The long-term effects of breastfeeding on asthma and atopic disease

Does Oxidative Stress Along with Dysbiosis Participate in the Pathogenesis of Asthma in the Obese?

The most important environmental factor that can play a key role in the development of asthma in the obese is overproduction of reactive oxygen species (ROS). The aim of the study was to examine changes in the concentration of oxidative stress parameters in the lungs, bronchoalveolar lavage (BAL) fluid and blood of mice in models of asthma or/and obesity caused by high-fat diet (HFD). The concentrations of 4-HNE and isoprostanes in the lungs of the animals were measured. BAL fluid levels of hydrogen peroxide were marked. Additionally, thiobarbituric acid reactive substances (TBARS) and ferric reducing ability of plasma (FRAP) were used as biomarkers of oxidative stress in the blood. Administration of lipoic acid (LA), a probiotic with standard-fat diet (SFD, 10% fat) and low-fat diet (LFD, 5% fat) significantly decreased the concentration of 4-HNE as compared to the OVA (ovalbumin) + HFD group (p < 0.05). Treatment with low-fat diet or LFD in combination with apocynin insignificantly decreased H₂O₂ values as compared to the OVA + HFD group. Supplementation of probiotic with SFD and LFD significantly decreased the concentration of TBARS as compared to the OVA + SFD and saline + HDF groups (p < 0.05). Significantly lower concentrations of TBARS were also observed in the LA plus LFD group (p < 0.05) as compared to the OVA + HFD group. Low-fat diet with probiotic significantly increased the concentration of FRAP as compared to the obese mice (p = 0.017). Treatment with LFD in combination with LA significantly increased FRAP values as compared to the obese and obese asthmatic mice (p < 0.001).

Exclusive breastfeeding for the first 3 months of life may reduce the risk of respiratory allergies and some asthma in children at the age of 6 years

AIM

We examined the associations between breastfeeding and respiratory allergies and types of asthma in American children.

METHODS

This longitudinal study used data from mother-infant pairs who took part in the Infant Feeding Practices Study II in 2005-2007 and the Year 6 Follow-Up Study in 2012. The mothers reported breastfeeding practices on a monthly basis for the first year of life, childhood asthma and allergies at age 6 years, and associated factors. Generalised linear models were used in statistical analyses.

RESULTS

Overall, 1177 mother-infant pairs were included in the sample. A third (32.9%) of the children were exclusively breastfed until the age of 3 months and by the age of 6 years 20.8% had been diagnosed with respiratory allergies and 11.3% with asthma. In the multivariable analyses, exclusive breastfeeding for 3 months was associated with a reduced relative risk of respiratory allergies of 0.77 at the age of 6 years. It also reduced the relative risk of asthma to 0.66, but only if the children did not have a family history of asthma.

CONCLUSION

This longitudinal study provided evidence that exclusive breastfeeding for the first 3 months may reduce the risk of respiratory allergies and asthma in children 6 years of age, but concerning asthma, statistical significance was reached only in children without a family predisposition to asthma.

Breastfeeding among Women with Rheumatoid Arthritis Compared with the General Population: Results from a Nationwide Prospective Cohort Study

Objective.

The World Health Organization recommends that infants be exclusively breastfed until the age of 6 months. The first objective was to compare breastfeeding frequencies and time of cessation between women with rheumatoid arthritis (RA) and the general population. The second objective was to identify why patients with RA discontinue breastfeeding.

Methods.

This study was embedded in the Pregnancy-induced Amelioration of Rheumatoid Arthritis (PARA) study, a nationwide prospective cohort study. From 2002 to 2008, a total of 249 pregnancies were followed from pregnancy until 6 months postpartum. Data on lactation and medication use were collected. Proportion tests were used to compare percentages of breastfeeding between the study population and the general/reference population.

Results.

At 4–6, 12, and 26 weeks postpartum, 43%, 26%, and 9% of the RA patients breastfed their offspring, respectively, compared with 63%, 46%, and 41% in the general population, respectively (p < 0.001). The main reason for women to discontinue breastfeeding was the restart of medication (n = 129, 57.8%). Nevertheless, more than 40% of these patients restarted medication that was considered compatible with breastfeeding.

Conclusion.

This large prospective study demonstrates that RA is associated with lower proportions of women breastfeeding their offspring and earlier cessation compared with the general population. A considerable number of patients discontinued breastfeeding so that they could start medication, even though many of the medications are considered safe to use during lactation. Using the results of this study, intervention strategies supporting RA patients who wish to breastfeed may be developed.

