title: Gut colonization with methanobrevibacter smithii is associated with childhood weight development.
abstract: OBJECTIVE
  To prospectively investigate the presence and counts of archaea in feces of 472 children in association with weight development from 6 to 10 years of age.
  
  
  METHODS
  Within the KOALA Birth Cohort Study, a single fecal sample from each child was analyzed by quantitative polymerase chain reaction to quantify archaea (Methanobrevibacter smithii, Methanosphera stadtmanae). Anthropometric outcomes (overweight [body mass index {BMI} ≥ 85th percentile], age- and sex-standardized BMI, weight, and height z-scores) were repeatedly measured at ages (mean ± SD) of 6.2 ± 0.5, 6.8 ± 0.5, 7.8 ± 0.5, and 8.8 ± 0.5 years. Generalized estimating equation was used for statistical analysis while controlling for confounders.
  
  
  RESULTS
  Methanobrevibacter smithii colonization was associated with an increased risk of overweight (adjusted odds ratio [OR] = 2.69; 95% confidence interval [CI] 0.96-7.54) from 6 to 10 years of age. Children with high levels (>7 log10 copies/g feces) of this archaeon were at highest risk for overweight (OR = 3.27; 95% CI 1.09-9.83). Moreover, M. smithii colonization was associated with higher weight z-scores (adj. β 0.18; 95% CI 0.00-0.36), but not with height. For BMI z-scores, the interaction (P = 0.008) between M. smithii and age was statistically significant, implying children colonized with M. smithii had increasing BMI z-scores with age.
  
  
  CONCLUSIONS
  Presence and higher counts of M. smithii in the gut of children are associated with higher weight z-scores, higher BMI z-scores, and overweight.
authors.affiliation: Top Institute Food and Nutrition, Wageningen, the Netherlands.|Department of Epidemiology, Maastricht University, CAPHRI School for Public Health and Primary Care, Maastricht, the Netherlands.
authors.forename: Catherine A
authors.initials: CA
authors.lastname: Mbakwa
authors.affiliation: Department of Epidemiology, Maastricht University, CAPHRI School for Public Health and Primary Care, Maastricht, the Netherlands.|Department of Medical Microbiology, Maastricht University Medical Centre, NUTRIM School for Nutrition, Toxicology and Metabolism, Maastricht, the Netherlands.
authors.forename: John
authors.initials: J
authors.lastname: Penders
authors.affiliation: Department of Medical Microbiology, Maastricht University Medical Centre, NUTRIM School for Nutrition, Toxicology and Metabolism, Maastricht, the Netherlands.
authors.forename: Paul H
authors.initials: PH
authors.lastname: Savelkoul
authors.affiliation: Department of Epidemiology, Maastricht University, CAPHRI School for Public Health and Primary Care, Maastricht, the Netherlands.
authors.forename: Carel
authors.initials: C
authors.lastname: Thijs
authors.affiliation: Department of Epidemiology, Maastricht University, CAPHRI School for Public Health and Primary Care, Maastricht, the Netherlands.|Department of Epidemiology, Maastricht University, CARIM School for Cardiovascular Diseases, Maastricht, the Netherlands.
authors.forename: Pieter C
authors.initials: PC
authors.lastname: Dagnelie
authors.affiliation: Department of Epidemiology, Maastricht University, CAPHRI School for Public Health and Primary Care, Maastricht, the Netherlands.
authors.forename: Monique
authors.initials: M
authors.lastname: Mommers
authors.affiliation: Department of Epidemiology, Maastricht University, CAPHRI School for Public Health and Primary Care, Maastricht, the Netherlands.|Department of Epidemiology, Maastricht University, CARIM School for Cardiovascular Diseases, Maastricht, the Netherlands.
authors.forename: Ilja C W
authors.initials: IC
authors.lastname: Arts
mesh_terms: D000367:Age Factors; D000886:Anthropometry; D001827:Body Height; D015992:Body Mass Index; D001835:Body Weight; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D005243:Feces / Q000382:microbiology*; D005260:Female; D006801:Humans; D008297:Male; D017013:Methanobacteriaceae / Q000254:growth & development; D041581:Methanobrevibacter / Q000254:growth & development*; D016017:Odds Ratio; D050177:Overweight / Q000382:microbiology*; D011446:Prospective Studies