Early life exposure to antibiotics and the risk of childhood allergic diseases: an update from the perspective of the hygiene hypothesis

Microwave Synthesis of Fluorescent Carbon Quantum dots from Araucaria Heterophylla Gum: Application in Drug Detection

This study employed a green microwave synthesis technique to produce carbon quantum dots (CQDs) from araucaria heterophylla gum extract. The produced CQDs emit a distinct blue fluorescent light, contributing a remarkable quantum yield of 14.69%. Their average particle size measures at 1.62 ± 0.39 nm. Furthermore, these CQDs demonstrate excellent water solubility and maintain high fluorescence stability despite ionic strength, pH and time variations. Moreover, we present here for the first time that the synthesized CQDs demonstrate a rapid, exceptionally sensitive, and discerning fluorescence quenching phenomenon (IFE) concerning Cefprozil (CPR). The fluorescent probe was sensitive and specific with good linear relationships for CPR in the 0-18 µM range. The limit of detection for relationships for CPR was 2.51 µM. This study provides novel opportunities for producing high-quality luminescent CQDs that meet the requirements for various biological and environmental applications.

Antibiotic exposure during pregnancy increases risk for childhood atopic diseases: a nationwide cohort study

PURPOSE

The prevalence of atopic diseases has increased in recent decades. A possible link between antibiotic use during pregnancy and childhood atopic disease has been proposed. The aim of this study is to explore the association of antibiotic exposure during pregnancy with childhood atopic diseases from a nationwide, population-based perspective.

METHODS

This was a nationwide population-based cohort study. Taiwan's National Health Insurance Research Database was the main source of data. The pairing of mothers and children was achieved by linking the NHIRD with the Taiwan Maternal and Child Health Database. This study enrolled the first-time pregnancies from 2004 to 2010. Infants of multiple delivery, preterm delivery, and death before 5 years old were excluded. All participants were followed up at least for 5 years. Antenatal antibiotics prescribed to mothers during the pregnancy period were reviewed. Children with more than two outpatient visits, or one admission, with a main diagnosis of asthma, allergic rhinitis, or atopic dermatitis were regarded as having an atopic disease.

RESULTS

A total of 900,584 children were enrolled in this study. The adjusted hazard ratios of antibiotic exposure during pregnancy to childhood atopic diseases were 1.12 for atopic dermatitis, 1.06 for asthma, and 1.08 for allergic rhinitis, all of which reached statistical significance. The trimester effect was not significant. There was a trend showing the higher the number of times a child was prenatally exposed to antibiotics, the higher the hazard ratio was for childhood atopic diseases.

CONCLUSIONS

Prenatal antibiotic exposure might increase the risk of childhood atopic diseases in a dose-dependent manner.

Assessing Pediatric Cephalosporin Allergic Reactions Through Direct Graded Oral Challenges

BACKGROUND

Cephalosporins, β-lactam antibiotics, commonly cause allergic reactions.

OBJECTIVE

To assess the clinical characteristics and management of pediatric patients with suspected cephalosporin allergy using direct graded oral challenges (GOCs).

METHODS

Children referred for suspected cephalosporin allergy at 4 Canadian clinics were recruited over 10 years. Data on demographics, clinical reaction characteristics, and management were collected through a questionnaire. Patients underwent a direct GOC (initially 10% of the treatment dose, then 90% after 20 min), and reactions were monitored 1 week postchallenge. Families were contacted annually for up to 5 years to detect subsequent antibiotic reactions. Logistic regression analysis identified factors associated with positive GOC reactions.

RESULTS

Among the 136 patients reporting cephalosporin allergy, 75 (55.1%) were males with a median age of 3.9 years (interquartile range 2.3-8.7). Cefprozil represented the most common cephalosporin linked to the index reaction (67.6% of cases). Of the 136 direct GOCs, 5.1% had an immediate and 4.4% a nonimmediate reaction, respectively. Positive GOCs conducted in children with a history of skin-limited nonsevere rashes were classified as mild, benign skin rashes. Positive GOCs were more likely in children with food allergies (adjusted odds ratio 1.14; 95% confidence interval [95% CI] 1.00-1.29).

CONCLUSIONS

Direct GOCs are safe and effective for diagnosing pediatric cases that report nonvesicular skin-limited symptoms while being treated with cephalosporins.

Association Between Adult Antibiotic Use, Microbial Dysbiosis and Atopic Conditions - A Systematic Review

Background

Strong associations between early antibiotic exposure and increased risk of childhood allergies have been established. Antibiotics have the potential to induce microbial dysbiosis that may be linked to allergic conditions. This review examines the limited available evidence on the associations between adult antibiotic use, microbial dysbiosis and atopic conditions.

