Michelle McKean

Lactobacillus casei abundance is associated with profound shifts in the infant gut microbiome.

Colonization of the infant gut by microorganisms over the first year of life is crucial for development of a balanced immune response. Early alterations in the gastrointestinal microbiota of neonates has been linked with subsequent development of asthma and atopy in older children. Here we describe high-resolution culture-independent analysis of stool samples from 6-month old infants fed daily supplements of Lactobacillus casei subsp. Rhamnosus (LGG) or placebo in a double-blind, randomized Trial of Infant Probiotic Supplementation (TIPS). Bacterial community composition was examined using a high-density microarray, the 16S rRNA PhyloChip, and the microbial assemblages of infants with either high or low LGG abundance were compared. Communities with high abundance of LGG exhibited promotion of phylogenetically clustered taxa including a number of other known probiotic species, and were significantly more even in their distribution of community members. Ecologically, these aspects are characteristic of communities that are more resistant to perturbation and outgrowth of pathogens. PhyloChip analysis also permitted identification of taxa negatively correlated with LGG abundance that have previously been associated with atopy, as well as those positively correlated that may prove useful alternative targets for investigation as alternative probiotic species. From these findings we hypothesize that a key mechanism for the protective effect of LGG supplementation on subsequent development of allergic disease is through promotion of a stable, even, and functionally redundant infant gastrointestinal community.

The Timing of Infant Food Introduction in Families With a History of Atopy

Objective. To describe the timing of introduction and type of food introduced to infants with a family history of atopy. Methods. We conducted a secondary analysis of foods introduced each month to an interventional birth cohort of 149 infants at risk for atopy. Results. Seven percent of infants received solid food prior to 4 months of age; 13% after 6 months of age. Hyperallergenic foods were introduced on average in the following order: wheat (8.7 months); eggs (11.2 months); soy (13.0 months); fish (13.4 months); peanut (20.2 months); tree nuts (21.8 months); and other seafood (21.8 months). Asian race (odds ratio 3.94; 95% CI 1.14-13.58) and maternal history of food allergy (odds ratio 3.86; 95% CI 1.29-11.56) were associated with late food introduction. Conclusion. Variation in timing of food introduction may reflect cultural preferences and/or previous experience with food allergy, as well as the ambiguous state of current recommendations.

Early Probiotic Supplementation for Eczema and Asthma Prevention: A Randomized Controlled Trial

In this randomized controlled trial, we examined the effect of early LGG infant supplementation in decreasing the risk of childhood eczema. OBJECTIVES: To determine if probiotic administration during the first 6 months of life decreases childhood asthma and eczema. METHODS: We conducted a randomized, double-blind controlled trial of Lactobacillus rhamnosus GG (LGG) supplementation on the cumulative incidence of eczema (primary end point) and asthma and rhinitis (secondary end points) in high-risk infants. For the first 6 months of life, intervention infants (n = 92) received a daily dose of 10 billion colony-forming units of LGG and 225 mg of inulin (Amerifit Brands, Cromwell, CT), and control infants (n = 92) received 325 mg of inulin alone. We used survival analysis methods to estimate disease incidences in the presence or absence of LGG and to estimate the efficacy of LGG in delaying or preventing these diseases. RESULTS: Infants were accrued over a 6-year period (median follow-up: 4.6 years; 95% retention rate at 2 years). At 2 years of age, the estimated cumulative incidence of eczema was 30.9% (95% confidence interval [CI], 21.4%–40.4%) in the control arm and 28.7% (95% CI, 19.4%–38.0%) in the LGG arm, for a hazard ratio of 0.95 (95% CI, 0.59–1.53) (log-rank P = .83). At 5 years of age, the cumulative incidence of asthma was 17.4% (95% CI, 7.6%–27.1%) in the control arm and 9.7% (95% CI, 2.7%–16.6%) in the LGG arm, for a hazard ratio of 0.88 (95% CI, 0.41–1.87) (log-rank P = .25). CONCLUSIONS: For high-risk infants, early LGG supplementation for the first 6 months of life does not appear to prevent the development of eczema or asthma at 2 years of age.

