Intestinal microbiota composition after antibiotic treatment in early life: the INCA study.

BACKGROUND: The acquisition and development of infant gut microbiota can be influenced by numerous factors, of which early antibiotic treatment is an important one. However, studies on the effects of antibiotic treatment in early life on clinical outcomes and establishment and development of the gut microbiota of term infants are limited. Disturbed microbiota composition is hypothesized to be an underlying mechanism of an aberrant development of the immune system. This study aims to investigate the potential clinical and microbial consequences of empiric antibiotic use in early life. METHODS/DESIGN: 450 term born infants, of whom 150 are exposed to antibiotic treatment in early life and 300 are not (control group), are included in this observational cohort study with a one-year follow-up. Clinical outcomes, including coughing, wheezing, fever >38 °C, runny nose, glue ear, rash, diarrhea and >3 crying hours a day, are recorded daily by parents and examined by previously defined doctor's diagnosis. A blood sample is taken at closure to investigate the infant's vaccination response and sensitization for food and inhalant allergens. Fecal samples are obtained at eight time points during the first year of life. Potential differences in microbial profiles of infants treated with antibiotics versus healthy controls will be determined by use of 16S-23S rRNA gene analysis (IS-pro). Microbiota composition will be described by means of abundance, diversity and (dis)similarity. Diversity is calculated using the Shannon index. Dissimilarities between samples are calculated as the cosine distance between each pair of samples and analyzed with principal coordinate analysis. Clinical variables and possible associations are assessed by appropriate statistics. DISCUSSION: Both clinical quantitative and qualitative microbial effects of antibiotic treatment in early life may be demonstrated. These findings can be important, since there is evidence that manipulation of the infant microbiota by using pre- or probiotics can restore the ecological balance of the microbiota and may mitigate potential negative effects on the developing immune system, when use of antibiotics cannot be avoided. TRIAL REGISTRATION: ClinicalTrials.gov NCT02536560. Registered 28 August 2015.

Probiotic supplementation influences faecal short chain fatty acids in infants at high risk for eczema.

The composition of the gut microbiota plays a role in the development of allergies. Based on the immunomodulating capacities of bacteria, various studies have investigated the potential role for probiotics in the prevention of childhood eczema. In a previous study we have shown that significantly less children developed eczema after probiotic supplementation (Bifidobacterium bifidum W23, Bifidobacterium animalis subsp. lactis W52 and Lactococcus lactis W58, Ecologic(®)Panda) at three months of age as compared to controls. Here, metabolites in faecal samples of these 3-month old children were measured by (1)H-nuclear magnetic resonance to investigate possible gut metabolic alterations. Lower amounts of short-chain fatty acids (SCFAs), succinate, phenylalanine and alanine were found in faecal samples of children later developing eczema, whereas the amounts of glucose, galactose, lactate and lactose were higher compared to the children not developing eczema. Although these differences were already present at the age of 3 months, eczema did not develop in the majority of children before the age of 1 year. Supplementation of multispecies probiotics seems to induce higher levels of lactate and SCFAs, and lower levels of lactose and succinate when compared with the placebo group. This might explain the temporary preventive effect of probiotics on the development of eczema. These results highlight the role bacterial metabolites may play in development of the immune system, even before clinical manifestations of allergic disease arise.

Long Term Development of Gut Microbiota Composition in Atopic Children: Impact of Probiotics.

INTRODUCTION: Imbalance of the human gut microbiota in early childhood is suggested as a risk factor for immune-mediated disorders such as allergies. With the objective to modulate the intestinal microbiota, probiotic supplementation during infancy has been used for prevention of allergic diseases in infants, with variable success. However, not much is known about the long-term consequences of neonatal use of probiotics on the microbiota composition. The aim of this study was to assess the composition and microbial diversity in stool samples of infants at high-risk for atopic disease, from birth onwards to six years of age, who were treated with probiotics or placebo during the first year of life. METHODS: In a double-blind, randomized, placebo-controlled trial, a probiotic mixture consisting of B. bifidum W23, B. lactis W52 and Lc. Lactis W58 (Ecologic® Panda) was administered to pregnant women during the last 6 weeks of pregnancy and to their offspring during the first year of life. During follow-up, faecal samples were collected from 99 children over a 6-year period with the following time points: first week, second week, first month, three months, first year, eighteen months, two years and six years. Bacterial profiling was performed by IS-pro. Differences in bacterial abundance and diversity were assessed by conventional statistics. RESULTS: The presence of the supplemented probiotic strains in faecal samples was confirmed, and the probiotic strains had a higher abundance and prevalence in the probiotic group during supplementation. Only minor and short term differences in composition of microbiota were found between the probiotic and placebo group and between children with or without atopy. The diversity of Bacteroidetes was significantly higher after two weeks in the placebo group, and at the age of two years atopic children had a significantly higher Proteobacteria diversity (p < 0.05). Gut microbiota development continued between two and six years, whereby microbiota composition at phylum level evolved more and more towards an adult-like configuration. CONCLUSION: Perinatal supplementation with Ecologic® Panda, to children at high-risk for atopic disease, had minor effects on gut microbiota composition during the supplementation period. No long lasting differences were identified. Regardless of intervention or atopic disease status, children had a shared microbiota development over time determined by age that continued to develop between two and six years.

In vitro assessment of the immunomodulatory effects of multispecies probiotic formulations for management of allergic diseases.

Modulation of the composition of the intestinal microbiota with probiotics could possibly offer a way of prevention or management of allergic diseases. The objective of this study was to determine the immunomodulating effects of various multispecies probiotic combinations in vitro, as preamble to application in vivo. Multispecies probiotic combinations were formulated and tested for their effects on in vitro cytokine production by human mononuclear cells and were compared to products that already have shown beneficial effects in vivo. All 4 tested combinations of probiotics showed a 40-71% decrease of Th2 cytokine production (IL-4, IL-5, and IL-13) and a variable increase of Th1 (IFN-γ) and Treg cytokine (IL-10) production compared to the medium. A specific probiotic mixture that contained Bifidobacterium breve W25, Bifidobacterium lactis ATCC SD 5219, B. lactis ATCC SD 5220, Lactobacillus plantarum W62, Lactobacillus salivarius W57 and Lactococcus lactis W19 was superior in its stimulating effect on IL-10 production (significant better than the other tested combinations; P=0.001). Modulation of in vitro cytokine production profiles can be used to differentiate between selected probiotic formulations for their immunomodulatory properties. In the future it should be demonstrated whether the immunomodulatory capacities from the multispecies probiotic formulation with the desired profile will be effective in vivo (in adolescents, followed by application in children).