Methods

A systematic literature search was conducted using PubMed and Embase for relevant studies, published between 01-01-2000 and 08-17-2022. We searched for associations between antibiotic use, microbial dysbiosis, and allergic conditions in adults, defined as over 13 years of age for the purposes of this review.

Results

Twenty-one studies were analyzed, with the inclusion of four narrative reviews as scarce relevant literature was found when stricter selection criteria were employed. Relevant studies predominantly focused on asthma. Significant microbial differences were observed in most measures between healthy subjects and subjects with allergic conditions. However, no system-wise and strain-wise associations were evident. Notably, at the phyla level, the Bacillota and Pseudomonadota phyla were associated with asthmatics, while the Actinobacteria phylum was linked to healthy controls. Asthmatics tends to reflect upregulation in the Bacillota and Pseudomonadota phyla in both airway and gut microbiomes.

Conclusion

No compelling evidence could be found between adult antibiotic exposure, consequent microbial dysbiosis, and allergic conditions in adults. Our review is limited by scarce literature and therefore remains inconclusive. However, potential implications of antibiotic use impacting on allergic conditions justify additional research and heightened pharmacovigilance in this area.

Maternal constipation is associated with allergic rhinitis in the offspring: A nationwide retrospective cohort study

Allergic rhinitis (AR) is a common atopic disease worldwide, and it was found that babies with constipation in their early life might have an increased risk of atopic diseases, including AR. Furthermore, recent studies also indicate that the maternal gut microbiota may influence babies. Thus, we extended the definition of early life in utero and evaluated the association between maternal constipation and the risk of AR in their babies. Using the Longitudinal Health Insurance Database, a subset of Taiwan's National Health Insurance Research Database, we identified 102,820 constipated mothers and 102,820 matched controls between 2005 and 2015. Propensity score analysis was used to match birth year, child sex, birth weight, gestational age, mode of delivery, maternal comorbidities, and children antibiotics taken. Multiple Cox regression and subgroup analyzes were conducted to estimate the adjusted hazard ratio of childhood AR. The incidence of childhood AR was 83.47 per 1,000 person-years in constipated mothers. Adjusting children's sex, birth weight, gestational age, mode of delivery, maternal comorbidities, and children antibiotic use, the results showed that the children whose mothers had constipation had a 1.20-fold risk of AR compared to children of mothers without constipation. Maternal constipation was associated with an increased risk of AR. Therefore, it is important to pay close attention to pregnant mothers with constipation.

Asthma occurrence in children and early life systemic antibiotic use: an incidence density study

BACKGROUND

Results of studies evaluating the relationship between asthma occurrence and early life antibiotic use have been conflicting. The aim of this study was to investigate the relationship between occurrence of asthma in children and systemic antibiotic use in the first year of life based on an incidence density study with careful consideration of the temporal aspects of the determinant-outcome relationship.

METHODS

We conducted an incidence density study nested in a data collection project with information on 1128 mother-child pairs. Systemic antibiotic use in the first year of life was defined as excessive (≥ 4 courses) vs. non-excessive (< 4 courses) use based on information from weekly diaries. Events (cases) were defined as the first parent-reported occurrence of asthma in a child between 1 and 10 years of age. Population time 'at risk' was probed by sampling population moments (controls). Missing data were imputed. Multiple logistic regression was used to assess the association between current first asthma occurrence (incidence density) and systemic antibiotic use in the first year of life, to evaluate effect modification and adjust for confounding.

RESULTS

Forty-seven first asthma events and 147 population moments were included. Excessive systemic antibiotic use in the first year of life showed more than twice the incidence density of asthma compared to non-excessive use (adjusted IDR [95% CI]: 2.18 [0.98, 4.87], p = 0.06). The association was more pronounced in children who have had lower respiratory tract infections (LRTIs) in the first year of life compared to children who had no LRTIs in the first year of life (adjusted IDR [95% CI]: 5.17 [1.19, 22.52] versus 1.49 [0.54, 4.14]).

CONCLUSIONS

Excessive use of systemic antibiotics in the first year of life may play a role in the genesis of asthma in children. This effect is modified by the occurrence of LRTIs in the first year of life, with a stronger association observed in children experiencing LRTIs in the first year of life.

Increased antibiotic exposure in early life is associated with adverse outcomes in very low birth weight infants

BACKGROUND

The use of antibiotics in the early lives of premature infants may alter the microbiota and influence their clinical outcomes. However, whether the administration of probiotics can influence these outcomes remains unknown. In our study, probiotics were routinely administered unless contraindicated. We explored whether increased antibiotic exposure with the routine use of probiotics was associated with necrotizing enterocolitis (NEC) or bronchopulmonary dysplasia (BPD).