Obesity, Asthma, and the Microbiome

Obesity is a risk factor for asthma, but standard asthma drugs have reduced efficacy in the obese. Obesity alters the gastrointestinal microbial community structure. This change in structure contributes to some obesity-related conditions and also could be contributing to obesity-related asthma. Although currently unexplored, obesity may also be altering lung microbiota. Understanding the role of microbiota in obesity-related asthma could lead to novel treatments for these patients.

MicroRNAs in Breastmilk and the Lactating Breast: Potential Immunoprotectors and Developmental Regulators for the Infant and the Mother

Human milk (HM) is the optimal source of nutrition, protection and developmental programming for infants. It is species-specific and consists of various bioactive components, including microRNAs, small non-coding RNAs regulating gene expression at the post-transcriptional level. microRNAs are both intra- and extra-cellular and are present in body fluids of humans and animals. Of these body fluids, HM appears to be one of the richest sources of microRNA, which are highly conserved in its different fractions, with milk cells containing more microRNAs than milk lipids, followed by skim milk. Potential effects of exogenous food-derived microRNAs on gene expression have been demonstrated, together with the stability of milk-derived microRNAs in the gastrointestinal tract. Taken together, these strongly support the notion that milk microRNAs enter the systemic circulation of the HM fed infant and exert tissue-specific immunoprotective and developmental functions. This has initiated intensive research on the origin, fate and functional significance of milk microRNAs. Importantly, recent studies have provided evidence of endogenous synthesis of HM microRNA within the human lactating mammary epithelium. These findings will now form the basis for investigations of the role of microRNA in the epigenetic control of normal and aberrant mammary development, and particularly lactation performance.

The microbiome in asthma

The application of recently developed sensitive, specific, culture-independent tools for identification of microbes is transforming concepts of microbial ecology, including concepts of the relationships between the vast complex populations of microbes associated with ourselves and with states of health and disease. Although most work initially focused on the community of microbes (microbiome) in the gastrointestinal tract and its relationship to gastrointestinal disease, interest has expanded to include study of the relationships of the airway microbiome to asthma and its phenotypes and to the relationships between the gastrointestinal microbiome, development of immune function, and predisposition to allergic sensitization and asthma. Here we provide our perspective on the findings of studies of differences in the airway microbiome between asthmatic patients and healthy subjects and of studies of relationships between environmental microbiota, gut microbiota, immune function, and asthma development. In addition, we provide our perspective on how these findings suggest the broad outline of a rationale for approaches involving directed manipulation of the gut and airway microbiome for the treatment and prevention of allergic asthma.

Benefits, barriers and enablers of breastfeeding: factor analysis of population perceptions in Western Australia

OBJECTIVE

The objective of this study was to investigate knowledge and community perceptions of breastfeeding in Western Australia using a factor analysis approach.

METHODS

Data were pooled from five Nutrition Monitoring Survey Series which included information on breastfeeding from 4,802 Western Australian adults aged 18-64 years. Tetrachoric factor analysis was conducted for data reduction and significant associations identified using logistic, ordinal and poisson regression analyses.

RESULTS

Four factors were derived for benefits (it's natural, good nutrition, good for the baby, and convenience), barriers (breastfeeding problems, poor community acceptability, having to go back to work, and inconvenience) and for enablers (breastfeeding education, community support, family support and not having to work). As assessed by standardized odds ratios the most important covariates across benefit factors were: importance of breastfeeding (ORs range from 1.22-1.44), female gender (ORs range from 0.80 to 1.46), being able to give a time for how long a baby should be breastfed (ORs range from 0.96 to 1.27) and education (less than high school to university completion) (ORs range from 0.95 to 1.23); the most important covariate across barrier factors was being able to give a time for how long a baby should be breastfed (ORs range from 0.89 to 1.93); and the most important covariates across all enabling factors were education (ORs range from 1.14 to 1.32) and being able to give a time for how long a baby should be breastfed (ORs range from 1.17 to 1.42).

CONCLUSIONS

Being female, rating breastfeeding as important, believing that babies should be breastfed for a period of time and education accounted for most of the statistically significant associations. The differences between male and female perceptions require investigation particularly in relation to returning to work.

