title: Breast milk and gut microbiota in African mothers and infants from an area of high HIV prevalence.
abstract: BACKGROUND
  Human milk and infant gut microbiota are essential for the immune system maturation and protection against infections. There is scarce information on the microbiological composition of breast milk in general, and none from developing countries. The objective of the study was to characterize the breast milk and gut microbiota from mothers and infants from southern Mozambique, where infections and breastfeeding are prevalent.
  
  
  METHODS
  A community-based study was undertaken among 121 pairs of women and infants. Breast milk and infant's faeces were analyzed by bacterial culture and molecular methods. Breast milk samples were screened for HIV RNA by RT-PCR.
  
  
  RESULTS
  The most frequent bacterial groups isolated by culture media in breast milk were Staphylococci (96.4%), Streptococci (92.7%) and Lactobacilli (56.4%). HIV RNA was detected in 24% of the samples. Staphylococcus hominis, S. aureus, and S.parasanguis were more frequently isolated in infants ≤14 days of life. Women on exclusive breastfeeding presented higher proportion of S. parasanguis in breast milk than those on mixed infant feeding (36.4% versus 11.1%, p = 0.035). Bacterial diversity (mean number of bacterial species isolated by sample: 10.4 versus 8.5; p = 0.004) and the frequency of Lactobacillus spp (75.9% versus 36%, p = 0.003) were higher in the specimens with HIV RNA than in those without it. The main bacterial groups found in infant's faeces were Bifidobacterium, Streptococci and Enterococci.
  
  
  CONCLUSIONS
  Women with HIV RNA in breast milk had a different pattern of microbiological composition, suggesting specific immunopathological phenomena in HIV-infected women. Both breast milk and faecal microbiota composition varied with lactation period, which might be related to changes in the type of feeding over time and/or in the milk's biochemical characteristics. These findings provide insights into interactions between commensal bacteria and HIV infection in human milk and the role of these bacteria in mucosal protection against infections in breastfed infants.
authors.affiliation: Barcelona Centre for International Heath Research (CRESIB, Hospital Clínic -Universitat de Barcelona), Barcelona, Spain ; Manhiça Health Research Centre (CISM), Maputo, Mozambique.
authors.forename: Raquel
authors.initials: R
authors.lastname: González
authors.forename: Antonio
authors.initials: A
authors.lastname: Maldonado
authors.forename: Virginia
authors.initials: V
authors.lastname: Martín
authors.forename: Inácio
authors.initials: I
authors.lastname: Mandomando
authors.forename: Victoria
authors.initials: V
authors.lastname: Fumadó
authors.forename: Karin J
authors.initials: KJ
authors.lastname: Metzner
authors.forename: Charfudin
authors.initials: C
authors.lastname: Sacoor
authors.forename: Leónides
authors.initials: L
authors.lastname: Fernández
authors.forename: Eusébio
authors.initials: E
authors.lastname: Macete
authors.forename: Pedro L
authors.initials: PL
authors.lastname: Alonso
authors.forename: Juan M
authors.initials: JM
authors.lastname: Rodríguez
authors.forename: Clara
authors.initials: C
authors.lastname: Menendez
mesh_terms: D000293:Adolescent; D000328:Adult; D001419:Bacteria / Q000145:classification / Q000235:genetics; D044383:Black People; D060085:Coinfection; D003430:Cross-Sectional Studies; D005243:Feces / Q000382:microbiology; D005260:Female; D041981:Gastrointestinal Tract / Q000382:microbiology*; D015658:HIV Infections / Q000453:epidemiology; D006801:Humans; D007223:Infant; D007774:Lactation; D064307:Microbiota; D008875:Middle Aged; D008895:Milk, Human / Q000382:microbiology* / Q000821:virology; D009035:Mothers; D015995:Prevalence; D055815:Young Adult