METHODS

A retrospective cohort study was conducted, enrolling very low birth weight (VLBW) infants admitted between January 1, 2016, and March 31, 2020, to a medical center. Days of antibiotic exposure in the first 14 days of life were recorded. The primary outcomes were NEC and BPD. Adjusted odds ratios (aORs) and 95% confidence intervals (CIs) were calculated using multivariable regression analyses to assess risk factors.

RESULTS

Of 185 VLBW infants admitted to the medical center, 132 met the inclusion criteria. Each additional day of antibiotic treatment was associated with increased odds of NEC (aOR, 1.278; 95% CI, 1.025-1.593) and BPD (aOR, 1.630; 95% CI, 1.233-2.156). The association remained in the NEC analysis after adjustment for probiotic use.

CONCLUSION

Increased antibiotic exposure in the early lives of VLBW infants was associated with increased risks of NEC and BPD. The probiotics did not influence the outcomes. Our findings suggest that clinicians should be alerted to the adverse outcomes of antibiotic use in infants with VLBWs.

Impact of a phage cocktail targeting Escherichia coli and Enterococcus faecalis as members of a gut bacterial consortium in vitro and in vivo

Escherichia coli and Enterococcus faecalis have been implicated as important players in human gut health that have been associated with the onset of inflammatory bowel disease (IBD). Bacteriophage (phage) therapy has been used for decades to target pathogens as an alternative to antibiotics, but the ability of phage to shape complex bacterial consortia in the lower gastrointestinal tract is not clearly understood. We administered a cocktail of six phages (either viable or heat-inactivated) targeting pro-inflammatory Escherichia coli LF82 and Enterococcus faecalis OG1RF as members of a defined community in both a continuous fermenter and a murine colitis model. The two target strains were members of a six species simplified human microbiome consortium (SIHUMI-6). In a 72-h continuous fermentation, the phage cocktail caused a 1.1 and 1.5 log (log10 genome copies/mL) reduction in E. faecalis and E. coli numbers, respectively. This interaction was accompanied by changes in the numbers of other SIHUMI-6 members, with an increase of Lactiplantibacillus plantarum (1.7 log) and Faecalibacterium prausnitzii (1.8 log). However, in germ-free mice colonized by the same bacterial consortium, the same phage cocktail administered twice a week over nine weeks did not cause a significant reduction of the target strains. Mice treated with active or inactive phage had similar levels of pro-inflammatory cytokines (IFN-y/IL12p40) in unstimulated colorectal colonic strip cultures. However, histology scores of the murine lower GIT (cecum and distal colon) were lower in the viable phage-treated mice, suggesting that the phage cocktail did influence the functionality of the SIHUMI-6 consortium. For this study, we conclude that the observed potential of phages to reduce host populations in in vitro models did not translate to a similar outcome in an in vivo setting, with this effect likely brought about by the reduction of phage numbers during transit of the mouse GIT.

A short review of human exposure to antibiotics based on urinary biomonitoring

Antibiotics play a role in preventing and treating infectious diseases and also contribute to other health risks for humans. With the overuse of antibiotics, they are widely distributed in the environment. Long-term exposure to multiple antibiotics may occur in humans through medication and dietary intake. Therefore, it is critical to estimate daily intake and health risk of antibiotics based on urinary biomonitoring. This review compares the strengths and weaknesses of current analytical methods to determine antibiotics in urine samples, discusses the urinary concentration profiles and hazard quotients of individual antibiotics, and overviews correlations of antibiotic exposure with the risk of diseases. Liquid chromatography-tandem mass spectrometry is most applied to simultaneously determine multiple types of antibiotics at trace levels. Solid-phase extraction with a hydrophilic-lipophilic balance adsorbent is commonly used to extract antibiotics in urine samples. Fifteen major antibiotics with relatively higher detection frequencies and concentrations include sulfaclozine, trimethoprim, erythromycin, azithromycin, penicillin V, amoxicillin, oxytetracycline, chlortetracycline, tetracycline, doxycycline, ofloxacin, enrofloxacin, ciprofloxacin, norfloxacin, and florfenicol. Humans can be easily at microbiological effect-based risk induced by florfenicol, ciprofloxacin, azithromycin, and amoxicillin. Positive associations were observed between specific antibiotic exposure and obesity, allergic diseases, and mental disorders. Overall, the accessible, automated, and environmentally friendly methods are prospected for simultaneous determinations of antibiotics at trace level in urine. To estimate human exposure to antibiotics more accurately, knowledge gaps need to be filled up, including the transformation between parent and metabolic antibiotics, urinary excretion proportions of antibiotics at low-dose exposure and pharmacokinetic data of antibiotics in humans, and the repeated sampling over a long period in future research is needed. Longitudinal studies about antibiotic exposure and the risk of diseases in different developmental windows as well as in-depth research on the pathogenic mechanism of long-term, low-dose, and joint antibiotic exposure are warranted.

