title: The role of breast-feeding in the prevention of Helicobacter pylori infection: a systematic review.
abstract: BACKGROUND
  The benefits of breast-feeding for the prevention of infection in infants and young children have been widely recognized, but epidemiologic studies regarding the role of breast-feeding in protecting against Helicobacter pylori infection have produced conflicting results.
  
  
  METHODS
  We performed a systematic review of relevant epidemiologic studies conducted during the period 1984-2007 after abstracting data from articles that met our inclusion criteria. Study quality was assessed using the Newcastle-Ottawa scale. With use of the random effects model, we calculated the summary odds ratios (ORs) and 95% confidence intervals (CIs) for H. pylori infection according to history of breast-feeding.
  
  
  RESULTS
  For the 14 studies that met inclusion criteria, the summary OR for H. pylori infection was 0.78 (95% CI, 0.61-0.99; 1-sided P = .002). Nine of the 14 studies reported ORs of <1.0, and 6 of these studies reported statistically significant protective effects. Only 1 study reported a statistically significant OR of >1.0. In studies in which the subjects resided in middle- or low-income nations, the summary OR was 0.55 (95% CI, 0.33-0.93; P = .01), compared with 0.93 (95% CI, 0.73-1.19; P = .28) in studies in which subjects resided in high-income nations. The summary OR for studies that use the (13)C-urea breath test was 0.67 (95% CI, 0.32-1.39), compared with 0.91 (95% CI, 0.74-1.11) for studies that used the H. pylori IgG serologic test. We found no statistically significant dose-dependent protective effect against H. pylori associated with increasing duration of breast-feeding.
  
  
  CONCLUSIONS
  Breast-feeding is protective against H. pylori infection, especially in middle- and low-income nations.
authors.affiliation: School of Public Health, University of California-Berkeley, USA.
authors.forename: Eric
authors.initials: E
authors.lastname: Chak
authors.forename: George W
authors.initials: GW
authors.lastname: Rutherford
authors.forename: Craig
authors.initials: C
authors.lastname: Steinmaus
mesh_terms: D001942:Breast Feeding; D003906:Developing Countries; D005260:Female; D016481:Helicobacter Infections / Q000453:epidemiology* / Q000517:prevention & control*; D016480:Helicobacter pylori / Q000276:immunology*; D006801:Humans