Background: Methods: Results: Conclusion:

Despite tremendous interest in modulating the microbiome to improve health, the association between diet and the colonic mucosa-associated gut microbiome in healthy individuals has not been examined. To investigate the associations between Healthy Eating Index (HEI)-2005 and the colonic mucosa-associated microbiota. In this cross-sectional observational study, we analyzed bacterial community composition and structure using 16S rRNA gene (V4 region) sequencing of 97 colonic mucosal biopsies obtained endoscopically from different colon segments of 34 polyp-free participants. Dietary consumption was ascertained using an FFQ. Differences in α- and β-diversity and taxonomic relative abundances between the higher and lower score of total HEI and its components were compared, followed by multivariable analyses. The structure of the microbiota significantly differed by the scores for total HEI, total and whole fruits (HEI 1 and HEI 2), whole grains (HEI 6), milk products and soy beverages (HEI 7), and solid fat, alcohol, and added sugar (HEI 12). A lower score for total HEI and HEIs 2, 7, and 12 was associated with significantly lower richness. A lower score for total HEI was associated with significantly reduced relative abundance of Parabacteroides, Roseburia, and Subdoligranulum but higher Fusobacterium. A lower score for HEI 2 was associated with lower Roseburia but higher Bacteroides. A lower score for HEI 7 was associated with lower Faecalibacterium and Fusobacterium but higher Bacteroides. A lower score for HEI 12 was associated with lower Subdoligranulum but higher Escherichia and Fusobacterium (false discovery rate-adjusted P values <0.05). The findings were confirmed by multivariate analysis. Less abundant bacteria such as Alistipes, Odoribacter, Bilophila, and Tyzzerella were also associated with dietary quality. A lower score for total HEI-2005 was significantly associated with reduced relative abundance of potentially beneficial bacteria but increased potentially harmful bacteria in the colonic mucosa of endoscopically normal individuals.

Background: Advanced glycation end products (AGEs) are a heterogeneous group of compounds present in uncooked foods as well as in foods cooked at high

One carbon (1C) metabolism nutrients influence epigenetic regulation and they are supplied by diet and synthesized by gut microbiota. We examined the association between dietary consumption of methyl donors (methionine, betaine and choline) and B vitamins (folate, B2, B6, and B12) and the community composition and structure of the colonic mucosa-associated gut microbiota determined by 16S rRNA gene sequencing in 97 colonic biopsies of 35 men. We used the food frequency questionnaire to assess daily consumption of nutrients, and the UPARSE and SILVA databases for operational taxonomic unit classification. The difference in bacterial diversity and taxonomic relative abundance were compared between low versus high consumption of these nutrients. False discover rate (FDR) adjusted p value < 0.05 indicated statistical significance. The bacterial richness and composition differed significantly by the consumption of folate and B vitamins (p < 0.001). Compared with higher consumption, a lower consumption of these nutrients was associated with a lower abundance of Akkermansia (folate), Roseburia (vitamin B2), and Faecalibacterium (vitamins B2, B6, and B12) but a higher abundance of Erysipelatoclostridium (vitamin B2) (FDR p values < 0.05). The community composition and structure of the colonic bacteria differed significantly by dietary consumption of folate and B vitamins.

Cigarette smoking, obesity, type 2 diabetes, and, to a lesser extent, meat cooked at high temperatures are associated with pancreatic cancer. Cigarette smoke and foods cooked at higher temperatures are major environmental sources of advanced glycation end products (AGE). AGEs accumulate during hyperglycemia and elicit oxidative stress and inflammation through interaction with the receptor for AGEs (RAGE). Soluble RAGE (sRAGE) acts as an anti-inflammatory factor to neutralize AGEs and block the effects mediated by RAGE. In this study, we investigated the associations of prediagnostic measures of N^ε-(carboxymethyl)-lysine (CML)-AGE and sRAGE with pancreatic cancer in a case–cohort study within a cohort of 29,133 Finnish male smokers. Serum samples and exposure information were collected at baseline (1985–1988). We measured CML-AGE, sRAGE, glucose, and insulin concentrations in fasting serum from 255 incident pancreatic cancer cases that arose through April 2005 and from 485 randomly sampled subcohort participants. Weighted Cox proportional hazard regression models were used to calculate relative risks (RR) and 95% CI, adjusted for age, years of smoking, and body mass index. CML-AGE and sRAGE were mutually adjusted. CML-AGE levels were not associated with pancreatic cancer [fifth compared with first quintile, RR (95% CI): 0.68 (0.38–1.22), P_trend = 0.27]. In contrast, sRAGE levels were inversely associated with pancreatic cancer [fifth compared with first quintile, RR (95% CI): 0.46 (0.23–0.73), P_trend = 0.002]. Further adjustment for glucose or insulin levels did not change the observed associations. Our findings suggest that sRAGE is inversely associated with pancreatic cancer risk among Finnish male smokers. Cancer Res; 71(10); 3582–9. ©2011 AACR.