Treatment with Distinct Antibiotic Classes Causes Different Pulmonary Outcomes on Allergic Airway Inflammation Associated with Modulation of Symbiotic Microbiota

Background

Asthma is a chronic pulmonary disease that affects about 300 million people worldwide. Previous studies have associated antimicrobial use with allergies, but the real impact of antibiotics on asthma is still elusive. We investigated the potential impact of amoxicillin (Amox), trimethoprim/sulfamethoxazole (TMP/SMX), and metronidazole (Metro) in a murine model of OVA-induced allergic airway inflammation.

Methods

BALB/c mice received three cycles of 7 days of antibiotics in drinking water followed by 7 days washout and were sensitized i.p. with OVA/Alum at days 0 and 14. After the end of the last antibiotic washout, the mice were challenged with aerosolized OVA. Pulmonary parameters were evaluated, and serum, BAL, and feces were collected for analysis.

Results

Amox- and TMP/SMX-treated animals displayed more severe allergic airway inflammation parameters with increased airway hyperresponsiveness, reduced lung alveolar volume, and increased levels in BAL of IL-4 and IL-6. In contrast, Metro-treated mice showed preserved FEV-50, decreased lung inflammation, and higher levels of butyrate and propionate in their feces. Metro treatment was associated with increased OVA-specific IgA in serum. BAL microbiota was abundant in allergic groups but not in nonallergic controls with the Amox-treated group displaying the increased frequency of Proteobacteria, while Metro and TMP/SMX showed increased levels of Firmicutes. In the gut, we observed the enrichment of Akkermansia muciniphila associated with reduced airway inflammation phenotype in the Metro group, even after the recovery period.

Conclusion

Our data suggest that different antibiotic treatments may impact the course of experimental allergic airway inflammation in diverse ways by several mechanisms, including modulation of short-chain fat acids production by intestinal microbiota.

Early-life exposure to antibiotics and subsequent development of atopic dermatitis

BACKGROUND

Antibiotic exposure may be associated with atopic dermatitis (AD). The objective of the study is to examine the risk of developing AD among children exposed early to antibiotics.

RESEARCH DESIGN AND METHODS

From the Italian Pedianet database, children aged 0-14 years between 2004-2017 were enrolled from birth up to at least one year. Cox proportional-hazards models were fitted to estimate Hazard Ratios (HR) and 95% Confidence Intervals (CI) for the association between antibiotic exposure during the first year of life with incident AD. Exposure was also considered as a time-varying variable.

RESULTS

73,816 children were included in the final cohort, of which 34,202 had at least one antibiotic prescription. Incident AD was present in 8% of unexposed and exposed children. Early antibiotic exposure was not associated with any excess risk of AD compared to unexposed children (HR: 1.02, 95% CI: 0.97-1.07), and no dose-response effect was observed. In the time-varying analysis, antibiotic exposure was significantly associated with AD onset (1.12, 1.07-1.17). However, when taking into account the time-lag between exposure and outcome, risks progressively decreased, suggesting possible protopathic bias.

CONCLUSION

These results are not suggestive of any significant association between exposure to antibiotics and subsequent AD onset and support the possible presence of protopathic bias.

Epigenetic regulation of pediatric and neonatal immune responses

Epigenetic regulation of transcription is a collective term that refers to mechanisms known to regulate gene transcription without changing the underlying DNA sequence. These mechanisms include DNA methylation and histone tail modifications which influence chromatin accessibility, and microRNAs that act through post-transcriptional gene silencing. Epigenetics is known to regulate a variety of biological processes, and the role of epigtenetics in immunity and immune-mediated diseases is becoming increasingly recognized. While DNA methylation is the most widely studied, each of these systems play an important role in the development and maintenance of appropriate immune responses. There is clear evidence that epigenetic mechanisms contribute to developmental stage-specific immune responses in a cell-specific manner. There is also mounting evidence that prenatal exposures alter epigenetic profiles and subsequent immune function in exposed offspring. Early life exposures that are associated with poor long-term health outcomes also appear to impact immune specific epigenetic patterning. Finally, each of these epigenetic mechanisms contribute to the pathogenesis of a wide variety of diseases that manifest during childhood. This review will discuss each of these areas in detail. IMPACT: Epigenetics, including DNA methylation, histone tail modifications, and microRNA expression, dictate immune cell phenotypes. Epigenetics influence immune development and subsequent immune health. Prenatal, perinatal, and postnatal exposures alter immune cell epigenetic profiles and subsequent immune function. Numerous pediatric-onset diseases have an epigenetic component. Several successful strategies for childhood diseases target epigenetic mechanisms.

