Dietary Interventions and Nutritional Factors in the Prevention of Pediatric Asthma

Pre-asthma: a useful concept for prevention and disease-modification? A EUFOREA paper. Part 1-allergic asthma

Asthma, which affects some 300 million people worldwide and caused 455,000 deaths in 2019, is a significant burden to suffers and to society. It is the most common chronic disease in children and represents one of the major causes for years lived with disability. Significant efforts are made by organizations such as WHO in improving the diagnosis, treatment and monitoring of asthma. However asthma prevention has been less studied. Currently there is a concept of pre- diabetes which allows a reduction in full blown diabetes if diet and exercise are undertaken. Similar predictive states are found in Alzheimer's and Parkinson's diseases. In this paper we explore the possibilities for asthma prevention, both at population level and also investigate the possibility of defining a state of pre-asthma, in which intensive treatment could reduce progression to asthma. Since asthma is a heterogeneous condition, this paper is concerned with allergic asthma. A subsequent one will deal with late onset eosinophilic asthma.

Self-reported prevalence of asthma and its associated factors among adult rural population in Bangladesh: a cross-sectional study using WHO PEN protocol

OBJECTIVE

For over a decade, the prevalence of asthma remained unchanged at around 7% in Bangladesh. Although asthma causes significant morbidity among both children and adults, updates on epidemiological data are limited on the prevalence in Bangladesh. This study attempted to determine the prevalence of asthma, and its modifiable and non-modifiable lifestyle predictors in a rural population of Bangladesh.

METHOD

This study was part of a cross-sectional study that applied the WHO Package of Essential Noncommunicable Disease Interventions via census in a rural area of Bangladesh, where self-reported data on asthma were recorded. Data on anthropometric measurement, sociodemographic characteristics and behavioural risk factors were collected following the standard protocol described in the WHO STEP-wise approach to surveillance (STEPS) questionnaire. Analysis included descriptive statistics to assess the prevalence of asthma and its risk factors, and binary logistic regression to determine contributing factors.

RESULT

The overall prevalence of asthma was 4.2%. Asthma was predominant among people above 60 years (8.4%). Higher asthma was noted among males (4.6%), self-employed (5.1%), with a family history of asthma (9.1%), with comorbidities besides asthma (7.8%) and underweight (6.0%) compared with their counterparts. The OR of having asthma was 1.89, 1.93, 1.32, 1.50, 2.60, 0.67, 0.67 and 0.78 if a respondent was 45 years old or more, married, underweight, ever smoker, with a family history of asthma, housewife, employed and consumed red meat, respectively, while considering all other variables constant, compared with their counterparts.

CONCLUSION

The study emphasised asthma to be a public health concern in Bangladesh, although it seems to have decreased over the last decade. Among others, red meat intake and nutritional status were strongly associated with asthma, and the linkage among these is still a grey area that needs further exploration.

Breast feeding, obesity, and asthma association: clinical and molecular views

Asthma is a chronic condition that affects children worldwide. Accumulating number of studies reported that the prevalence of pediatric obesity and asthma might be altered through breastfeeding. It has been proposed that Leptin, which exists in human milk, is oppositely associated with weight increase in newborns. It may also influence peripheral immune system by promoting TH1 responses and suppressing TH2 cytokines. Leptin influences body weight and immune responses through complex signaling pathways at molecular level. Although previous studies provide explanations for the protective role of breastfeeding against both obesity and asthma, other factors such as duration of breastfeeding, parental, and prenatal factors may confound this relationship which requires further research.

