title: Markers of systemic exposures to products of intestinal bacteria in a dietary intervention study.
abstract: OBJECTIVE
  Systemic exposures to intestinal bacteria may play a role in the etiology of the chronic, low-grade inflammation that is associated with western diets. Production of lipopolysaccharide-binding protein (LBP) is one biomarker of increased exposures to intestinal bacteria. This study evaluated whether changes in diet quality could affect serum LBP.
  
  
  METHODS
  This was a randomized, controlled trial of Mediterranean and Healthy Eating diets over 6 months in 120 healthy subjects at increased risk of colon cancer. Blood samples obtained before and after intervention were analyzed for LBP, branched-chain fatty acids characteristic of intestinal bacteria, micronutrients and cytokines. Data were analyzed for changes in LBP over time and for predictors of LBP.
  
  
  RESULTS
  Serum concentrations of branched-chain bacterial fatty acids declined significantly in both diet groups. However, there was no significant change in mean serum LBP concentrations with either diet intervention. In serum, LBP was positively associated with CRP and negatively associated with carotenoids both before and after intervention. After intervention, LBP was predicted positively by both CRP and bacterial fatty acid concentrations in serum, and negatively by serum carotenoids and the ω3/ω6 fatty acid ratio. This model accounted for 30 % of the inter-individual variation in serum LBP after intervention.
  
  
  CONCLUSIONS
  These results indicate that dietary intervention over 6 months was insufficient to alter serum LBP. The relationships with inflammation-related markers, however, indicate that anti-inflammatory strategies other than changes in diet quality, such as weight loss or improved fitness, may have more potential for reducing systemic markers of LPS exposures in well-nourished populations.
authors.affiliation: Department of Family Medicine, University of Michigan, 1500 E. Medical Center Drive, Room 2150 Cancer Center, Ann Arbor, MI, 48109-5930, USA.
authors.forename: Faith I
authors.initials: FI
authors.lastname: Umoh
authors.affiliation: Department of Pathology and Karmanos Cancer Institute, Wayne State University, Detroit, MI, 48201, USA.
authors.forename: Ikuko
authors.initials: I
authors.lastname: Kato
authors.affiliation: Department of Family Medicine, University of Michigan, 1500 E. Medical Center Drive, Room 2150 Cancer Center, Ann Arbor, MI, 48109-5930, USA.
authors.forename: Jianwei
authors.initials: J
authors.lastname: Ren
authors.affiliation: Department of Family Medicine, University of Michigan, 1500 E. Medical Center Drive, Room 2150 Cancer Center, Ann Arbor, MI, 48109-5930, USA.
authors.forename: Phillip L
authors.initials: PL
authors.lastname: Wachowiak
authors.affiliation: Department of Family Medicine, University of Michigan, 1500 E. Medical Center Drive, Room 2150 Cancer Center, Ann Arbor, MI, 48109-5930, USA.
authors.forename: Mack T
authors.initials: MT
authors.lastname: Ruffin
authors.affiliation: Department of Internal Medicine, University of Michigan, Ann Arbor, MI, 48109-5930, USA.
authors.forename: D Kim
authors.initials: DK
authors.lastname: Turgeon
authors.affiliation: Department of Family Medicine, University of Michigan, 1500 E. Medical Center Drive, Room 2150 Cancer Center, Ann Arbor, MI, 48109-5930, USA.|Department of Statistics, University of Michigan, Ann Arbor, MI, 48109-5930, USA.
authors.forename: Ananda
authors.initials: A
authors.lastname: Sen
authors.affiliation: Department of Internal Medicine, University of Michigan, Ann Arbor, MI, 48109-5930, USA.|Department of Pharmacology, University of Michigan, Ann Arbor, MI, 48109-5930, USA.
authors.forename: Dean E
authors.initials: DE
authors.lastname: Brenner
authors.affiliation: Department of Family Medicine, University of Michigan, 1500 E. Medical Center Drive, Room 2150 Cancer Center, Ann Arbor, MI, 48109-5930, USA. zoralong@umich.edu.
authors.forename: Zora
authors.initials: Z
authors.lastname: Djuric
mesh_terms: D000209:Acute-Phase Proteins; D015415:Biomarkers / Q000097:blood*; D015992:Body Mass Index; D002097:C-Reactive Protein / Q000378:metabolism; D002338:Carotenoids / Q000097:blood; D002352:Carrier Proteins / Q000097:blood*; D008076:Cholesterol, HDL / Q000097:blood; D008078:Cholesterol, LDL / Q000097:blood; D003110:Colonic Neoplasms / Q000517:prevention & control; D016207:Cytokines / Q000097:blood; D000072001:Diet, Healthy; D038441:Diet, Mediterranean; D015525:Fatty Acids, Omega-3 / Q000097:blood; D043371:Fatty Acids, Omega-6 / Q000097:blood; D005638:Fruit; D000069196:Gastrointestinal Microbiome; D006801:Humans; D007249:Inflammation / Q000097:blood / Q000175:diagnosis; D016014:Linear Models; D008562:Membrane Glycoproteins / Q000097:blood*; D008875:Middle Aged; D012307:Risk Factors; D014280:Triglycerides / Q000097:blood; D014675:Vegetables; D000099231:Lipopolysaccharide-Binding Protein
chemical_list: D000209:Acute-Phase Proteins; D015415:Biomarkers; D002097:C-Reactive Protein; D002338:Carotenoids; D002352:Carrier Proteins; D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D016207:Cytokines; D015525:Fatty Acids, Omega-3; D043371:Fatty Acids, Omega-6; D008562:Membrane Glycoproteins; D014280:Triglycerides; D000099231:Lipopolysaccharide-Binding Protein
keywords: High fruit and vegetable diets; Inflammation; Intestinal bacteria; Mediterranean diet; Obesity