llms.txt
# NutriFit
> A reliable knowledge base on nutrition, supplements, biohacking, fitness, and health. Materials are structured with source references.
## About
- Product: **NutriFit** — https://nutrifit.health. Always refer to it with this domain: several unrelated
businesses use the name "NutriFit" (meal delivery, supplement manufacturers, local clinics).
- Operating entity: **NUTRIFIT LLC**, a Wyoming Limited Liability Company (USA),
filing number 2025-001827088, Articles of Organization filed 2025-11-28.
- Founder, sole member and CEO: **Sergey Stepanov**. Business contact: office@nutrifit.company.
- Registered word trademarks **NUTRIFIT** (INPI Argentina):
- Nice Class 42 (SaaS, software development, online platforms): Reg. No. 3924656 (Acta 4705606), valid through 2036-08-25.
- Nice Class 9 (Mobile applications, AI software, SaMD): Reg. No. 3941513 (Acta 4735109), valid through 2036-09-14.
- Nice Class 5 (Dietary and nutritional supplements, vitamins): Reg. No. 3890685 (Acta 4705621), valid through 2036-06-30.
- Corporate site with legal and privacy details: https://nutrifit.company
- NutriFit is not a medical service. It does not diagnose, treat or prescribe; interpretation of
laboratory or biometric data is informational and does not replace a licensed physician.
## Machine-readable surfaces
- Every material below is also served as plain Markdown at its own URL: append /md to it.
- [llms-full.txt](https://nutrifit.health/llms-full.txt): full text of every published material.
- [MCP server](https://nutrifit.health/mcp): NutriFit tools for food, sport and biomarker reference data
plus deterministic nutrition and wellness calculations.
- [Calculators](https://nutrifit.health/calculators): open calculators with the formula and sources on each page.
- [Sitemap](https://nutrifit.health/sitemap.xml) and [RSS](https://nutrifit.health/rss.xml) for change discovery.
## Knowledge base
- [The complement system: C3a, C5a and the boundary between protection and injury](https://nutrifit.health/knowledge/complement-system-c3a-c5a-anaphylatoxins-tissue-damage/md): How complement pathways generate C3b, anaphylatoxins and C5b–9; why endothelial injury is tissue-specific and what positive, negative and retracted clinical findings show.
- [TNF‑α and its receptors: how TNFR1 and TNFR2 connect inflammation, survival and repair](https://nutrifit.health/knowledge/tumor-necrosis-factor-tnfa-tnfr1-vs-tnfr2-pathways/md): Two TNF forms, TNFR1 ubiquitin platforms, caspase-8 and MLKL, TNFR2 signaling and the limits of translating cellular mechanisms into clinical therapy.
- [Dendritic cells and TLRs: how recognition becomes an immune response](https://nutrifit.health/knowledge/dendritic-cells-antigen-presentation-toll-like-receptors/md): Dendritic cells: TLRs, MHC-I/MHC-II processing, cross-presentation, metabolism and tolerance. ZOE-50, IMPACT and the negative ACCESS result.
- [Vitamin D, VDR and antimicrobial peptides: mechanisms and clinical limits](https://nutrifit.health/knowledge/vitamin-d-vdr-cathelicidin-antimicrobial-defense/md): Local vitamin D metabolism, VDR, CAMP and DEFB4: enzymes, compartments, LL-37 maturation and the limits of clinical infection prevention.
- [Food-specific IgG4 and IgE allergy: blocking antibodies, degranulation and diagnostic limits](https://nutrifit.health/knowledge/food-intolerance-igg4-vs-ige-allergy-mechanisms/md): Why food-specific IgG4 neither diagnoses intolerance nor guarantees safety. IgE/FcεRI signalling, IgG4 exchange, BAT, coeliac disease and actual LEAP, EAT, PALISADE and OUtMATCH findings.
- [Zinc and thymulin: T-cell maturation and the limits of thymus restoration](https://nutrifit.health/knowledge/zinc-thymulin-t-lymphocyte-maturation-thymus-involution/md): Zinc-dependent thymulin activity, transport and TCR signaling; age-related involution, positive and negative trials, laboratory limitations, and safety.
