A communal catalogue reveals Earth's multiscale microbial diversity

Our growing awareness of the microbial world's importance and diversity contrasts starkly with our limited understanding of its fundamental structure. Despite recent advances in DNA sequencing, a lack of standardized protocols and common analytical frameworks impedes comparisons among studies, hindering the development of global inferences about microbial life on Earth. Here we present a meta-analysis of microbial community samples collected by hundreds of researchers for the Earth Microbiome Project. Coordinated protocols and new analytical methods, particularly the use of exact sequences instead of clustered operational taxonomic units, enable bacterial and archaeal ribosomal RNA gene sequences to be followed across multiple studies and allow us to explore patterns of diversity at an unprecedented scale. The result is both a reference database giving global context to DNA sequence data and a framework for incorporating data from future studies, fostering increasingly complete characterization of Earth's microbial diversity.Peer reviewe

A communal catalogue reveals Earth’s multiscale microbial diversity

Our growing awareness of the microbial world’s importance and diversity contrasts starkly with our limited understanding of its fundamental structure. Despite recent advances in DNA sequencing, a lack of standardized protocols and common analytical frameworks impedes comparisons among studies, hindering the development of global inferences about microbial life on Earth. Here we present a meta-analysis of microbial community samples collected by hundreds of researchers for the Earth Microbiome Project. Coordinated protocols and new analytical methods, particularly the use of exact sequences instead of clustered operational taxonomic units, enable bacterial and archaeal ribosomal RNA gene sequences to be followed across multiple studies and allow us to explore patterns of diversity at an unprecedented scale. The result is both a reference database giving global context to DNA sequence data and a framework for incorporating data from future studies, fostering increasingly complete characterization of Earth’s microbial diversity

A pooled analysis of dietary sugar/carbohydrate intake and esophageal and gastric cardia adenocarcinoma incidence and survival in the USA

Background: During the past 40 years, esophageal/gastric cardia adenocarcinoma (EA/ GCA) incidence increased in Westernized countries, but survival remained low. A parallel increase in sugar intake, which may facilitate carcinogenesis by promoting hyperglycaemia, led us to examine sugar/carbohydrate intake in association with EA/GCA incidence and survival. Methods: We pooled 500 EA cases, 529 GCA cases and 2027 controls from two US population-based case-control studies with cases followed for vital status. Dietary intake, assessed by study-specific food frequency questionnaires, was harmonized and pooled to estimate 12 measures of sugar/carbohydrate intake. Multivariable-adjusted odds ratios (ORs) and hazard ratios [95% confidence intervals (CIs)] were calculated using multinomial logistic regression and Cox proportional hazards regression, respectively. Results: EA incidence was increased by 51-58% in association with sucrose (ORQ5vs.Q1=1.51, 95% CI=1.01-2.27), sweetened desserts/beverages (ORQ5vs.Q1=1.55, 95% CI=1.06-2.27) and the dietary glycaemic index (ORQ5vs.Q1=1.58, 95% CI=1.13-2.21). Bodymass index (BMI) and gastro-esophageal reflux disease (GERD) modified these associations (Pmultiplicative-interaction ≤ 0.05). For associations with sucrose and sweetened desserts/beverages, respectively, the OR was elevated for BMI < 25 (ORQ4-5vs.Q1-3=1.79, 95% CI=1.26-2.56 and ORQ4-5vs.Q1-3=1.45, 95% CI=1.03-2.06), but not BMI≥25 (ORQ4-5vs.Q1-3=1.05, 95% CI=0.76-1.44 and ORQ4-5vs.Q1-3=0.85, 95% CI=0.62-1.16). The EA-glycaemic index association was elevated for BMI≥25 (ORQ4-5vs.Q1-3=1.38, 95% CI=1.03-1.85), but not BMI < 25 (ORQ4-5vs.Q1-3=0.88, 95% CI=0.62-1.24). The sucrose-EA association OR for GERD < weekly was 1.58 (95% CI=1.16-2.14), but for GERD≥weekly was 1.01 (95% CI=0.70-1.47). Sugar/carbohydrate measures were not associated with GCA incidence or EA/GCA survival. Conclusions: If confirmed, limiting intake of sucrose (e.g. table sugar), sweetened desserts/ beverages, and foods that contribute to a high glycaemic index, may be plausible EA risk reduction strategies