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1.  Association between tobacco use and the upper gastrointestinal microbiome among Chinese men 
Cancer causes & control : CCC  2015;26(4):581-588.
Tobacco causes many adverse health conditions and may alter the upper gastrointestinal (UGI) microbiome. However, the few studies that studied the association between tobacco use and the microbiome were small and underpowered. Therefore, we investigated the association between tobacco use and the UGI microbiome in Chinese men.
We included 278 men who underwent esophageal cancer screening in Henan Province, China. Men were categorized as current, former, or never smokers from questionnaire data. UGI tract bacterial cells were characterized using the Human Oral Microbial Identification Microarray. Counts of unique bacterial species and genera estimated alpha diversity. For beta diversity, principal coordinate (PCoA) vectors were generated from an unweighted UniFrac distance matrix. Polytomous logistic regression models were used for most analyses.
Of the 278 men in this study, 46.8% were current smokers and 12.6% were former smokers. Current smokers tended to have increased alpha diversity (mean: 42.3 species) compared to never smokers (mean: 38.9 species). For a 10 species increase, the odds ratio (OR) for current smoking was 1.29 (95% CI: 1.04–1.62). Beta diversity was also associated with current smoking. The first two PCoA vectors were strongly associated with current smoking (PCoA1 OR 0.66; 95% CI: 0.51–0.87; PCoA2 OR 0.73; 95% CI: 0.56–0.95). Furthermore, Dialister invisus and Megasphaera micronuciformis were more commonly detected in current smokers than in never smokers.
Current smoking was associated with both alpha and beta diversity in the UGI tract. Future work should consider how the UGI microbiome is associated with smoking related diseases.
PMCID: PMC4852095  PMID: 25701246
China; microbiome; tobacco; upper gastrointestinal tract
2.  Beta-Diversity Metrics of the Upper Digestive Tract Microbiome are Associated with Body Mass Index 
Obesity (Silver Spring, Md.)  2015;23(4):862-869.
Studies of the fecal microbiome have implicated the gut microbiota in obesity, but few studies examined the microbial diversity at other sites. We explored the association between obesity and the upper gastrointestinal (UGI) microbial diversity.
The UGI microbiome of 659 healthy Chinese adults with a measured body mass index (BMI) range of 15.0 to 35.7 was characterized using the 16S rRNA gene DNA microarray (HOMIM).
In multivariate-adjusted models, alpha diversity was not associated with BMI. However, beta diversity, assessed by principal coordinate vectors generated from an unweighted unifrac distance matrix of pairwise comparisons, was associated with BMI (third and fourth vectors, p=0.0132 and p=0.0280, respectively). Moreover, beta diversity, assessed by cluster membership (3 clusters), was also associated with BMI; individuals in the first cluster (median BMI 22.35, odds ratio (OR)=0.48, 95% confidence interval (CI)=0.05–4.34) and second cluster (median BMI 22.55, OR=0.26, 95% CI=0.09–0.75) were significantly less likely to be obese (BMI ≥27.5) than those in the third cluster (median BMI 23.59).
A beta-diversity metric of the UGI microbiome is associated with a four-fold difference in obesity risk in this Asian population. Future studies should address whether the UGI microbiome plays a causal role in obesity.
PMCID: PMC4380747  PMID: 25755147
beta-diversity; body mass index; Chinese; microbiome; obesity; upper gastrointestinal tract
3.  Association between upper digestive tract microbiota and cancer predisposing states in the esophagus and stomach 
The human upper digestive tract microbial community (microbiota) is not well characterized and few studies have explored how it relates to human health. We examined the relationship between upper digestive tract microbiota and two cancer predisposing states, serum pepsinogen I/pepsinogen II ratio (PGI/II) (predictor of gastric cancer risk), and esophageal squamous dysplasia (ESD) (the precursor lesion of esophageal squamous cell carcinoma (ESCC)) in a cross-sectional design.
The Human Oral Microbe Identification Microarray was used to test for the presence of 272 bacterial species in 333 upper digestive tract samples from a Chinese cancer screening cohort. Serum PGI and PGII were determined by enzyme-linked immunosorbent assays. ESD was determined by chromoendoscopy with biopsy.
Lower microbial richness (number of bacterial genera per sample) was significantly associated with lower PGI/II ratio (P=0.034) and the presence of ESD (P=0.018). We conducted principal component (PC) analysis on a β-diversity matrix (pairwise difference in microbiota), and observed significant correlations between PC1, PC3 and PGI/II (P=0.004, 0.009 respectively), and between PC1 and ESD (P=0.003).
lower microbial richness in upper digestive tract was independently associated with both cancer predisposing states in the esophagus and stomach (presence of ESD and lower PGI/II).