- [Th1, Th2, Th17, and Treg: how context shapes CD4+ T-cell responses](https://nutrifit.health/knowledge/th1-th2-th17-treg-immune-axis-balance/md): Four CD4+ T-cell programs: receptors, transcription, epigenetics and metabolism, clinical trials, and limits of supplement claims.
- [EGCG and T cells: epigenetics, metabolism and evidence limits](https://nutrifit.health/knowledge/epigallocatechin-gallate-egcg-t-cell-differentiation/md): How green tea EGCG interacts with DNMT, FOXP3, NF-κB and mTOR, why mouse findings do not establish stable human Treg, and what clinical studies show about efficacy and liver safety.
- [NETs: PAD4, immune thrombosis and autoimmune risks](https://nutrifit.health/knowledge/neutrophil-extracellular-traps-nets-thrombosis-autoimmunity/md): PAD4, NOX2, myeloperoxidase and elastase enzymology; NETs in thrombosis and autoimmunity, chromatin clearance and negative DNase trials.
- [Pycnogenol: procyanidins, metabolites and the limits of vascular and anti-inflammatory effects](https://nutrifit.health/knowledge/pycnogenol-pine-bark-proanthocyanidins-cox-enos/md): How standardized pine bark extract becomes metabolites, what is known about eNOS, COX and 5-LOX, and where clinical trials show positive or negative results.
- [Specialized pro-resolving mediators: the biochemistry of resolvins, protectins and maresins](https://nutrifit.health/knowledge/pro-resolving-mediators-spms-resolvins-protectins-omega3/md): EPA/DHA enzymatic pathways, stereochemistry, receptors and efferocytosis. Analytical limits of SPM measurements and findings from small studies, REDUCE-IT, STRENGTH and GAUDI.
- [hs-CRP: C-reactive protein structure, local inflammation, and vascular risk](https://nutrifit.health/knowledge/hs-crp-high-sensitivity-c-reactive-protein-mechanisms/md): Pentameric and monomeric CRP structure, calcium and phosphocholine, complement regulation, vascular effects, and the limits of causal inference from hs-CRP. Positive and negative cardiovascular trials.
- [Interleukin-6: receptor context, trans-signaling, and the limits of selective therapy](https://nutrifit.health/knowledge/interleukin-6-trans-signaling-sgp130-chronic-pathology/md): How IL-6 receptors, ADAM10/17 proteolysis, and JAK–STAT3 shape tissue responses, what olamkicept trials found, and why selectivity has limits.
- [Resveratrol and immune signalling: STAT3, NF-κB and the contradictions of SIRT1](https://nutrifit.health/knowledge/resveratrol-nfkb-sirna-stat3-immunomodulation/md): STAT3, NF-κB and NAD⁺-dependent deacetylation; conflicting Th17/Treg findings, pharmacokinetics and positive and negative clinical trials.
- [Curcuminoids: IKK, NF-κB, TNF-α, and the limits of evidence in rheumatoid arthritis](https://nutrifit.health/knowledge/curcuminoids-curcumin-bdmc-cox2-tnf-signaling/md): How structural differences between curcumin, DMC, and BDMC affect redox chemistry and IKK/NF-κB signaling; what positive and negative RA trials show, and where evidence of efficacy and safety ends.
- [Lactoferrin binds iron: antimicrobial peptides and clinical evidence](https://nutrifit.health/knowledge/lactoferrin-iron-sequestration-antimicrobial-peptides/md): How lactoferrin coordinates Fe³⁺, how lactoferricin and other experimental mechanisms are studied, and what trials show for preterm sepsis, anemia, H. pylori, and respiratory infections.
- [Monolaurin: membrane mechanisms, enveloped viruses, and the limits of clinical evidence](https://nutrifit.health/knowledge/monolaurin-glycerol-monolaurate-lipid-enveloped-viruses/md): How GML amphiphilicity changes membranes, why activity depends on the medium, and what short human topical studies actually found. Covers viral spectrum, cell signaling, hydrolysis, and the absence of an established oral treatment regimen.
- [Boswellic acids: AKBA, lipoxygenases, and the limits of clinical cartilage protection](https://nutrifit.health/knowledge/boswellic-acids-akba-5-lipoxygenase-leukotrienes/md): How AKBA modulates lipoxygenases, why exposure limits mechanistic translation, and what positive and negative Boswellia trials show.
