Component
Intestinal epithelium
Epithelial lining of the intestine.
3 recorded relationships. Experimental role, claim status and evidence remain attached to each record.
How nutrients influence it
Every nutrient with a recorded effect on this component, credited to the nutrient that acted rather than the chapter that recorded it. Open a nutrient to see the findings and the conditions they were measured under.
Other things that act on it
Enzymes, hormones, genes, and other components with a recorded effect. These are not nutrients, so they do not count toward the arrows above. Each finding names the chapter that recorded it.
How nutrients reach it in more than one step
Chains of two or more recorded steps that end here, grouped by the nutrient they start from. Each step is a separate finding, so a chain is a route a mechanism could take, not proof that it does.
Tracing routes…
What it does
Every recorded relationship this component is part of, grouped by its role. Plain wording comes first; the technical statement follows.
What acts on it
Nattokinase is a moderately absorbed biomolecule whose transport through enterocytes is energy- and time-dependent.
Experimental context and source evidence
- duration
- Not stated here
- evidence_access
- Primary PubMed abstract and indexed metadata reviewed. Full-text method details not stated here remain unresolved.
- experimental_model
- Caco-2 cell monolayer and rat
- exposure
- Nattokinase
- limitations
- Energy dependence rules out passive paracellular leak as the whole story. Crossing an epithelium in a monolayer or an everted sac is not the same as arriving intact and active in human plasma, which is the step nothing in this chapter measures.
- organism
- Caco-2 cell monolayer and rat
- plain_language
- Nattokinase is a moderately absorbed biomolecule whose transport through enterocytes is energy- and time-dependent.
- primary_references
- Study on the transport and internalisation mechanism of dietary supplement nattokinase in the small intestine using animal and Caco-2 cell monolayer models. (2023) https://pubmed.ncbi.nlm.nih.gov/37971898/ DOI: 10.1080/00498254.2023.2284249
- route
- In vitro
- tissue
- Intestinal epithelium, everted gut sac and ligated loop models
Nattokinase: what the purified enzyme cleaves, what survives being eaten, and the gap between the two (2026-09-23) · lines 774–774
Original AI-assisted curation built from a supplied entity-first document of 105 entities and 129 claims. Every reference in that document was resolved against live PubMed with its abstract read and its DOI cross-checked on 2026-09-23, and the EFSA novel-food opinion was retrieved and read in full. That check corrected two PMIDs that pointed at unrelated papers, two DOIs, and two papers recorded as carrying no erratum that do carry one; it also reversed three findings the supplied document had stated backwards. Two papers carry a published correction, recorded as such and not as a retraction. Three sources are not indexed in PubMed and are cited by what they have. Laboratory lineages are recorded, so the four papers from one group, the three from another and the two readings of a single applicant dossier cannot be counted as separate lines of support. Study-specific doses, units, populations and limitations retained; activity units are never converted between systems. Not publisher full text. · supports · Caco-2 cell monolayer and rat · source_derived_draft · unverified_draft
Nattokinase is a moderately absorbed biomolecule whose transport through enterocytes is energy- and time-dependent.
Complete structured claim and evidenceSLC19A3 protein was detected in human enterocyte brush-border membranes, with no basolateral signal.
Experimental context and source evidence
- evidence-scope
- Small-intestinal membranes; Caco-2 cells
- evidence_locator
- Native membrane Western blots; polarized Caco-2 imaging
- evidence_spans
- [{"source_document": "artifacts/thiamine_transport_sources/said-2004-intestinal-transport-source-record.json", "source_field": "resultList.result[0].abstractText", "start_char": 0, "end_char": 1710}]
- experimental_model
- Native human enterocyte membranes and polarized Caco-2 cells; imaging, immunoblotting and siRNA.
- limitations
- Localization alone does not measure net absorption.
- nutrient_topic
- Thiamine research collection; topical membership is not evidence of a direct dietary effect. · Thiamine (vitamin B1)
- organism
- Homo sapiens
- plain_language
- The transporter sits on the intestinal surface facing the lumen.
- primary_references
- [said-2004-intestinal-transport] Expression and functional contribution of hTHTR-2 in thiamin absorption in human intestine (2004). https://pubmed.ncbi.nlm.nih.gov/14615284/ DOI: 10.1152/ajpgi.00361.2003
- spatial_context
- Apical brush-border membrane.