The influence of early-life microbial exposures on long-term respiratory health

Host-microbiome interactions exert a profound influence on human physiology and health outcomes. In particular, certain characteristics of commensal microbiota during a critical period in early life are essential for the establishment of immune tone and metabolic control. An increasing body of evidence suggests that early life exposures that disrupt these interactions can substantially influence life-long risks for respiratory disease. Here, we explore how such early life exposures, including antibiotic exposure, maternal diet, preterm birth, mode of delivery, breastfeeding, and environmental variables shape the infant microbiome, and the mechanisms by such changes can in turn impact respiratory health.

Development of a conceptual model of childhood asthma to inform asthma prevention policies

Background

There is no definitive cure for asthma, as prevention remains a major goal. Decision analytic models are routinely used to evaluate the value-for-money proposition of interventions. Following best practice standards in decision-analytic modelling, the objective of this study was to solicit expert opinion to develop a concept map for a policy model for primary prevention of asthma.

Methods

We reviewed currently available decision analytic models for asthma prevention. A steering committee of economic modellers, allergists and respirologists was then convened to draft a conceptual model of paediatric asthma. A modified Delphi method was followed to define the context of the problem at hand (evaluation of asthma prevention strategies) and develop the concept map of the model.

Results

Consensus was achieved after three rounds of discussions, followed by concealed voting. In the final conceptual model, asthma diagnosis was based on three domains of lung function, atopy and their symptoms. The panel recommended several markers for each domain. These domains were in turn affected by several risk factors. The panel clustered all risk factors under three groups of ‘patient characteristic’, ‘family history’ and ‘environmental factors’. To be capable of modelling the interplay among risk factors, the panel recommended the use of microsimulation, with an open-population approach that would enable modelling phased implementation and gradual and incomplete uptake of the intervention.

Conclusions

Economic evaluation of childhood interventions for preventing asthma will require modelling of several codependent risk factors and multiple domains that affect the diagnosis. The conceptual model can inform the development and validation of a policy model for childhood asthma prevention.

Increased Prevalence of Atopic Dermatitis in Children Aged 0-3 Years Highly Exposed to Parabens

The prevalence of allergic diseases, such as bronchial asthma, atopic dermatitis, nasal allergies (pollinosis), and food allergies, has been increasing in many countries. The hygiene hypothesis was recently considered from the perspective of exposure to antimicrobial agents and preservatives, such as parabens (CAS number, 94-13-3). It currently remains unclear whether parabens, which are included in many daily consumer products such as cosmetics, shampoos, and personal care products as preservative antimicrobial agents, induce or aggravate allergies. Therefore, the aim of the present study was to examine the relationship between exposure to parabens and the prevalence of allergic diseases in Japanese children. The cross-sectional epidemiology of 236 children aged 0-3 years who underwent health examinations in Shika town in Japan assessed individual exposure to parabens using urinary concentrations of parabens. The results obtained showed that the prevalence of atopic dermatitis was significantly higher in children with high urinary concentrations of parabens than in those with low concentrations (p < 0.001). This relationship remained significant after adjustments for confounding factors, such as age, sex, Kaup's index, and passive smoking (p < 0.001). In conclusion, the present results from a population study suggested a relationship between atopic dermatitis and exposure to parabens. A longitudinal study using a larger sample number and a detailed examination of atopic dermatitis, including EASI scores and exposure to parabens, will be necessary.

Dangerous liaisons: Bacteria, antimicrobial therapies, and allergic diseases

Microbiota composition and associated metabolic activities are essential for the education and development of a healthy immune system. Microbial dysbiosis, caused by risk factors such as diet, birth mode, or early infant antimicrobial therapy, is associated with the inception of allergic diseases. In turn, allergic diseases increase the risk for irrational use of antimicrobial therapy. Microbial therapies, such as probiotics, have been studied in the prevention and treatment of allergic diseases, but evidence remains limited due to studies with high heterogeneity, strain-dependent effectiveness, and variable outcome measures. In this review, we sketch the relation of microbiota with allergic diseases, the overuse and rationale for the use of antimicrobial agents in allergic diseases, and current knowledge concerning the use of bacterial products in allergic diseases. We urgently recommend 1) limiting antibiotic therapy in pregnancy and early childhood as a method contributing to the reduction of the allergy epidemic in children and 2) restricting antibiotic therapy in exacerbations and chronic treatment of allergic diseases, mainly concerning asthma and atopic dermatitis. Future research should be aimed at antibiotic stewardship implementation strategies and biomarker-guided therapy, discerning those patients that might benefit from antibiotic therapy.