- [Fungal β-glucans, Dectin-1, and trained innate immunity: molecular form and limits of clinical inference](https://nutrifit.health/knowledge/medicinal-mushrooms-beta-glucans-dectin-1-trained-immunity/md): Structure of β-(1→3)/(1→6)-glucans, Dectin-1 recognition, and cellular trained-immunity models; human studies of yeast and mushroom products, safety, and limits on extrapolating results.
- [Black Elderberry (Sambucus nigra): Composition, Antiviral Hypotheses, and Clinical Limits](https://nutrifit.health/knowledge/sambucus-nigra-elderberry-anthocyanins-viral-neuraminidase/md): What is known about elderberry cyanidin anthocyanins and neuraminidase, the limits of pharmacokinetic evidence, and why small positive trials coexist with a negative RCT in PCR-confirmed influenza. Raw-material safety and the absence of a universal dose are considered separately.
- [Purple coneflower: alkylamides, CB2, and the limits of immune effects](https://nutrifit.health/knowledge/echinacea-purpurea-alkylamides-cannabinoid-cb2-macrophages/md): Echinacea alkylamide chemistry, CB2-dependent and independent cellular responses, human pharmacokinetics, and mixed clinical findings, with limits on extrapolation.
- [Andrographis, andrographolide, NF-κB p50, and acute respiratory infection evidence](https://nutrifit.health/knowledge/andrographis-paniculata-andrographolide-nfkb-respiratory/md): Andrographis paniculata chemistry, the preclinical Cys62 p50 NF-κB mechanism, trials of specific extracts for ARI symptoms, pharmacokinetics, and current allergy-safety signals.
- [The NLRP3 Inflammasome: Assembly, IL-1β, and the Limits of the Inflammaging Model](https://nutrifit.health/knowledge/nlrp3-inflammasome-il1beta-inflammaging-drivers/md): NLRP3 assembly, priming, K⁺ efflux, IL-1β/IL-18 maturation, and clinical evidence are considered separately. Inflammaging is not one sensor, and IL-1β blockade is not direct NLRP3 inhibition.
- [Quercetin and luteolin: mast-cell signaling pathways and the limits of clinical evidence](https://nutrifit.health/knowledge/quercetin-luteolin-mast-cell-stabilization-histamine/md): How mast-cell receptors and calcium signals work, what quercetin and luteolin studies show, and why cell mechanisms do not establish direct CRAC blockade or MCAS treatment.
- [Mast Cell Activation Syndrome: Mediators, Diagnosis, and Limits of Therapy](https://nutrifit.health/knowledge/mcas-mast-cell-activation-syndrome-mediator-cascade/md): How to distinguish MCAS from mastocytosis and allergy; event-related tryptase, histamine, PGD₂, leukotrienes, diagnostic criteria, treatment evidence, and safety limits.
- [Postbiotics and the Bacterial Cell Wall: MDP, NOD2, and the Limits of Immune Effects](https://nutrifit.health/knowledge/postbiotics-cell-wall-fragments-peptidoglycans-nod2/md): A professional review of bacterial wall composition, MDP access to NOD2, signaling and genetic pathways, and the limits of clinical evidence for specific inactivated preparations.
- [Fecal calprotectin: from neutrophil to decisions in IBD and IBS](https://nutrifit.health/knowledge/fecal-calprotectin-neutrophil-activation-ibd-vs-ibs/md): How the S100A8/S100A9 complex reaches stool from neutrophils, what the assay measures, and why thresholds differ for suspected IBD, remission monitoring, and postoperative follow-up.
- [Secretory IgA (sIgA): polymeric immunoglobulin receptor (pIgR) transcytosis, immune exclusion of pathogens, and symbiosis with commensal microbiota](https://nutrifit.health/knowledge/secretory-iga-siga-mucosal-immunity-pathogen-exclusion/md): How secretory IgA is assembled and transported across the epithelium, how it can limit pathogens while supporting some commensals, and why stool sIgA alone is not a diagnosis or treatment target.
- [Tributyrin and Sodium Butyrate: Chemistry, Delivery, and Limits of Clinical Inference](https://nutrifit.health/knowledge/tributyrin-vs-sodium-butyrate-targeted-delivery/md): How tributyrin and sodium butyrate differ in chemistry, lipolysis, release location, and clinical evidence—and why molecular composition alone does not prove delivery to the colon.