Homeostatic activation of aryl hydrocarbon receptor by dietary ligands dampens cutaneous allergic responses by controlling Langerhans cells migration

Dietary compounds can affect the development of inflammatory responses at distant sites. However, the mechanisms involved remain incompletely understood. Here, we addressed the influence on allergic responses of dietary agonists of aryl hydrocarbon receptor (AhR). In cutaneous papain-induced allergy, we found that lack of dietary AhR ligands exacerbates allergic responses. This phenomenon was tissue-specific as airway allergy was unaffected by the diet. In addition, lack of dietary AhR ligands worsened asthma-like allergy in a model of 'atopic march.' Mice deprived of dietary AhR ligands displayed impaired Langerhans cell migration, leading to exaggerated T cell responses. Mechanistically, dietary AhR ligands regulated the inflammatory profile of epidermal cells, without affecting barrier function. In particular, we evidenced TGF-β hyperproduction in the skin of mice deprived of dietary AhR ligands, explaining Langerhans cell retention. Our work identifies an essential role for homeostatic activation of AhR by dietary ligands in the dampening of cutaneous allergic responses and uncovers the importance of the gut-skin axis in the development of allergic diseases.

The Use of Prebiotics from Pregnancy and Its Complications: Health for Mother and Offspring—A Narrative Review

Pregnancy involves a metabolic reprogramming that includes changes in the gut microbiota composition in women. Evidence shows that maternal dysbiosis is linked to neonatal dysbiosis, and this factor can determine health status in adulthood. Although there is little literature available on this topic, high heterogeneity is a limitation when examining nutritional interventions. Information has been gathered to contrast the benefits of prebiotic usage, specifically in pregnancy, in its possible complications and in newborns’ gut microbiota development. The objective pursued in this brief narrative review is to provide a clear summary of relevant content when searching with regard to the use of prebiotics in pregnancy, the effects in prenatal and postnatal periods, and to help in clinical decision-making in pregnancy management and lactation. A search has found that the nutritional status of the pregnant mother is key for the earliest microbial colonization in newborns, and thus intervention programs from pregnancy could assure better outcomes in both the mother and offspring. In this sense, prebiotics (administered to mothers who breastfeed or provided in formula milk) are feasible and cost-effective elements that can prevent allergies, colic, and other maladies in newborns.

Mendelian randomization study shows a causal effect of asthma on epilepsy risk

Objective

The relationship between asthma and epilepsy in observational studies is controversial. The purpose of this Mendelian randomization (MR) study is to investigate whether asthma causally contributes to epilepsy susceptibility.

Methods

Independent genetic variants strongly (P<5E-08) associated with asthma were from a recent meta-analysis of genome-wide association studies on 408,442 participants. Two independent summary statistics of epilepsy obtained from the International League Against Epilepsy Consortium (ILAEC, Ncases=15,212, and Ncontrols=29,677) and FinnGen Consortium (Ncases=6,260 and Ncontrols=176,107) were used in the discovery and replication stage, respectively. Several sensitivity analyses and heterogeneity analyses were further conducted to assess the stability of the estimates.

Results

Using the inverse-variance weighted approach, genetic predisposition to asthma was associated with an elevated risk of epilepsy in the discovery stage (ILAEC: odds ratio [OR]=1.112, 95% confidence intervals [CI]= 1.023-1.209, P = 0.012), but not verified in the replication stage (FinnGen: OR=1.021, 95%CI= 0.896-1.163, P =0.753). However, a further meta-analysis of both ILAEC and FinnGen showed a similar result (OR=1.085, 95% CI: 1.012-1.164, P = 0.022). There were no causal associations between the age onset of asthma and epilepsy. Sensitivity analyses yielded consistent causal estimates.

Conclusion

The present MR study suggests that asthma is associated with an increased risk of epilepsy independent of the age onset of asthma. Further studies are warranted to explain the underlying mechanisms of this association.

Hydrolysierte Säuglingsnahrung für die Allergieprävention – wissenschaftliche Evidenz und Empfehlungen für die Praxis

Hintergrund

Laut S3-Leitlinie „Allergieprävention“ (Update 2021) soll bei nicht (voll) gestillten Säuglingen mit erhöhtem Allergierisiko geprüft werden, ob eine Säuglingsnahrung mit nachgewiesener allergiepräventiver Wirksamkeit verfügbar ist. Einige Hersteller bewerben ihre Produkte entsprechend.

