title: Subclinical atherosclerosis is linked to small intestinal bacterial overgrowthviavitamin K2-dependent mechanisms.
abstract: OBJECTIVE
  To assess the rate of matrix Gla-protein carboxylation in patients with small intestinal bacterial overgrowth (SIBO) and to decipher its association with subclinical atherosclerosis.
  
  
  METHODS
  Patients with suspected SIBO who presented with a low risk for cardiovascular disease and showed no evidence of atherosclerotic plaques were included in the study. A glucose breath test was performed in order to confirm the diagnosis of SIBO and vascular assessment was carried out by ultrasound examination. Plasma levels of the inactive form of MGP (dephosphorylated-uncarboxylated matrix Gla-protein) were quantified by ELISA and vitamin K2 intake was estimated using a food frequency questionnaire.
  
  
  RESULTS
  Thirty-nine patients were included in the study. SIBO was confirmed in 12/39 (30.8%) patients who also presented with a higher concentration of dephosphorylated-uncarboxylated matrix Gla-protein (9.5 μg/Lvs4.2 μg/L;P= 0.004). Arterial stiffness was elevated in the SIBO group (pulse-wave velocity 10.25 m/svs7.68 m/s;P= 0.002) and this phenomenon was observed to correlate linearly with the levels of dephosphorylated-uncarboxylated matrix Gla-protein (β = 0.220,R2= 0.366,P= 0.03). Carotid intima-media thickness and arterial calcifications were not observed to be significantly elevated as compared to controls.
  
  
  CONCLUSIONS
  SIBO is associated with reduced matrix Gla-protein activation as well as arterial stiffening. Both these observations are regarded as important indicators of subclinical atherosclerosis. Hence, screening for SIBO, intestinal decontamination and supplementation with vitamin K2 has the potential to be incorporated into clinical practice as additional preventive measures.
authors.affiliation: Francesca Romana Ponziani, Maurizio Pompili, Maria Assunta Zocco, Antonio Gasbarrini, Internal Medicine, Gastroenterology and Hepatology, Agostino Gemelli Hospital, 00168 Rome, Italy.
authors.forename: Francesca Romana
authors.initials: FR
authors.lastname: Ponziani
authors.affiliation: Francesca Romana Ponziani, Maurizio Pompili, Maria Assunta Zocco, Antonio Gasbarrini, Internal Medicine, Gastroenterology and Hepatology, Agostino Gemelli Hospital, 00168 Rome, Italy.
authors.forename: Maurizio
authors.initials: M
authors.lastname: Pompili
authors.affiliation: Francesca Romana Ponziani, Maurizio Pompili, Maria Assunta Zocco, Antonio Gasbarrini, Internal Medicine, Gastroenterology and Hepatology, Agostino Gemelli Hospital, 00168 Rome, Italy.
authors.forename: Enrico
authors.initials: E
authors.lastname: Di Stasio
authors.affiliation: Francesca Romana Ponziani, Maurizio Pompili, Maria Assunta Zocco, Antonio Gasbarrini, Internal Medicine, Gastroenterology and Hepatology, Agostino Gemelli Hospital, 00168 Rome, Italy.
authors.forename: Maria Assunta
authors.initials: MA
authors.lastname: Zocco
authors.affiliation: Francesca Romana Ponziani, Maurizio Pompili, Maria Assunta Zocco, Antonio Gasbarrini, Internal Medicine, Gastroenterology and Hepatology, Agostino Gemelli Hospital, 00168 Rome, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Gasbarrini
authors.affiliation: Francesca Romana Ponziani, Maurizio Pompili, Maria Assunta Zocco, Antonio Gasbarrini, Internal Medicine, Gastroenterology and Hepatology, Agostino Gemelli Hospital, 00168 Rome, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Flore
mesh_terms: D000328:Adult; D050197:Atherosclerosis / Q000382:microbiology*; D001424:Bacterial Infections; D002135:Calcium-Binding Proteins / Q000378:metabolism; D002318:Cardiovascular Diseases / Q000382:microbiology; D059168:Carotid Intima-Media Thickness; D019587:Dietary Supplements; D004797:Enzyme-Linked Immunosorbent Assay; D016326:Extracellular Matrix Proteins / Q000378:metabolism; D005260:Female; D000069196:Gastrointestinal Microbiome; D006801:Humans; D007422:Intestines / Q000382:microbiology*; D008297:Male; D008875:Middle Aged; D012306:Risk; D011795:Surveys and Questionnaires; D014463:Ultrasonography; D061205:Vascular Calcification; D059289:Vascular Stiffness; D024482:Vitamin K 2 / Q000378:metabolism*; D000097568:Matrix Gla Protein
chemical_list: D002135:Calcium-Binding Proteins; D016326:Extracellular Matrix Proteins; D024482:Vitamin K 2; D000097568:Matrix Gla Protein
keywords: Atherosclerosis; Cardiovascular disease risk; Dysbiosis; Small intestinal bacterial overgrowth; Vitamin K