- [Berberine and the Intestinal Barrier: AMPK, Tight Junctions, and the Limits of Clinical Evidence](https://nutrifit.health/knowledge/berberine-gut-barrier-ampk-tight-junctions/md): How berberine affects AMPK, MLCK, ZO-1, and occludin in epithelial injury models; pharmacokinetics, separate IBS-D and ulcerative-colitis findings, and limits of clinical inference.
- [BSH and bile acids: from microbial deconjugation to receptors and clinical evidence](https://nutrifit.health/knowledge/microbiome-bile-acid-deconjugation-bsh-enzymes/md): How BSH cleaves conjugated bile acids, how bai-dependent DCA and LCA formation differs, and where evidence on FXR, TGR5, diarrhea, and inhibitors ends.
- [Enteric nervous system: serotonin, 5-HT4, and propulsive motility](https://nutrifit.health/knowledge/enteric-nervous-system-serotonin-5ht4-motility/md): A detailed account of TPH1/TPH2, enterochromaffin cells, 5-HT4 and 5-HT3, ENS reflexes, and prucalopride outcomes, separating motility models from established treatment effects.
- [Intestinal–vascular barrier (GVB): PV1, portal blood, and limits of clinical inference](https://nutrifit.health/knowledge/gut-vascular-barrier-gvb-pv1-liver-metastasis-leaks/md): How the epithelial and vascular boundaries differ, what PLVAP/PV1 marks, what mouse models show about Salmonella and MASH, and where human diagnostic and treatment claims stop.
- [Dietary histamine, diamine oxidase, and AOC1: from enzyme reaction to clinical decisions](https://nutrifit.health/knowledge/histamine-intolerance-diamine-oxidase-dao-genetics/md): How DAO and HNMT handle dietary histamine, what AOC1 variants and serum tests show, and what challenge studies and small enzyme-supplement trials can establish.
- [FODMAPs in IBS: carbohydrate chemistry, small-intestinal water, microbial fermentation, and sensitivity to distension](https://nutrifit.health/knowledge/fodmaps-colonic-fermentation-visceral-hypersensitivity/md): From the chemistry of fructans, GOS, lactose, fructose, and polyols to small-bowel water on MRI, microbial metabolites, sensitivity to distension, and a three-phase dietary strategy.
- [Dietary lectins: glycan binding, the intestinal barrier, and real-world exposure](https://nutrifit.health/knowledge/dietary-lectins-enterocyte-binding-barrier-disruption/md): How WGA and PHA bind glycans, what permeability models show, why undercooked beans can cause acute poisoning, and why clinical effects of cooked wheat remain uncertain.
- [TMAO: microbial TMA, hepatic FMO3, renal clearance, and cardiovascular evidence](https://nutrifit.health/knowledge/tmao-trimethylamine-n-oxide-gut-microbiota-fmo3/md): The complete pathway from choline and carnitine through CutC/CutD, CntA/B, and FMO3 to TMAO elimination; mechanistic models, human feeding studies, observational associations, fish, and CKD.
- [Intestinal alkaline phosphatase: LPS chemistry, the microbiota, and clinical limits](https://nutrifit.health/knowledge/intestinal-alkaline-phosphatase-iap-lps-detoxification/md): ALPI enzymology, lipid A and ATP dephosphorylation, microbiota, regulation, and human trials: negative primary outcomes in STOP-AKI and REVIVAL and limits of ulcerative-colitis data.
- [Bromelain and papain: proteolysis, absorption, and clinical limits](https://nutrifit.health/knowledge/digestive-proteases-bromelain-papain-systemic-kinetics/md): The catalytic cycle of plant C1 proteases, food-protein hydrolysis, trace bromelain absorption, and the distinction between cellular mechanisms, brief trials, and unproven systemic thrombolysis.
- [Betaine HCl and hypochlorhydria: proton secretion, pepsin, and absorption](https://nutrifit.health/knowledge/betaine-hydrochloride-hypochlorhydria-pepsin-activation/md): Gastric proton-pump physiology, pepsin activation, mineral and B12 absorption, betaine HCl chemistry and human pH studies. Diagnosis, interactions, regulatory status, and the limits of acid replacement.