Ziel der Arbeit

Der Artikel gibt einen Überblick über die wissenschaftliche Evidenz und internationale Empfehlungen zum Einsatz von hydrolysierter Säuglingsnahrung (sog. hypoallergene [HA-]Nahrung) zur Prävention von atopischen Erkrankungen.

Materialien und Methoden

In medizinischen Datenbanken wurde eine Literaturrecherche (Zeitraum: 2016–2021) zum Nutzen von hydrolysierten Säuglingsnahrungen für die Allergieprävention bei Risikokindern und zu entsprechenden internationalen Leitlinien durchgeführt. Auf dieser Basis wurden die aktuelle Empfehlung der deutschen S3-Leitlinie sowie die Produkte auf dem deutschen Markt eingeordnet.

Ergebnisse

Es gibt keine hinreichenden Belege für einen generellen allergiepräventiven Nutzen von Säuglingsnahrungen mit Proteinhydrolysat bei Säuglingen mit erhöhtem Allergierisiko. Die GINI-Interventionsstudie deutet darauf hin, dass eine der eingesetzten Hydrolysatnahrungen zur Prävention atopischer Dermatitis bei Risikokindern wirksam gewesen sein könnte. Die Ergebnisse können aber, auch angesichts methodischer Schwächen, nicht als alleinige Basis für eine allgemeine Empfehlung zur Verwendung von HA-Nahrung herangezogen werden. Internationale Fachgesellschaften sprechen sich seit einigen Jahren eher gegen eine solche Empfehlung aus.

Diskussion

Für die derzeit in Deutschland vermarkteten Säuglingsnahrungen auf Basis von partiell hydrolysiertem Protein fehlen Wirksamkeitsbelege. Sie können daher nicht zur Allergieprävention empfohlen werden.

Primary Prevention of Pediatric Asthma through Nutritional Interventions

Asthma is the most common chronic non-communicable disease in children, the pathogenesis of which involves several factors. The increasing burden of asthma worldwide has emphasized the need to identify the modifiable factors associated with the development of the disease. Recent research has focused on the relationship between dietary factors during the first 1000 days of life (including pregnancy)—when the immune system is particularly vulnerable to exogenous interferences—and allergic outcomes in children. Specific nutrients have been analyzed as potential targets for the prevention of childhood wheeze and asthma. Recent randomized controlled trials show that vitamin D supplementation during pregnancy, using higher doses than currently recommended, may be protective against early childhood wheezing but not school-age asthma. Omega-3 fatty acid supplementation during pregnancy and infancy may be associated with a reduced risk of childhood wheeze, although the evidence is conflicting. Data from observational studies suggest that some dietary patterns during pregnancy and infancy might also influence the risk of childhood asthma. However, the quality of the available evidence is insufficient to allow recommendations regarding dietary changes for the prevention of pediatric asthma. This review outlines the available high-quality evidence on the role of prenatal and perinatal nutritional interventions for the primary prevention of asthma in children and attempts to address unmet areas for future research in pediatric asthma prevention.

Role of Breathing Exercises in Asthma-Yoga and Pranayama

Asthma is a chronic airway inflammatory disease that results from a complex interplay of genetic, environmental, and lifestyle factors. There is no cure for asthma, and the management is usually as per published guidelines. As in many chronic diseases conditions, various alternative or complimentary therapies have been tried. Of these, yoga and pranayama have gained wider attention in recent years. While the term yoga is a complex term encompassing eight limbs as per Patamjai in the yoga sutras, in simple terms, yoga is described as a combination of 'asana' (physical exercises) and 'pranayama' (breathing exercise). The term "asthma" has been derived from the Greek word "panting,", which indicates a rapid and shallow breathing. The main aim of yoga and pranayama in asthma is to synchronize and control breathing, thus decreasing hyperventilation. Besides this, they also decrease the stress/strain/anxiety, change in behavior, boost immunity, and improve strength/endurance of respiratory muscles that are helpful in any subject with asthma. There have been a good number of studies including clinical trials in children with asthma that have found some beneficial effects. In the present review, the physiology of yoga and pranayama, rationale for their use in children with asthma along with a summary of various studies conducted till date, have been discussed. These are followed by recommendations regarding their incorporation in the standard of care of children with asthma.