- tissue_or_cell_type
- Small-intestinal membranes; Caco-2 cells
Thiamine: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 193–206
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Native human enterocyte membranes and polarized Caco-2 cells; imaging, immunoblotting and siRNA. · source_derived_draft · unverified_draft
### b1-slc19a3-enterocyte-apical SLC19A3 protein was detected in human enterocyte brush-border membranes, with no basolateral signal. Condition category: normal nutrient_topic: Thiamine research collection; topical membership is not evidence of a direct dietary effect. plain_language: The transporter sits on the intestinal surface facing the lumen. organism: Homo sapiens tissue_or_cell_type: Small-intestinal membranes; Caco-2 cells experimental_model: Native human enterocyte membranes and polarized Caco-2 cells; imaging, immunoblotting and siRNA. limitations: Localization alone does not measure net absorption. evidence_locator: Native membrane Western blots; polarized Caco-2 imaging spatial_context: Apical brush-border membrane. evidence_spans: [{"source_document": "artifacts/thiamine_transport_sources/said-2004-intestinal-transport-source-record.json", "source_field": "resultList.result[0].abstractText", "start_char": 0, "end_char": 1710}] evidence-scope: Small-intestinal membranes; Caco-2 cells [said-2004-intestinal-transport] Expression and functional contribution of hTHTR-2 in thiamin absorption in human intestine (2004). https://pubmed.ncbi.nlm.nih.gov/14615284/ DOI: 10.1152/ajpgi.00361.2003
Complete structured claim and evidenceSLC44A4 isoform-1 fusion protein predominantly localized to the apical domain of polarized MDCK cells.
Experimental context and source evidence
- evidence-scope
- ARPE19; MDCK; human colon
- evidence_locator
- Figure 8
- evidence_spans
- [{"source_document": "artifacts/thiamine_transport_sources/PMC3924303.txt", "start_char": 47362, "end_char": 48692}]
- experimental_model
- Human SLC44A4 isoforms expressed in ARPE19 cells; polarized MDCK imaging.
- limitations
- Canine model expressing human protein; not direct transepithelial flux.
- nutrient_topic
- Thiamine research collection; topical membership is not evidence of a direct dietary effect. · Thiamine (vitamin B1)
- organism
- Human constructs; human and canine host cells
- plain_language
- Its membrane targeting fits entry from the gut lumen.
- primary_references
- [nabokina-2014-slc44a4] Molecular identification and functional characterization of the human colonic thiamine pyrophosphate transporter (2014). https://pmc.ncbi.nlm.nih.gov/articles/PMC3924303/ DOI: 10.1074/jbc.M113.528257
- spatial_context
- Apical membrane of polarized epithelial model.
- tissue_or_cell_type
- ARPE19; MDCK; human colon
Thiamine: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 545–558
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Human SLC44A4 isoforms expressed in ARPE19 cells; polarized MDCK imaging. · source_derived_draft · unverified_draft
### b1-slc44a4-apical-targeting SLC44A4 isoform-1 fusion protein predominantly localized to the apical domain of polarized MDCK cells. Condition category: normal nutrient_topic: Thiamine research collection; topical membership is not evidence of a direct dietary effect. plain_language: Its membrane targeting fits entry from the gut lumen. organism: Human constructs; human and canine host cells tissue_or_cell_type: ARPE19; MDCK; human colon experimental_model: Human SLC44A4 isoforms expressed in ARPE19 cells; polarized MDCK imaging. limitations: Canine model expressing human protein; not direct transepithelial flux. evidence_locator: Figure 8 spatial_context: Apical membrane of polarized epithelial model. evidence_spans: [{"source_document": "artifacts/thiamine_transport_sources/PMC3924303.txt", "start_char": 47362, "end_char": 48692}] evidence-scope: ARPE19; MDCK; human colon [nabokina-2014-slc44a4] Molecular identification and functional characterization of the human colonic thiamine pyrophosphate transporter (2014). https://pmc.ncbi.nlm.nih.gov/articles/PMC3924303/ DOI: 10.1074/jbc.M113.528257
Complete structured claim and evidence
The events it takes part in
A mechanism often involves more than two components. These are the full events, with every participant and its role.
Situations it appears in
Low-supply and faulty-machinery situations recorded in the chapters where this component plays a part.
In the sources
Preserved passages that mention this component, quoted exactly. Open one to read it in context.
Open hypotheses
Proposed ideas that involve this component. They are labeled as hypotheses and do not change any recorded statement.
This is a research prototype built from draft material. It is not medical advice, and its statements still await verification against the original studies.