Factors influencing the composition of the intestinal microbiota in early infancy

OBJECTIVE: The aim of this study was to examine the contribution of a broad range of external influences to the gut microbiotic composition in early infancy. METHODS: Fecal samples from 1032 infants at 1 month of age, who were recruited from the KOALA Birth Cohort Study in the Netherlands, were subjected to quantitative real-time polymerase chain reaction assays for the enumeration of bifidobacteria, Escherichia coli, Clostridium difficile, Bacteroides fragilis group, lactobacilli, and total bacterial counts. Information on potential determinants of the gut microbiotic composition was collected with repeated questionnaires. The associations between these factors and the selected gut bacteria were analyzed with univariate and multivariate analyses. RESULTS: Infants born through cesarean section had lower numbers of bifidobacteria and Bacteroides, whereas they were more often colonized with C difficile, compared with vaginally born infants. Exclusively formula-fed infants were more often colonized with E coli, C difficile, Bacteroides, and lactobacilli, compared with breastfed infants. Hospitalization and prematurity were associated with higher prevalence and counts of C difficile. Antibiotic use by the infant was associated with decreased numbers of bifidobacteria and Bacteroides. Infants with older siblings had slightly higher numbers of bifidobacteria, compared with infants without siblings. CONCLUSIONS: The most important determinants of the gut microbiotic composition in infants were the mode of delivery, type of infant feeding, gestational age, infant hospitalization, and antibiotic use by the infant. Term infants who were born vaginally at home and were breastfed exclusively seemed to have the most "beneficial" gut microbiota (highest numbers of bifidobacteria and lowest numbers of C difficile and E coli). AD - Department of Epidemiology, Nutrition and Toxicology Research Institute Maastricht, Maastricht University, PO Box 616, 6200 MD Maastricht, Netherlands. [email protected]

Gut microbiota composition and development of atopic manifestations in infancy: the KOALA birth cohort study

BACKGROUND AND AIMS: Perturbations in intestinal microbiota composition due to lifestyle changes may be involved in the development of atopic diseases. We examined gut microbiota composition in early infancy and the subsequent development of atopic manifestations and sensitisation. METHODS: The faeces of 957 infants aged 1 month and participating in the KOALA Birth Cohort Study were analysed using quantitative real-time PCR. Information on atopic symptoms (eczema, wheeze) and potential confounders was acquired through repeated questionnaires. Total and specific IgE were measured in venous blood samples collected during home visits when the infant was 2 years old. During these home visits a clinical diagnosis of atopic dermatitis was made according to the UK-Working Party criteria. RESULTS: The presence of Escherichia coli was associated with a higher risk of developing eczema (OR(adj) = 1.87; 95% CI 1.15 to 3.04), this risk being increased with increasing numbers of E coli (p(for trend) = 0.016). Infants colonised with Clostridium difficile were at higher risk of developing eczema (OR(adj) = 1.40; 95% CI 1.02 to 1.91), recurrent wheeze (OR(adj) = 1.75; 95% CI 1.09 to 2.80) and allergic sensitisation (OR(adj) = 1.54; 95% CI 1.02 to 2.31). Furthermore, the presence of C difficile was also associated with a higher risk of a diagnosis of atopic dermatitis during the home visit (OR(adj) = 1.73; 95% CI 1.08 to 2.78). CONCLUSION: This study demonstrates that differences in gut microbiota composition precede the development of atopy. Since E coli was only associated with eczema and C difficile was associated with all atopic outcomes, the underlying mechanisms explaining these association may be differen

Etiology of atopy in infancy: the KOALA Birth Cohort Study.

PG - 679-84 AB - The aim of the KOALA Birth Cohort Study in the Netherlands is to identify factors that influence the clinical expression of atopic disease with a main focus on lifestyle (e.g., anthroposophy, vaccinations, antibiotics, dietary habits, breastfeeding and breast milk composition, intestinal microflora composition, infections during the first year of life, and gene-environment interaction). The recruitment of pregnant women started in October 2000. First, participants with 'conventional lifestyles' (n = 2343) were retrieved from an ongoing prospective cohort study (n = 7020) on pregnancy-related pelvic girdle pain. In addition, pregnant women (n = 491) with 'alternative lifestyles' with regard to child rearing practices, dietary habits (organic, vegetarian), vaccination schemes and/or use of antibiotics, were recruited through organic food shops, anthroposophic doctors and midwives, Steiner schools, and dedicated magazines. All participants were enrolled between 14 and 18 wk of gestation and completed an intake questionnaire on family history of atopy and infant care intentions. Documentation of other relevant variables started in the pregnant mother and covered the first and third trimester as well as early childhood by repeated questionnaires at 14-18, 30, and 34 wk of gestation and 3, 7, 12, and 24 months post-partum. A subgroup of participants, including both conventional and alternative lifestyles, was asked to consent to maternal blood sampling, breast milk and a faecal sample of the infant at 1 month post-partum, capillary blood at age 1 yr, venous blood and observation of manifestation of atopic dermatitis during home visits at the age of 2 yr (using the UK working party criteria and the severity scoring of atopic dermatitis index), and buccal swabs for DNA isolation from child-parent trios. From the start, ethical approval and informed consent procedures included gene-environment interaction studies. Follow-up at 3 and 7 months post-partum was completed with high response rates (respectively 90% and 88% in the conventional group, and 97% and 97% in the alternative group). The home visits at 2 yr of age will be completed in 2005. Preliminary results show that we have succeeded in recruiting a large population with various lifestyle choices with a fairly large contrast with regard to dietary habits (including organic foods, vegetarian diet), vaccination schemes and/or use of antibiotics. We have also been able to collect a large number of faecal samples (n = 1176) and capillary blood samples at age 1 yr (n = 956). Furthermore, a large proportion of the participants have consented with genetic studies. Mid 2006 we expect to report our first results on the relationship between the various exposures in early life and childhood atopy. An outline of the focus and design of the KOALA Birth Cohort Study is presented. AD - Department of Epidemiology, Care and Public Health Research Institute (Caphri), Maastricht University, Maastricht, The Netherlands. [email protected]

General practitioners' contribution to the management of community-acquired pneumonia in the Netherlands: a retrospective analysis of primary care, hospital, and national mortality databases with individual data linkage.

Background: Community-acquired pneumonia (CAP) is an important cause of hospital admission and death, but the extent of the problem of CAP at the primary healthcare level is largely unknown. Aims: To investigate the contribution of general practitioners (GPs) to the management of patients with CAP in the Netherlands. Methods: The study population consisted of all people enlisted in a GP network. We obtained information on CAP episodes from GP electronic records (using ICPC code R81) during the years 2002–2009. CAP registrations were also obtained from national hospital discharge data (ICD-9 codes) and cause of death statistics (ICD-10 codes). The three registration systems were linked at the individual level. We used descriptive analyses to estimate the annual number of CAP episodes (i.e. defined as a CAP diagnosis within 30 days). Results: From 2002 to 2009 the mean annual size of the study population was 395,039. For this population, 3,700 (0.9%) CAP episodes per year were registered in at least one of the registration systems, 2,933 (79%) of which were in the GP system only. Recovery within 30 days occurred on average in 95% (2,791/2,933) of the CAP episodes annually registered by a GP, while 2.3% (67/2,933) of patients with a GP-registered CAP episode were admitted to hospital within 30 days and 1% (26/2,933) had a fatal outcome within 30 days. Conclusions: The vast majority of CAP episodes registered in the Netherlands are managed successfully at the GP level without hospitalisation. (aut.ref.