Breast-feeding and Helicobacter pylori infection: systematic review and meta-analysis.
OBJECTIVE
To quantify the association between breast-feeding and Helicobacter pylori infection, among children and adolescents.


METHODS
We searched MEDLINE™ and Scopus™ up to January 2013. Summary relative risk estimates (RR) and 95 % confidence intervals were computed through the DerSimonian and Laird method. Heterogeneity was quantified using the I² statistic.


METHODS
Twenty-seven countries/regions; four low-income, thirteen middle-income and ten high-income countries/regions.


METHODS
Studies involving samples of children and adolescents, aged 0 to 19 years.


RESULTS
We identified thirty-eight eligible studies, which is nearly twice the number included in a previous meta-analysis on this topic. Fifteen studies compared ever v. never breast-fed subjects; the summary RR was 0·87 (95% CI 0·57, 1·32; I²=34·4%) in middle-income and 0·85 (95% CI 0·54, 1·34; I²=79·1%) in high-income settings. The effect of breast-feeding for ≥4-6 months was assessed in ten studies from middle-income (summary RR=0·66; 95% CI 0·44, 0·98; I²=65·7%) and two from high-income countries (summary RR=1·56; 95% CI 0·57, 4·26; I²=68·3%). Two studies assessed the effect of exclusive breast-feeding until 6 months (OR=0·91; 95% CI 0·61, 1·34 and OR=1·71; 95% CI 0·66, 4·47, respectively).


CONCLUSIONS
Our results suggest a protective effect of breast-feeding in economically less developed settings. However, further research is needed, with a finer assessment of the exposure to breast-feeding and careful control for confounding, before definite conclusions can be reached.
1Department of Clinical Epidemiology,Predictive Medicine and Public Health,University of Porto Medical School,Al. Prof. Hernâni Monteiro,4200-319,Porto,Portugal.
Helena
H
Carreira
1Department of Clinical Epidemiology,Predictive Medicine and Public Health,University of Porto Medical School,Al. Prof. Hernâni Monteiro,4200-319,Porto,Portugal.
Ana
A
Bastos
1Department of Clinical Epidemiology,Predictive Medicine and Public Health,University of Porto Medical School,Al. Prof. Hernâni Monteiro,4200-319,Porto,Portugal.
Bárbara
B
Peleteiro
1Department of Clinical Epidemiology,Predictive Medicine and Public Health,University of Porto Medical School,Al. Prof. Hernâni Monteiro,4200-319,Porto,Portugal.
Nuno
N
Lunet
D000293:Adolescent; D000818:Animals; D001942:Breast Feeding; D002648:Child; D002675:Child, Preschool; D003906:Developing Countries; D019317:Evidence-Based Medicine; D005759:Gastroenteritis / Q000453:epidemiology / Q000276:immunology / Q000382:microbiology / Q000517:prevention & control; D016481:Helicobacter Infections / Q000453:epidemiology / Q000276:immunology / Q000382:microbiology / Q000517:prevention & control*; D016480:Helicobacter pylori / Q000254:growth & development / Q000276:immunology*; D006801:Humans; D007112:Immunity, Maternally-Acquired; D015994:Incidence; D015995:Prevalence; D012307:Risk Factors
Adolescent; Breast-feeding; Child; Helicobacter pylori