A newborn infant’s immune system needs to quickly learn how to tolerate beneficial bacteria and defend against opportunistic pathogens. The intestinal microbiota can influence the balance between proinflammatory and regulatory immune responses.¹ However, there are still unanswered questions as to how the immune system interacts with the microbiota.^2,3

Background: Although breastfeeding is touted as providing many health benefits to infants, some aspects of this relationship remain poorly understood.Methods: The Environmental Determinants of Diabetes in the Young (TEDDY) is a prospective longitudinal study that follows children from birth through childhood, and collects data on illness events, breastfeeding duration, and time to introduction of formula or foods at 3 month intervals up until 4 years of age and at 6 months intervals thereafter. Exclusive and non-exclusive breastfeeding is examined in relation to the 3-month odds of a respiratory or gastrointestinal infection for 6861 children between the ages of 3–18 months, and 5666 children up to the age of 4 years. Analysis was performed using logistic regression models with generalized estimating equation methodology. All models were adjusted for potential confounding variables.Results: At 3–6 months of age, breastfeeding was found to be inversely associated with the odds of respiratory infections with fever (OR = 0.82, 95% CI = 0.70–0.95), otitis media (OR = 0.76, 95% CI = 0.62–0.94), and infective gastroenteritis (OR = 0.55, 95% CI = 0.46–0.70), although the inverse association with respiratory illnesses was observed only for girls during the winter months. Between 6 and 18 months of age, breastfeeding within any 3 month period continued to be inversely associated with the odds of ear infection and infective gastroenteritis, and additionally with the odds of conjunctivitis, and laryngitis and tracheitis, over the same 3 month period within this age range. However, breastfeeding in this group was associated with increased reports of common cold. Duration of exclusive breastfeeding was inversely associated with the odds of otitis media up to 48 months of age (OR = 0.97, 95% CI = 0.95–0.99) after breastfeeding had stopped.Conclusions: This study demonstrates that breastfeeding can be protective against multiple respiratory and gastrointestinal acute illnesses in some children up to at least 6 months of age, with duration of exclusive breastfeeding being somewhat protective of otitis media even after breastfeeding has stopped.Trial registration: ClinicalTrials.gov Identifier:NCT00279318.Date of registration: January 17, 2006 (proactively registered).First Posted: January 19, 2006.

Objective: To study whether the dietary patterns of Finnish pregnant women are associated with their weight gain rate during pregnancy.Design: A validated 181-item FFQ was applied retrospectively to assess the diet during the eighth month of pregnancy, and maternal height and maternal weight at first and last antenatal visits were recalled. Information on sociodemographic characteristics, parity and smoking of the pregnant women was obtained by a structured questionnaire and from the Finnish Birth Registry. Principal components analysis was used to identify dietary patterns that described the diet of pregnant women based on their food consumption profile.Setting: Finland.Subjects: Subjects consisted of 3360 women who had newly delivered in 1997–2002 and whose baby carried human leucocyte antigen-conferred susceptibility to type 1 diabetes in two university hospital regions, Oulu and Tampere, in Finland.Results: Out of seven dietary patterns identified, the ‘fast food’ pattern was positively associated (β= 0·010,se= 0·003,P= 0·004) and the ‘alcohol and butter’ pattern was inversely associated (β= –0·010,se= 0·003,P< 0·0001) with weight gain rate (kg/week) during pregnancy after adjusting for potential dietary, perinatal and sociodemographic confounding factors. Both of the dietary pattern associations demonstrated dose dependency.Conclusions: Pregnant women should be guided to have a well-planned, balanced, healthy diet during pregnancy in order to avoid rapid gestational weight gain. The association between diet, health and maternal weight gain of the women who consumed alcohol during pregnancy should be studied further.

OBJECTIVE To examine duration of breastfeeding and timing of complementary foods and risk of islet autoimmunity (IA). RESEARCH DESIGN AND METHODS The TEDDY study prospectively follows 8,676 children with increased genetic risk of type 1 diabetes (T1D) in the U.S., Finland, Germany, and Sweden. This study included 7,563 children with at least 9 months of follow-up. Blood samples were collected every 3 months from birth to evaluate IA, defined as persistent, confirmed positive insulin autoantibodies (IAAs), glutamic acid decarboxylase, or insulinoma antigen-2. We examined the associations between diet and the risk of IA using Cox regression models adjusted for country, T1D family history, HLA genotype, sex, and early probiotic exposure. Additionally, we investigated martingale residuals and log-rank statistics to determine cut points for ages of dietary exposures. RESULTS Later introduction of gluten was associated with increased risk of any IA and IAA. The hazard ratios (HRs) for every 1-month delay in gluten introduction were 1.05 (95% CI 1.01, 1.10; P = 0.02) and 1.08 (95% CI 1.00, 1.16; P = 0.04), respectively. Martingale residual analysis suggested that the age at gluten introduction could be grouped as 9 months. The risk of IA associated with introducing gluten before 4 months of age was lower (HR 0.68; 95% CI 0.47, 0.99), and the risk of IA associated with introducing it later than at the age of 9 months was higher (HR 1.57; 95% CI 1.07, 2.31) than introduction between 4 and 9 months of age. CONCLUSIONS The timing of gluten-containing cereals and IA should be studied further.