Machine Learning for Predicting the Risk for Childhood Asthma Using Prenatal, Perinatal, Postnatal and Environmental Factors

The prevalence rate for childhood asthma and its associated risk factors vary significantly across countries and regions. In the case of Morocco, the scarcity of available medical data makes scientific research on diseases such as asthma very challenging. In this paper, we build machine learning models to predict the occurrence of childhood asthma using data from a prospective study of 202 children with and without asthma. The association between different factors and asthma diagnosis is first assessed using a Chi-squared test. Then, predictive models such as logistic regression analysis, decision trees, random forest and support vector machine are used to explore the relationship between childhood asthma and the various risk factors. First, data were pre-processed using a Chi-squared feature selection, 19 out of the 36 factors were found to be significantly associated (p-value < 0.05) with childhood asthma; these include: history of atopic diseases in the family, presence of mites, cold air, strong odors and mold in the child's environment, mode of birth, breastfeeding and early life habits and exposures. For asthma prediction, random forest yielded the best predictive performance (accuracy = 84.9%), followed by logistic regression (accuracy = 82.57%), support vector machine (accuracy = 82.5%) and decision trees (accuracy = 75.19%). The decision tree model has the advantage of being easily interpreted. This study identified important maternal and prenatal risk factors for childhood asthma, the majority of which are avoidable. Appropriate steps are needed to raise awareness about the prenatal risk factors.

Atopic Manifestations in Children Born Preterm: A Long-Term Observational Study

(1) Background: Preterm birth exposes the infant to the known risk factors for atopic diseases. We aimed to study the neonatal risk factors and to describe the clinical manifestations of atopy, including the march of symptoms, in a cohort of preschool children born preterm. (2) Methods: We enrolled neonates with gestational age < 32 weeks or birth weight < 1500 g. We classified patients in cases and controls according to the presence of at least one atopic manifestation. (3) Results: We observed 72 cases and 93 controls. Multivariate models showed that the administration of more than one cycle of antibiotics (B 0.902, p = 0.026) and gestational diabetes (B 1.207, p = 0.035) influence the risk of atopy in babies born preterm. In addition, risk of atopic dermatitis was influenced by gestational age < 29 weeks (B -1.710, p = 0.025) and gestational diabetes (B 1.275, p = 0.027). The risk of wheeze was associated with familiarity for asthma (B 1.392, p = 0.022) and the administration of more than one cycle of antibiotics (B 0.969, p = 0.025). We observed a significant reduction in the rate of atopic manifestation after 2 years of life (33.9% vs. 23.8%, p < 0.05). (4) Conclusions: Modifiable (gestational diabetes, antibiotics use) and unmodifiable (familiarity for asthma) conditions influence the risk of atopy in babies born preterm. Extreme prematurity reduces the risk of atopic dermatitis. Preterm babies showed a peculiar atopic march.

Association of early-life gut microbiome and lifestyle factors in the development of eczema in Hong Kong infants

Childhood eczema is common but its prevalence is variable in different regions of the world. In this study, we explore the associations of various risk factors such as the microbiome, environment, lifestyle, diet and maternal stress with the development of eczema among infants in Hong Kong. Upon enrolment in the study, the infants' parents provided demographic data by self-reporting. At enrolment and 1 year after birth, the infants' allergic conditions, lifestyles and dietary factors and the degree of maternal stress were assessed using various questionnaires. The infants' gut microbiomes were analysed by 16S RNA sequencing, and the longitudinal changes in various bacterial strains were compared between control and eczema-affected groups. Multivariate analyses (after adjustment for other significant factors) revealed that the changes in the abundance of Hungatella hathewayi in the gut were significantly associated with the development of eczema (p = 0.005). In conclusion, the increased abundance of Hungatella hathewayi was associated with an increased risk of developing eczema by 1 year of age. This study thus explored the potential risk factors for the development of eczema in Hong Kong infants, and sheds light on the possible association between early-life gut microbiome and other environmental factors.