Delayed gut microbiota development in high-risk for asthma infants is temporarily modifiable by Lactobacillus supplementation

Gut microbiota dysbiosis and metabolic dysfunction in infancy precedes childhood atopy and asthma development. Here we examined gut microbiota maturation over the first year of life in infants at high risk for asthma (HR), and whether it is modifiable by early-life Lactobacillus supplementation. We performed a longitudinal comparison of stool samples collected from HR infants randomized to daily oral Lactobacillus rhamnosus GG (HRLGG) or placebo (HRP) for 6 months, and healthy (HC) infants. Meconium microbiota of HRP participants is distinct, follows a delayed developmental trajectory, and is primarily glycolytic and depleted of a range of anti-inflammatory lipids at 6 months of age. These deficits are partly rescued in HRLGG infants, but this effect was lost at 12 months of age, 6 months after cessation of supplementation. Thus we show that early-life gut microbial development is distinct, but plastic, in HR infants. Our findings offer a novel strategy for early-life preventative interventions.Gut microbial dysbiosis in infancy is associated with childhood atopy and the development of asthma. Here, the authors show that gut microbiota perturbation is evident in the very earliest stages of postnatal life, continues throughout infancy, and can be partially rescued by Lactobacillus supplementation in high-risk for asthma infants.

Higher Birth Weight Improves Rates of Exclusive Breastfeeding Through 3 Months

Background. Exclusive breastfeeding through 3 months is a Healthy People 2020 goal, yet most US infants who initiate breastfeeding receive formula before 3 months. The effect of birth weight on exclusive breastfeeding has not been previously studied. Methods. We analyzed data from a randomized trial of probiotics for healthy infants to determine the effect of birth weight and other predictors available at birth on any breastfeeding and exclusive breastfeeding through 3 months. We used backward stepwise logistic regression to examine the effect of maternal age, education, feeding plan, delivery method, and parity and infant birth weight and gestational age on the outcomes of any and exclusive breastfeeding through 3 months. Results. Birth weight was strongly associated with exclusive breastfeeding through 3 months (odds ratio = 6.23 [95% confidence interval = 2.27-17.1] per kilogram birth weight), adjusting for maternal college education and maternal plan to breastfeed exclusively. However, birth weight wa...

Television During Meals in the First 4 Years of Life

The development of children’s mealtime television (TV) habits has not been well studied. We assessed whether mealtime TV habits established in infancy will persist into early childhood. We analyzed data collected through parent surveys at birth and at 6-month intervals from a randomized controlled trial. We used t-tests, χ2 tests, and a multivariable logistic regression to determine if family characteristics were associated with mealtime TV. A McNemar test was used to assess whether mealtime TV exposure changed over time. College-educated fathers and families with an annual income >

Postpartum Depression: When Should Health Care Providers Identify Those at Risk?

50 000 were associated with less-frequent TV exposure during children’s mealtimes. It was found that 84% of children retained their level of exposure to TV during mealtimes from the first 24 months through 48 months of life. Clinicians should counsel families about mealtime TV use within the first 2 years of life because these habits seem to develop early and persist into at least early childhood.

Tu2018 The Developing Gastrointestinal Microbiota of Healthy Infants Over the First Year of Life

Maternal postpartum depression (PPD) has an impact on mothers and infants. The American Academy of Pediatrics recommends screening for PPD at well-child visits during the first 6 months. We conducted a secondary data analysis of depression screening data collected each month during months 1 to 12 postpartum for 152 mothers with an infant participating in a randomized controlled trial. We used descriptive statistics to describe the incidence and the cumulative incidence of a positive PPD screen during months 1 to 12 postpartum. The results indicate that the initial positive screen for PPD can occur any time during the first 12 months postpartum and 15% had their first positive screen between months 6 and 12. Additionally, positive PPD screens are consistently high throughout the first year postpartum with the highest rate of positive screens at 12 months postpartum (23%). Our data suggest that PPD screening through 12 months may be most beneficial for families.

Examining the hygiene hypothesis: The Trial of Infant Probiotic Supplementation

genic diversity (r=0.7478, p<0.0001) expanded significantly over the first year of life and microbial community composition was associated with age. We show that microbial communities present at birth are compositionally distinct, and that the bacterial burden of the initial inoculum does not influence the rate of phylogenic expansion (p=0.224). This rate of diversification varied across infants, most likely reflecting personal environmental exposures. Interpersonal variation in community composition was higher in younger infants and decreased considerably following introduction of solid foods at 6 months of age. Despite diversity accumulation with age, intra-individual community composition similarity was high across all time points sampled. In addition, a core community, defined as OTUs present in all samples from the same infant at 1 month through to 12 month of age was identified in each infant. These core communities consisted on average of 6.3% (2.0%-11.8%) of the total number of OTUs detected at 12 months, in an individual infant. No core microbiome was detected across all participants. This strongly suggests that personal environmental exposures begin to shape the microbial community shortly after birth and that though the complexity and diversity increase with infants age, each individual develops a personal microbiota of which the core constituents remain present across the first year of life. In conclusion this study highlights the heterogeneity within microbial assemblages found in healthy infants, strongly supporting the view that personal environmental exposures shortly after birth, much more than the initial microbial inoculum, influence gut microbiome development during this crucial period.