Cross-sectional epidemiological survey of asthma in Jinan, China

BACKGROUND AND OBJECTIVE

The prevalence and control of asthma in all ages are seldom known in Jinan, China. This study aims to determine the prevalence, related factors and control of asthma in populations of all ages in Jinan, China.

METHODS

A cross-sectional epidemiological questionnaire survey was performed with all members from approximately 4500 randomly selected families from 60 communities in the urban area and in 40 villages in the rural area. The completed questionnaires were focused on asthma, asthma-like respiratory symptoms and asthma control.

RESULTS

A total of 13,645 individuals were interviewed in the survey, and the number of effective questionnaires reached 13,419. The asthma prevalence of all ages in Jinan was 1.1%. Atopy, asthma family history, household size and age were independent factors related to asthma. The control of asthma in Jinan was suboptimal in a high proportion of patients and even worse in the rural area.

CONCLUSIONS

The asthma prevalence for all ages in Jinan was relatively low compared with that in western countries; however, local asthma control fell markedly short from the goals of the Global Initiative for Asthma (GINA) criteria for asthma management, which may be attributed to the poor adherence to GINA guidelines, especially the underuse of preventative medication of inhaled corticosteroids.

Primary prevention of allergic disease through nutritional interventions

With the rising prevalence of atopic disease, primary prevention may play a role in reducing its burden, especially in high-risk infants. With this in mind, the Adverse Reactions to Foods Committee of the American Academy of Allergy, Asthma & Immunology was charged with the task of developing recommendations for primary care physicians and specialists about the primary prevention of allergic disease through nutritional interventions according to current available literature and expert opinion. Recommendations that are supported by data are as follows. Avoidance diets during pregnancy and lactation are not recommended at this time, but more research is necessary for peanut. Exclusive breast-feeding for at least 4 and up to 6 months is endorsed. For high-risk infants who cannot be exclusively breast-fed, hydrolyzed formula appears to offer advantages to prevent allergic disease and cow's milk allergy. Complementary foods can be introduced between 4 and 6 months of age. Because no formal recommendations have been previously provided about how and when to introduce the main allergenic foods (cow's milk, egg, soy, wheat, peanut, tree nuts, fish, shellfish), these are now provided, and reasons to consider allergy consultation for development of a personalized plan for food introduction are also presented.

Does decline of lung function in wheezy infants justify the early start of controller medications?

OBJECTIVE

To compare lung function in wheezy infants, with risk factors of asthma and with some immunological parameters which may be useful as predictors of subsequent asthma.

METHODS

The data of 241 infants aged 5–36 mo, with recurrent wheeze (≥3 episodes of physician confirmed wheeze) prior to receiving inhaled corticosteroids or anti-leukotrine agents was retrospectively analyzed. They were subdivided into 2 subgroups; those with asthma risk factors (132 patients) and those without (109 patients) Also, 67 healthy, age and sex matched children without recurrent wheezes were taken as control group. Total serum IgE, eosinophilic percentage, tPTEF/tE (time to peak expiratory flow to total expiratory time), total respiratory system compliance (Crs) and resistance of the respiratory system (Rrs) was done for patients and control groups.

RESULTS

Wheezy infants had a significantly higher eosinophilic percentage and total serum IgE as well as a significantly lower pulmonary function parameters when compared to healthy controls. Wheezy infants with positive family history of asthma and those who had not been breast fed showed significant reduction in the mean values of tPTEF/tE and increased both eosinophilic percentage and total serum IgE. Crs was significantly decreased in wheezy infants with positive seasonal variations and those who had increased both eosinophilic percentage and total serum IgE. Rrs showed significant increase in wheezy infants with positive family history of atopy and those who had increased eosinophilic percentage and increased total serum IgE.

CONCLUSIONS

Lung function, eosinophilic percentage, total serum IgE and asthma risk factors could be used as predictors for ongoing wheeze in this subset of children.

Rising prevalence of asthma is sex-specific in a US farming population

BACKGROUND

Asthma prevalence is increasing worldwide in most populations, likely due to a combination of heritable factors and environmental changes. Curiously, however, some European farming populations are protected from asthma, which has been attributed to their traditional lifestyles and farming practices.

OBJECTIVE

We conducted population-based studies of asthma and atopy in the Hutterites of South Dakota, a communal farming population, to assess temporal trends in asthma and atopy prevalence and describe the risk factors for asthma.