Broad-Spectrum Antibiotics and Risk of Graft-versus-Host Disease in Pediatric Patients Undergoing Transplantation for Acute Leukemia: Association of Carbapenem Use with the Risk of Acute Graft-versus-Host Disease

Variation in the gastrointestinal (GI) microbiota after hematopoietic cell transplantation (HCT) has been associated with acute graft-versus-host disease (aGVHD). Because antibiotics induce dysbiosis, we examined the association of broad-spectrum antibiotics with subsequent aGVHD risk in pediatric patients undergoing HCT for acute leukemia. We performed a retrospective analysis in a dataset merged from 2 sources: (1) the Center for International Blood and Marrow Transplant Research, an observational transplantation registry, and (2) the Pediatric Health Information Services, an administrative database from freestanding children's hospitals. We captured exposure to 3 classes of antibiotics used for empiric treatment of febrile neutropenia: (1) broad-spectrum cephalosporins, (2) antipseudomonal penicillins, and (3) carbapenems. The primary outcome was grade II-IV aGVHD; secondary outcomes were grade III-IV aGVHD and lower GI GVHD. The adjusted logistic regression model (full cohort) and time-to-event analysis (subcohort) included transplantation characteristics, GVHD risk factors, and adjunctive antibiotic exposures as covariates. The full cohort included 2550 patients at 36 centers; the subcohort included 1174 patients. In adjusted models, carbapenems were associated with an increased risk of grade II-IV aGVHD in the full cohort (adjusted odds ratio [aOR], 1.24; 95% confidence interval [CI], 1.02 to 1.51) and subcohort (sub hazard ratio [HR], 1.31; 95% CI, 0.99 to 1.72), as well as with an increased risk of grade III-IV aGVHD (subHR, 1.77; 95% CI, 1.25 to 2.52). Early carbapenem exposure (before day 0) especially impacted aGVHD risk. For antipseudomonal penicillins, the associations with aGVHD were in the direction of increased risk but were not statistically significant. There was no identified association between broad-spectrum cephalosporins and aGVHD. Carbapenems, more than other broad-spectrum antibiotics, should be used judiciously in pediatric HCT recipients to minimize aGVHD risk. Further research is needed to clarify the mechanism underlying this association.

Low-Dose LPS Induces Tolerogenic Treg Skewing in Asthma

The mechanism(s) underlying endotoxin tolerance in asthma remain elusive. As the endotoxin lipopolysaccharide (LPS) affects the expression of the regulatory T-cell (Treg)-suppressive glucocorticoid-induced tumor necrosis factor receptor ligand (GITRL) on antigen-presenting dendritic cells (DCs), we hypothesized that LPS-induced changes in DC GITRL expression may impact Treg-mediated T-helper (Th) cell suppression and the induction of endotoxin tolerance. Here, we propose a novel mechanism by which low-dose LPS inhalation in neonatal mice induces endotoxin tolerance, thereby offering protection from later asthma development. Three-day old wild-type and Toll-like receptor 4 (TLR4)-deficient neonatal mice were exposed to low-dose LPS (1 μg) intranasally for 10 consecutive days prior to ovalbumin (OVA)-induced asthma to better understand the tolerogenic mechanism(s) of low-dose LPS pre-exposure. In vivo findings were validated using in vitro co-culturing studies of primary CD11c⁺ DCs and CD4⁺ T-cells with or without low-dose LPS pre-exposure before OVA stimulation. Low-dose LPS pre-exposure upregulated the Treg response and downregulated pathogenic Th2 and Th17 responses through promoting apoptosis of Th2 and Th17 cells. Low-dose LPS pre-exposure downregulated DC GITRL expression and T-cell GITR expression. Artificial DC GITRL expression abrogated the tolerogenic Treg-skewing effect of low-dose LPS pre-exposure. Low-dose LPS pre-exposure inhibited TRIF/IRF3/IFNβ signaling and upregulated expression of tolerogenic TRIF/IRF3/IFNβ negative regulators in a TLR4-dependent manner. This tolerogenic DC GITRL downregulation was attributable to TRIF/IRF3/IFNβ signaling inhibition. Low-dose LPS pre-exposure produces tolerogenic Treg skewing in neonatal asthmatic mice, a phenomenon attributable to TLR4-dependent TRIF/IRF3/IFNβ-mediated DC GITRL downregulation.

First-Year Antibiotics Exposure in Relation to Childhood Asthma, Allergies, and Airway Illnesses