Increased food diversity in the first year of life is inversely associated with allergic outcomes in the second year

BACKGROUND

The evidence on the relationship between diet diversity in early life and allergic outcomes was few and inconsistent. We sought to determine the association of food diversity in the first year of life with allergic outcomes in the second year.

METHODS

Two thousand two hundred fifty-one mother-infant pairs from Tongji Maternal and Child Health Cohort (TMCHC) were involved in the study. Information on complementary foods introduction was obtained by telephone interview at 6- and 12-month postpartum follow-up. Any doctor-diagnosed allergic diseases in the second year were recorded at 2-year postpartum follow-up. Food allergies in infancy were assessed and self-reported by mothers at each postpartum follow-up. Multivariable logistic regression was used to examine the effect of food diversity at 6 and 12 months of age on later allergic diseases and food allergy.

RESULTS

A total of 135 (6.0%) infants reported allergic diseases at between 1 and 2 years of age. Independent of food allergy history of infants and other potential confounders, less food diversity at 6 months of age was associated with increased risk of later allergic diseases (OR 2.17, 95% CI 1.04-4.50 for 0 vs. 3-6 food groups). By 12 months of age, significant inverse associations with later allergic diseases (OR 2.35, 95% CI 1.03-5.32 for 1-5 vs. 8-11 food groups, and OR 1.98, 95% CI 1.16-3.37 for 6-7 vs. 8-11 food groups) and food allergy (OR 2.10, 95% CI 1.29-3.42 for 1-5 vs. 8-11 food groups) were observed. Children with higher food diversity in both periods had the lowest risk of allergic diseases during the second year of life.

CONCLUSIONS

A more diverse diet within the first year of life was associated with reduced risk of allergic diseases at 1-2 years of age. Introducing higher diversity of foods from 6 to 12 months of age might be an effective strategy to improve the allergy outcomes of infants in later life.

Influence of Maternal Fish Oil Supplementation on the Risk of Asthma or Wheeze in Children: A Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Previous studies evaluating the influences of maternal fish oil supplementation on the risk of asthma or wheeze in children showed inconsistent results. We performed a meta-analysis or randomized controlled trials (RCTs) to systematically evaluate the efficacy of maternal fish oil supplementation for asthma or wheeze.

METHODS

Relevant RCTs were obtained by search of PubMed, Embase, and Cochrane's Library databases. A random-effects model incorporating the potential publication bias was used to pool the results.

RESULTS

Ten RCTs with 3,676 infants were included. Compared to control, maternal supplementation with fish oil was not associated with a reduced risk of asthma or wheeze [odds ratio (OR): 0.91, 95% confidence interval (CI): 0.72-1.14, P = 0.40] with mild heterogeneity (I ² = 28%). Subgroup analyses showed that maternal fish oil supplementation significantly reduced the risk of asthma (OR: 0.56, 95% CI: 0.35-0.91, P = 0.02; I ² = 0%), but not the risk of wheeze (OR: 1.12, 95% CI: 0.90-1.41, P = 0.32; I ² = 0%). In addition, maternal fish oil supplementation was associated with reduced risk of asthma or wheeze in high-dose studies (≥1,200 mg/d, OR: 0.65, 95% CI: 0.48-0.87, P = 0.003; I ² = 0%), but not in low-dose studies (<1,200 mg/d, OR: 1.10, 95% CI: 0.88-1.38, P = 0.39; I ² = 0%, P for subgroup difference = 0.005). Study characteristics such as the risk of the infants, timing of supplementation, and follow-up duration did not significantly affect the results.

