Contrasting microbiotas between Finnish and Estonian infants: Exposure to Acinetobacter may contribute to the allergy gap.

BACKGROUND: Allergic diseases are more common in Finland than in Estonia, which-according to the biodiversity hypothesis-could relate to differences in early microbial exposures. METHODS: We aimed at defining possible microbial perturbations preceding early atopic sensitization. Stool, nasal and skin samples of 6-month-old DIABIMMUNE study participants with HLA susceptibility to type 1 diabetes were collected. We compared microbiotas of sensitized (determined by specific IgE results at 18 months of age) and unsensitized Estonian and Finnish children. RESULTS: Sensitization was differentially targeted between populations, as egg-specific and birch pollen-specific IgE was more common in Finland. Microbial diversity and community composition also differed; the genus Acinetobacter was more abundant in Estonian skin and nasal samples. Particularly, the strain-level profile of Acinetobacter lwoffii was more diverse in Estonian samples. Early microbiota was not generally associated with later sensitization. Microbial composition tended to differ between children with or without IgE-related sensitization, but only in Finland. While land-use pattern (ie green areas vs. urban landscapes around the children's homes) was not associated with microbiota as a whole, it associated with the composition of the genus Acinetobacter. Breastfeeding affected gut microbial composition and seemed to protect from sensitization. CONCLUSIONS: In accordance with the biodiversity hypothesis, our results support disparate early exposure to environmental microbes between Finnish and Estonian children and suggest a significant role of the genus Acinetobacter in the allergy gap between the two populations. The significance of the observed differences for later allergic sensitization remains open.

Breastfeeding patterns of mothers with type 1 diabetes: results from an infant feeding trial.

BACKGROUND: Both the initiation and maintenance of breastfeeding have been reported to be negatively affected by maternal type 1 diabetes (T1D). The aim of this study was to prospectively examine the breastfeeding patterns among mothers with and without T1D participating in a large international randomized infant feeding trial (TRIGR). METHODS: Families with a member affected by T1D and with a newborn infant were invited into the study. Those who had HLA-conferred genetic susceptibility for T1D tested at birth with gestation > 35 weeks and were healthy were eligible to continue in the trial. Among the 2160 participating children, 1096 were born to women with T1D and 1064 to unaffected women. Information on infant feeding was acquired from the family by frequent prospective dietary interviews. RESULTS: Most (>90%) of the infants of mothers with and without T1D were initially breastfed. Breastfeeding rates declined more steeply among mothers with than without T1D being 50 and 72% at 6 months, respectively. Mothers with T1D were younger, less educated and delivered earlier and more often by caesarean section than other mothers (p < 0.01). After adjusting for all these factors associated with the termination of breastfeeding, there was no difference in the duration of breastfeeding among mothers with and without T1D. CONCLUSIONS: Maternal diabetes status per se was not associated with shorter breastfeeding. The lower duration of breastfeeding in mothers with T1D is largely explained by their more frequent caesarean sections, earlier delivery and lower age and education.