METHODS

We studied 1325 Hutterites (ages 6-91 years) at 2 time points from 1996 to 1997 and from 2006 to 2009 by using asthma questionnaires, pulmonary function and methacholine bronchoprovocation tests, and measures of atopy.

RESULTS

The overall prevalence of asthma increased over the 10- to 13-year study period (7.5%-11.1%, P = .049), whereas the overall prevalence of atopy did not change (45.0%-44.8%, P = .95). Surprisingly, the rise in asthma was only among females (5.8%-11.2%, P = .02); the prevalence among males remained largely unchanged (9.4%-10.9%, P = .57). Atopy, which was not associated with asthma risk in 1996 to 1997, was the strongest risk factor for asthma among Hutterites studied in 2006 to 2009 (P = .003).

CONCLUSIONS

Asthma has increased over a 10- to 13-year period among Hutterite females and atopy has become a significant risk factor for asthma, suggesting a change in environmental exposures that are either sex limited or that elicit a sex-specific response.

Allergic diseases among very preterm infants according to nutrition after hospital discharge

To determine whether a cow's milk-based human milk fortifier (HMF) added to mother's milk while breastfeeding or a cow's milk-based preterm formula compared to exclusively mother's milk after hospital discharge, increases the incidence of developing allergic diseases among very preterm infants (VPI) during the first year of life. Of a cohort of 324 VPI (gestational age 24-32 wk), the exclusively breastfed VPI were shortly before discharge randomized to breastfeeding without fortification or supplementing with a fortifier. Those not breastfed were fed a preterm formula. The intervention period was from discharge until 4 months corrected age (CA). Follow-up was performed at 4 and 12 months CA including specific IgE to a panel of allergens at 4 months CA. The incidence during and prevalence at 12 months CA of recurrent wheezing (RW) was 39.2% and 32.7%, while atopic dermatitis (AD) was 18.0% and 12.1%, respectively. Predisposition to allergic disease increased the risk of developing AD (p=0.04) [OR 2.6 (95% CI 1.0-6.4)] and the risk of developing RW (p=0.02) [OR 2.7 (95% CI 1.2-6.3)]. Boys had an increased risk of developing RW (p=0.003) [OR 3.1 (95% CI 1.5-6.5)]. No difference was found between nutrition groups. None developed food allergy. Compared to exclusively breastfed, VPI supplemented with HMF or fed exclusively a preterm formula for 4 months did not have an increased risk of developing allergic diseases during the first year of life.

Characterization of immunocompetent cells in human milk of Han Chinese

Immunocompetent cells in colostrum and mature breast milk (42 days after delivery) of 64 Chinese females of Han ethnic background were characterized. The total cell numbers in colostrum and mature breast milk were 593 ± 205 × 10(6)/L and 1.74 ± 0.97 × 10(6)/L, respectively. NK cell is the predominant lymphocyte subtype (12.69%). T cells in colostrum express CD40L and CD25 without stimulation, indicating memory T cells in nature. The CD45RA( +)CD45RO(+) subsets of CD4(+) T cells are present in both colostrum and mature human milk. The percentage of NK cells and the absolute number of CD4(+)CD45RO(+) T cells in colostrum of atopic mothers were significantly lower than those of mothers without atopy (P = .006 and .026, respectively). The absolute numbers of CD4( +) T lymphocytes and their expression of CD40L were significantly reduced in breast milk of mothers who had undergone cesarean section versus vaginal delivery (P < .05), indicating that atopy and cesarean delivery are associated with the phenotypes of lymphocytes in colostrum.

Overweight, asthma symptoms, atopy and pulmonary function in children of 4-12 years of age: findings from the SCAALA cohort in Salvador, Bahia, Brazil

OBJECTIVE

To evaluate the association between overweight and the occurrence of asthma and atopy in a cohort of children of 4-12 years of age living in the city of Salvador in 2005.

DESIGN

Cross-sectional study nested in a cohort.

SETTING

The metropolitan region of Salvador, Bahia, Brazil.

SUBJECTS

The study included 1129 children of 4-12 years age who presented complete information on the variables used here. Skin tests for allergy, spirometry, faecal parasitology, serum IgE and anthropometric surveys were conducted. Poisson's multivariate regression was adopted.

