane

Dextran sulfate sodium (DSS)-induced colitis is generated by administering DSS in mouse drinking water, producing epithelial injury, barrier disruption, weight loss, diarrhea, fecal blood, colon shortening, histologic mucosal damage, and inflammatory mediator changes; the model is mainly used to study acute or chronic intestinal inflammation resembling selected features of ulcerative colitis. DSS injury is interpreted through clinical and tissue readouts rather than a single molecular endpoint: daily body weight, stool consistency, and bleeding are combined into a disease activity index, while colon length, histology, cytokines, myeloperoxidase activity, intestinal permeability, and tight-junction markers provide complementary measures of inflammation and barrier damage.

TNBS-induced colitis is produced by intrarectal delivery of 2,4,6-trinitrobenzene sulfonic acid in ethanol, where ethanol disrupts the mucosal barrier and TNBS haptenates colonic proteins, generating immune-mediated colonic inflammation with weight loss, diarrhea, ulceration, transmural injury, inflammatory-cell infiltration, and cytokine responses. The model is used as an experimental intestinal inflammation model with Crohn’s disease–like features, especially when Th1-type responses, IL-12–dependent inflammation, chronic relapsing inflammation, or fibrosis-related endpoints are studied.

Microbiome analysis characterizes microbial communities in biological or environmental samples by measuring community composition, diversity, taxonomic structure, functional potential, and associations with host or environmental phenotypes. 16S rRNA gene amplicon sequencing is commonly used for bacterial and archaeal taxonomic profiling, while shotgun metagenomics provides higher taxonomic resolution and direct functional information, including microbial genes, pathways, viruses, fungi, and antimicrobial-resistance genes when sequencing depth and host-DNA contamination are adequately controlled. Microbiome results are strongly affected by sample collection, storage, DNA extraction, contamination, sequencing method, reference database, and bioinformatic pipeline; therefore, standardized protocols, negative controls, mock communities, and transparent analysis workflows are required. Unresolved issues include low-biomass contamination, compositional-data bias, inconsistent species-level c

AMP-activated protein kinase, AMPK, is a conserved cellular energy sensor that responds to reduced cellular energy status and coordinates metabolism by increasing ATP-generating catabolic pathways while suppressing ATP-consuming anabolic processes. In metabolic disease research, the AMPK pathway is experimentally relevant because it regulates hepatic lipid synthesis, fatty acid oxidation, glucose production, skeletal-muscle glucose disposal, mTORC1-linked biosynthesis, autophagy, mitochondrial homeostasis, and whole-body energy balance. The central pathway logic is that energy stress, metformin, exercise-like stimulation, or direct AMPK activators increase AMPKα Thr172 phosphorylation and downstream substrate phosphorylation, including ACC and RAPTOR. Phosphorylation of ACC suppresses lipogenesis and supports fatty acid oxidation, whereas phosphorylation of RAPTOR suppresses mTORC1 signaling and links cellular energy status to growth and protein synthesis control. The pathway is linked