PMCID: PMC4011942  PMID: 24700175
microbiota; gastric cancer; esophageal squamous cell carcinoma; esophageal squamous dysplasia; serum pepsinogen I/pepsinogen II ratio
4.  Serum cytokine analysis in a positive chemoprevention trial: Selenium, Interleukin-2 and an association with squamous preneoplastic disease 
This study represents a multiplex cytokine analysis of serum from a 10-month randomized, controlled trial of 238 subjects that investigated the effects of selenomethionine and/or celecoxib in subjects with mild or moderate esophageal squamous dysplasia. The original chemoprevention study found that among those with mild dysplasia, selenomethionine treatment favorably altered dysplasia grade. The current analysis found that selenomethionine down-regulated IL-2 by 9% (p=0.04), while celecoxib down-regulated IL-7 by 11% (p=0.006) and up-regulated IL-13 by 17% (p=0.008). In addition, an increase in IL-7 tertile from baseline to t10 was significantly associated with an increase in dysplasia grade, both overall (OR=1.47, p=0.03) and among those with mild dysplasia at t0 (OR=2.53 p=0.001). An increase in IL-2 tertile from baseline to t10 was also non-significantly associated with worsening dysplasia for all participants (OR=1.32 p=0.098), and significantly associated with worsening dysplasia among those with mild dysplasia at baseline (OR=2.0 p=0.01). The association of increased IL-2 with worsening dysplasia remained significant in those on selenomethionine treatment who began the trial with mild dysplasia (OR=2.52 p=0.03). The current study shows that selenomethionine supplementation decreased serum IL-2 levels, while celecoxib treatment decreased IL-7 levels and increased IL-13 levels during a 10 month randomized chemoprevention trial. An increase in IL-2 or IL-7 was associated with increased severity of dysplasia over the course of the trial, especially in those who began the trial with mild dysplasia. The favorable effect of selenomethionine on esophageal dysplasia in the original trial may have been mediated in part by its effect on reducing levels of IL-2.
PMCID: PMC2900463  PMID: 20587703
chemoprevention; interleukin-2; preneoplasia; gastrointestinal tract; selenium
5.  Total and Cancer Mortality After Supplementation With Vitamins and Minerals: Follow-up of the Linxian General Population Nutrition Intervention Trial 
The General Population Nutrition Intervention Trial was a randomized primary esophageal and gastric cancer prevention trial conducted from 1985 to 1991, in which 29 584 adult participants in Linxian, China, were given daily vitamin and mineral supplements. Treatment with “factor D,” a combination of 50 μg selenium, 30 mg vitamin E, and 15 mg beta-carotene, led to decreased mortality from all causes, cancer overall, and gastric cancer. Here, we present 10-year follow-up after the end of active intervention.
Participants were assessed by periodic data collection, monthly visits by village health workers, and quarterly review of the Linxian Cancer Registry. Hazard ratios (HRs) and 95% confidence intervals (CIs) for the cumulative effects of four vitamin and mineral supplementation regimens were calculated using adjusted proportional hazards models.
Through May 31, 2001, 276 participants were lost to follow-up; 9727 died, including 3242 from cancer (1515 from esophageal cancer and 1199 from gastric cancer). Participants who received factor D had lower overall mortality (HR = 0.95, 95% CI = 0.91 to 0.99; P = .009; reduction in cumulative mortality from 33.62% to 32.19%) and gastric cancer mortality (HR = 0.89, 95% CI = 0.79 to 1.00; P = .043; reduction in cumulative gastric cancer mortality from 4.28% to 3.84%) than subjects who did not receive factor D. Reductions were mostly attributable to benefits to subjects younger than 55 years. Esophageal cancer deaths between those who did and did not receive factor D were not different overall; however, decreased 17% among participants younger than 55 (HR = 0.83, 95% CI = 0.71 to 0.98; P = .025) but increased 14% among those aged 55 years or older (HR = 1.14, 95% CI = 1.00 to 1.30; P = .47). Vitamin A and zinc supplementation was associated with increased total and stroke mortality; vitamin C and molybdenum supplementation, with decreased stroke mortality.
The beneficial effects of selenium, vitamin E, and beta-carotene on mortality were still evident up to 10 years after the cessation of supplementation and were consistently greater in younger participants. Late effects of other supplementation regimens were also observed.
PMCID: PMC2664089  PMID: 19318634

Results 1-5 (5)