RESULTS

Wheezing was found in 29·1% and asthma in 22·8% of children, both conditions being more common in those under 6 years of age and 34% more common in overweight children (prevalence ratio (PR) = 1·34; 95% CI 1·07, 1·67) following adjustment. The ratio between forced expiratory volume in 1s and forced vital capacity was associated with overweight (PR = 1·35; 95% CI 1·11, 1·61). No statistically significant association was found between overweight and allergen-specific IgE or with wheezing.

CONCLUSIONS

These results are in agreement with the hypothesis that overweight is associated with asthma and pulmonary function, even following adjustment for intervening variables known to be associated with the pathogeny of asthma.

Risk factors and asthma phenotypes in children and adults with seasonal allergic rhinitis

BACKGROUND

There are few data on asthma risk factors and phenotypes in patients with seasonal allergic rhinitis (SAR).

METHODS

Thirty-three children (mean age, 8.27 ± 1.77 years) and 82 adults (mean age, 34.12 ± 10.59 years) with SAR were evaluated for asthma (history, reversibility of bronchial obstruction, increased inhaled nitric oxide). The following asthma risk factors were considered in the multiple regression analysis: male sex, family history of asthma, breastfeeding < 2 months, passive/active smoking, obesity, pets/molds exposure, high total serum immunoglobulin E (IgE), polysensitization (sensitized to 3 seasonal pollens with different structure), mixed sensitization (seasonal and perennial allergens), severe rhinitis (according to the Allergic Rhinitis and its Impact on Asthma guidelines), and lack of allergen-specific immunotherapy (SIT) for rhinitis preceding asthma diagnosis. Asthma phenotypes were characterized using the k-means clustering (silhouette method for cluster validation).

RESULTS

Asthma was diagnosed in 22 (66.7%) children and in 57 (69.5%) adults with SAR. Independent risk factors for asthma were lack of SIT preceding asthma diagnosis, both for children (P = 0.008132) and adults (P = 0.000017), and mixed sensitization for children (P = 0.035694). Asthma phenotypes identified in children according to the associated risk factors were: breastfeeding < 2 months and severe rhinitis in 16 (63.6%) patients; male, polysensitized, and severe rhinitis in 8 (36.4%) patients. Asthma phenotypes in adults were: polysensitization and severe rhinitis in 30 (52.6%) patients; male, exposure to pets, and severe rhinitis in 11 (19.3%) patients; and high total serum IgE and polysensitization in 16 (28.1%) patients.

CONCLUSION

Lack of SIT is an independent risk factor for asthma both in children and adults with SAR, whereas polysensitization is a risk factor only for children. The dominant asthma phenotype in children with SAR is breastfeeding < 2 months and severe rhinitis. In adults with SAR, the dominant asthma phenotype is polysensitization and severe rhinitis.

microRNA as a new immune-regulatory agent in breast milk

Background

Breast milk is a complex liquid that provides nutrition to the infant and facilitates the maturation of the infant's immune system. Recent studies indicated that microRNA (miRNA) exists in human body fluid. Because miRNAs are known to regulate various immune systems, we hypothesized that human breast milk contains miRNAs that may be important for the development of the infant's immune system.

Findings

We profiled miRNA expression in human breast milk and detected high expression levels of immune-related miRNAs in the first 6 months of lactation. Furthermore, these miRNA molecules are stable even in very acidic conditions, indicating that breast milk allows dietary intake of miRNAs by infants.

Conclusions

Our findings provide new insight into how breast milk can modulate the development of the infant's immune system. This study suggests the transfer of genetic material as miRNA from human to human occurs by means other than through sexual reproduction.

Clinical practice: Breastfeeding and the prevention of allergy

The increase in allergic disease prevalence has led to heightened interest in the factors determining allergy risk, fueled by the hope that by influencing these factors one could reduce the prevalence of allergic conditions. The most important modifiable risk factors for allergy are maternal smoking behaviour and the type of feeding. A smoke-free environment for the child (to be), exclusive breastfeeding for 4-6 months and the postponement of supplementary feeding (solids) until 4 months of age are the main measures considered effective. There is no place for restricted diets during pregnancy or lactation. Although meta-analyses suggest that hypoallergenic formula after weaning from breastfeeding grants protection against the development of allergic disease, the evidence is limited and weak. Moreover, all current feeding measures aiming at allergy prevention fail to show effects on allergic manifestations later in life, such as asthma. In conclusion, the allergy preventive effect of dietary interventions in infancy is limited. Counselling of future parents on allergy prevention should pay attention to these limitations.