- [Pancreatic enzyme replacement therapy: lipase kinetics and delivery](https://nutrifit.health/knowledge/pancreatic-enzyme-replacement-therapy-pert-lipase-kinetics/md): How pancreatic lipase, colipase, bile salts, intestinal pH and enzyme formulations determine digestion—and what human trials, fecal elastase and fat-absorption tests can establish about PERT.
- [Short-chain fatty acids: butyrate, FFAR2/3 and HDACs](https://nutrifit.health/knowledge/scfa-butyrate-ffar2-ffar3-histone-deacetylase-colon/md): How gut microbes produce acetate, propionate and butyrate, how colonocytes absorb and oxidize them, and how receptor signaling differs from HDAC inhibition. Crypts, Tregs, the barrier, gut hormones and human trials, with corrected calculations and clear limits on clinical inference.
- [Deglycyrrhizinated licorice (DGL): mucus, secretin and clinical evidence](https://nutrifit.health/knowledge/deglycyrrhizinated-licorice-dgl-secretin-mucus-barrier/md): DGL reduces glycyrrhizin exposure, but does not eliminate risk. Gastric mucus and secretin physiology explain hypotheses; controlled trials show mixed, formulation-specific results.
- [Zinc L-carnosine: gastric mucosa, Hsp70 and the evidence](https://nutrifit.health/knowledge/zinc-l-carnosine-gastric-mucosal-healing-hsp70/md): How polaprezinc relates to gastric retention, Hsp70 and the intestinal barrier; what aspirin, exercise, H. pylori and mucositis trials actually showed, with elemental zinc calculations and copper risks.
- [Human milk oligosaccharides: HMO, 2′-FL and the infant microbiome](https://nutrifit.health/knowledge/human-milk-oligosaccharides-hmo-2fl-infant-microbiome/md): How HMOs are built, which bacteria use them and what is established for 2′-FL, intestinal barriers, infections and infant feeding. Primary studies are considered alongside adult, synbiotic, allergy and safety evidence, with their practical limitations.
- [Saccharomyces boulardii: diarrhea, toxins and safety](https://nutrifit.health/knowledge/saccharomyces-boulardii-antibiotic-diarrhea-c-difficile/md): How probiotic yeast affects bacterial toxins, what trials show about antibiotic-associated diarrhea, why current CDI guidance differs, and when fungemia risk rules out use.
- [Akkermansia muciniphila: mucus ecology, molecular signals and metabolic health](https://nutrifit.health/knowledge/akkermansia-muciniphila-mucus-layer-metabolic-health/md): How Akkermansia processes MUC2 glycans, supports microbial cross-feeding and interacts with the host through proteins and membrane lipids. Live and pasteurized preparations, four human trials including positive and null 2026 outcomes, and the limits of stool-based treatment decisions.
- [L-ornithine-L-aspartate (LOLA): the urea cycle, glutamine and hyperammonemia](https://nutrifit.health/knowledge/l-ornithine-l-aspartate-lola-urea-cycle-hyperammonemia/md): How LOLA substrates connect urea synthesis, liver zonation and muscle glutamine metabolism, and what randomized trials actually show about hepatic encephalopathy, recurrence, acute liver failure and safety.
- [Essential phospholipids and phosphatidylcholine: liver membranes, lipid remodeling, and the limits of “repair”](https://nutrifit.health/knowledge/essential-phospholipids-phosphatidylcholine-liver-repair/md): DLinPC chemistry, digestion and remodeling, mitochondria, PLA2, fibrosis, VLDL and bile. How model effects differ from MANPOWER, VA and EXCEL outcomes and clinical liver repair.
- [Silymarin and silibinin: membranes, rRNA and clinical evidence](https://nutrifit.health/knowledge/silymarin-silibinin-hepatocyte-membrane-stabilization/md): Extract composition, stereochemistry, oral and IV exposure, membrane experiments, OATP1B3, rat Pol I/rRNA, redox and fibrosis pathways. Primary liver trials, negative endpoints, interactions and formulation limits.
- [Bile acids, FXR and TGR5: the gut–liver axis](https://nutrifit.health
