{"id":"37e44556-4064-5394-bbe5-4a29fc97d805","stable_key":"31b1baa4-4113-5541-b9e7-fe44a5253a07:fecal-k-null","predicate":"no_detected_change_in_recorded_experiment","statement":"Longitudinal fecal menaquinone patterns did not associate significantly with glycemia, insulin resistance or inflammatory markers in the recorded cohort.","claim_class":"observational","status":"source_recorded","evidence_grade":"ungraded","direction":"neutral","is_public":true,"mechanism_event_id":"f26fa49b-078e-51cc-8ef7-d74d661dd870","mechanism_event_label":"Longitudinal fecal menaquinone patterns did not associate significantly with glycemia, insulin resistance or inflammatory markers in the recorded cohort.","subject":{"id":"b5cf80a2-c423-5ff5-806e-fa37ddaf7303","slug":"k2","display_name":"Vitamin K2 / menaquinone family","entity_type_key":"chemical_species"},"object":{"id":"c61df95c-c87f-5c11-9d3a-81be53d9c246","slug":"human-fecal-menaquinone-metabolic-association","display_name":"Human fecal menaquinone association with glycemia, insulin resistance and inflammation","entity_type_key":"cellular_process"},"evidence_count":1,"mechanism_event":{"id":"f26fa49b-078e-51cc-8ef7-d74d661dd870","stable_key":"31b1baa4-4113-5541-b9e7-fe44a5253a07:fecal-k-null-event","event_type":"experimental_observation","label":"Longitudinal fecal menaquinone patterns did not associate significantly with glycemia, insulin resistance or inflammatory markers in the recorded cohort.","description":"**Fecal vitamin K is not absorbed vitamin K.** In 77 overweight Chinese adults, fecal menaquinone patterns associated with microbial composition. A diet intervention decreased fecal MK-4, MK-6 and MK-8, but longitudinal menaquinone patterns did not associate with glycemia, insulin resistance or inflammation. Separately, human UBIAD1 silencing reduced MK-4 biosynthesis in labeled-precursor experiments; UBIAD1 is a host prenyltransferase, not a shikimate-pathway enzyme. Neither result proves that microbial shikimate output determines tissue vitamin-K adequacy. [Fecal menaquinone profiles of overweight adults are associated with gut microbiota composition during a gut microbiota-targeted dietary intervention.](https://pubmed.ncbi.nlm.nih.gov/26016865/) [Identification of UBIAD1 as a novel human menaquinone-4 biosynthetic enzyme.](https://pubmed.ncbi.nlm.nih.gov/20953171/)","status":"provisional","compartment":null,"participants":[{"entity":{"id":"b5cf80a2-c423-5ff5-806e-fa37ddaf7303","slug":"k2","display_name":"Vitamin K2 / menaquinone family","entity_type_key":"chemical_species"},"role":"tested factor","stoichiometry":null,"state_label":"as reported","sequence_order":0,"notes":""},{"entity":{"id":"c61df95c-c87f-5c11-9d3a-81be53d9c246","slug":"human-fecal-menaquinone-metabolic-association","display_name":"Human fecal menaquinone association with glycemia, insulin resistance and inflammation","entity_type_key":"cellular_process"},"role":"measured outcome","stoichiometry":null,"state_label":"no_detected_change","sequence_order":1,"notes":""}]},"contexts":[{"dimension":"evidence_access","value_text":"Primary indexed abstract reviewed; full results, tables and supplements not independently extracted.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"77 overweight Chinese adults during a diet intervention.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"interpretation_status","value_text":"Source-derived extraction of a fact-checked reference; access is explicit, not independent raw-data verification.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Observational association null; not proof of absence of every vitamin-K effect or absorbed exposure.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"Longitudinal fecal menaquinone patterns did not associate significantly with glycemia, insulin resistance or inflammatory markers in the recorded cohort.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"Fecal menaquinone profiles of overweight adults are associated with gut microbiota composition during a gut microbiota-targeted dietary intervention. | 2015 | DOI 10.3945/ajcn.115.109496 | PMID 26016865 | https://pubmed.ncbi.nlm.nih.gov/26016865/ | https://doi.org/10.3945/ajcn.115.109496","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"Identification of UBIAD1 as a novel human menaquinone-4 biosynthetic enzyme. | 2010 | DOI 10.1038/nature09464 | PMID 20953171 | https://pubmed.ncbi.nlm.nih.gov/20953171/ | https://doi.org/10.1038/nature09464","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"source_locator","value_text":"Reviewed reference lines 31-31; exact primary location described in quoted passage where extracted.","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"a7a0facd-c479-5d41-9f25-8537537d134a","evidence_kind":"source_excerpt","locator":"Lines 31-31","start_line":31,"end_line":31,"excerpt":"**Fecal vitamin K is not absorbed vitamin K.** In 77 overweight Chinese adults, fecal menaquinone patterns associated with microbial composition. A diet intervention decreased fecal MK-4, MK-6 and MK-8, but longitudinal menaquinone patterns did not associate with glycemia, insulin resistance or inflammation. Separately, human UBIAD1 silencing reduced MK-4 biosynthesis in labeled-precursor experiments; UBIAD1 is a host prenyltransferase, not a shikimate-pathway enzyme. Neither result proves that microbial shikimate output determines tissue vitamin-K adequacy. [Fecal menaquinone profiles of overweight adults are associated with gut microbiota composition during a gut microbiota-targeted dietary intervention.](https://pubmed.ncbi.nlm.nih.gov/26016865/) [Identification of UBIAD1 as a novel human menaquinone-4 biosynthetic enzyme.](https://pubmed.ncbi.nlm.nih.gov/20953171/)","model_system":"77 overweight Chinese adults during a diet intervention.","directness":"reported_statement","verification_status":"source_recorded","notes":"Exact excerpt of the retained AI-assisted reviewed reference; primary sources are cited in primary_references and access scope is retained. Not a verbatim quotation from a primary paper.","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"e6ae59de-0369-5c2f-8262-57d91302671c","stable_key":"import-31b1baa4-4113-5541-b9e7-fe44a5253a07","title":"Shikimic acid: detailed mechanisms of action (reviewed 5 October 2026)","document_type":"imported_text","citation_label":"Original AI-assisted review of primary studies and, where relevant, official regulatory records. Access level is retained per claim. Corrections, null results and unresolved questions remain explicit. Not publisher full text or independent replication.","file_path":"","sha256":"95b1f9e9577661312d67f36e156d2e49326b207f296c1c0e801a5b007fd8e283","revision_id":"cd3237f1-131a-557d-84b5-7543259807b0","review_status":"source_recorded","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}