CONCLUSIONS

Maternal fish oil supplementation may reduce the risk of clinically diagnosed asthma in children, particularly with high-dose fish oil.

Pediatric Obesity-Related Asthma: The Role of Nutrition and Nutrients in Prevention and Treatment

Childhood obesity rates have dramatically risen in numerous countries worldwide. Obesity is likely a factor in increased asthma risk, which is already one of the most widespread chronic respiratory pathologies. The pathogenic mechanism of asthma risk has still not yet been fully elucidated. Moreover, the role of obesity-related inflammation and pulmonary overreaction to environmental triggers, which ultimately result in asthma-like symptoms, and the importance of dietary characteristics is well recognized. Diet is an important adjustable element in the asthma development. Food-specific composition of the diet, in particular fat, sugar, and low-quality nutrients, is likely to promote the chronic inflammatory state seen in asthmatic patients with obesity. An unbalanced diet or supplementation as a way to control asthma more efficiently has been described. A personalized dietary intervention may improve respiratory symptoms and signs and therapeutic response. In this narrative review, we presented and discussed more recent literature on asthma associated with obesity among children, focusing on the risk of asthma among children with obesity, asthma as a result of obesity focusing on the role of adipose tissue as a mediator of systemic and local airway inflammation implicated in asthma regulation, and the impact of nutrition and nutrients in the development and treatment of asthma. Appropriate early nutritional intervention could possibly be critical in preventing and managing asthma associated with obesity among children.

Breastfeeding and Allergic Diseases: What's New?

Asthma and other allergic disorders, such as atopic dermatitis and food allergies, are common chronic health problems in childhood. The rapid rise in the prevalence of these conditions registered over the last few decades has stressed the need to identify the modifiable risk factors associated with the development of these diseases. Breast milk, recognized as the gold standard for healthy growth and development of the newborn, is one of the major factors associated with a lower incidence of allergic and infectious diseases in childhood and young adulthood. Although the underlying mechanisms for these effects are not well understood, breastfeeding leads to immune system maturation. In this narrative review, we summarize existing evidence on breastfeeding and human milk composition in relation to allergic disease prevention or development.

Perinatal and Early-Life Nutrition, Epigenetics, and Allergy

Epidemiological studies have shown a dramatic increase in the incidence and the prevalence of allergic diseases over the last several decades. Environmental triggers including risk factors (e.g., pollution), the loss of rural living conditions (e.g., farming conditions), and nutritional status (e.g., maternal, breastfeeding) are considered major contributors to this increase. The influences of these environmental factors are thought to be mediated by epigenetic mechanisms which are heritable, reversible, and biologically relevant biochemical modifications of the chromatin carrying the genetic information without changing the nucleotide sequence of the genome. An important feature characterizing epigenetically-mediated processes is the existence of a time frame where the induced effects are the strongest and therefore most crucial. This period between conception, pregnancy, and the first years of life (e.g., first 1000 days) is considered the optimal time for environmental factors, such as nutrition, to exert their beneficial epigenetic effects. In the current review, we discussed the impact of the exposure to bacteria, viruses, parasites, fungal components, microbiome metabolites, and specific nutritional components (e.g., polyunsaturated fatty acids (PUFA), vitamins, plant- and animal-derived microRNAs, breast milk) on the epigenetic patterns related to allergic manifestations. We gave insight into the epigenetic signature of bioactive milk components and the effects of specific nutrition on neonatal T cell development. Several lines of evidence suggest that atypical metabolic reprogramming induced by extrinsic factors such as allergens, viruses, pollutants, diet, or microbiome might drive cellular metabolic dysfunctions and defective immune responses in allergic disease. Therefore, we described the current knowledge on the relationship between immunometabolism and allergy mediated by epigenetic mechanisms. The knowledge as presented will give insight into epigenetic changes and the potential of maternal and post-natal nutrition on the development of allergic disease.