Background: Associations of early antibiotics exposures with childhood asthma, allergies, and airway illnesses are debated. Objectives: We aimed to investigate associations of first-year antibiotics exposure with childhood asthma, allergies, and airway illnesses. Methods: A cross-sectional study was conducted among preschoolers in Shanghai, China during 2011–2012. A questionnaire regarding household environment and lifestyles and childhood health outcomes was reported by the child’s parents. Results: In total, 13,335 questionnaires (response rate: 85.3%) were analyzed and 3049 (24.1%) children had first-year antibiotics exposure. In the multivariate logistic regression analyses, first-year antibiotics exposure had significant associations with the higher odds of lifetime-ever pneumonia (adjusted OR, 95% CI: 2.15, 1.95–2.37), croup (1.46, 1.24–1.73), wheeze (1.44, 1.30–1.60), asthma (1.38, 1.19–1.61), food allergy (1.29, 1.13–1.46), and allergic rhinitis (1.23, 1.07–1.41), and as well as current (one year before the survey) common cold (≥3 times) (1.38, 1.25–1.52), dry cough (1.27, 1.13–1.42), atopic dermatitis (1.25, 1.09–1.43), wheeze (1.23, 1.10–1.38), and rhinitis symptoms (1.15, 1.04–1.26). These associations were different in children with different individual characteristics (age, sex, family history of atopy, and district) and other early exposures (breastfeeding, home decoration, pet-keeping, and environmental tobacco smoke). Conclusions: Our results indicate that first-year antibiotics exposure could be a strong risk factor for childhood pneumonia, asthma, allergies, and their related symptoms. The individual characteristics and other early exposures may modify effects of early antibiotic exposure on childhood allergies and airway illnesses.

Infection, antibiotic exposure and development of atopic dermatitis: A nationwide case-control study

Previous studies suggest an association between atopic dermatitis (AD) and exposure to microorganisms and antibiotics. However, these studies have limitations, and the sole influence on the development of AD was elusive. We performed a nationwide population-based case-control study in a Korean population to investigate the association between AD and early-life infection or antibiotic exposure. A total of 244 805 children with AD from the 2 283 601 children born between January 2010 and December 2014 and an equal number of sex- and age-matched healthy children were enrolled. A conditional logistic regression analysis showed that the episode of infection and antibiotic exposure were associated with an increased risk of AD (odds ratio [OR], 1.60; 95% confidence interval [CI], 1.58-1.63 for infection; and OR, 1.11; 95% CI, 1.09-1.13 for antibiotic exposure). A dose-dependent relationship was observed between risk for AD, the number of infection episodes and antibiotic cycles and the duration of antibiotic exposure. On further analysis using a conditional logistic model, the risk of AD was less when the antibiotics were used during the infection episode than that without the use of antibiotics, especially if the duration of the infection was short. Although our study could not consider the effect of cause or severity of infection, class of antibiotics and genetic or environmental factors of enrolled subjects, our results suggested that infection and antibiotic exposure were associated with an increased risk of AD. In addition, the results also implied that the use of antibiotics during an infection episode can decrease the risk of AD induced by the infection and that appropriate management of infections can minimize the risk of AD induced by infection or antibiotics.

Increasing allergy: are antibiotics the elephant in the room?

Antibiotics cause dramatic changes to the human microbiome. The composition of the microbiome has been associated with changes in the immune system and these changes are beginning to be linked to immune diseases. Thus, antibiotics have been implicated as a significant contributor to the continual rise of allergies and autoimmune disease in developed countries. This recognition will hopefully result in the development of post-antibiotic therapies that restore a healthy microbiome and reduce immune system disorders.

Maternal antibiotic concentrations in pregnant women in Shanghai and their determinants: A biomonitoring-based prospective study

Consumption of antibiotics is continuing to increase, with China accounting for approximately one quarter of the global intake. As a class of emerging environmental contaminants, antibiotics may pose a potential threat to human health, especially in children. However, the internal antibiotic exposure levels in pregnant women and their determinants remain unclear. Here we investigated the urinary creatinine-corrected concentration of 15 antibiotics in 762 pregnant women from the Shanghai Prenatal Cohort, by liquid chromatography-tandem mass spectrometry. Logistic regression analysis identified associations between high-antibiotic-level and maternal dietary factors. Results show that cumulatively antibiotics were detected at a frequency of 0.13 - 82.7%, with veterinary antibiotics (VAs) and preferred veterinary antibiotics (PVAs) detected in 76.9% and 98.2% of samples, respectively; PVAs were the most significant contributors to hazard index values > 1. Further, ciprofloxacin was the predominant antibiotic (median: 73.5 μg/mg creatinine), followed by norfloxacin (54.2 μg/mg creatinine); while sulfamethoxazole, enrofloxacin, and ciprofloxacin levels, used as a PVA or VA, were significantly higher in normal-weight and underweight women compared to overweight and obese women. Also, sulfamethoxazole, sulfadiazine, and ciprofloxacin were more frequently detected in mothers with a relatively low education degree. Interestingly, pregnant women with higher milk intake had a 1.96-times (95% CI: 1.10-3.49) greater risk of high-VA-exposure-level than the lower-intake group. The odds of exposure to high PVA, VA, PVA + VA, and all antibiotics levels for mothers with high egg consumption frequency were more than twice that of low-consumption individuals. Collectively, pregnant women in Shanghai are exposed to multiple environmental antibiotics, primarily as PVAs and VAs. Herein, we provide evidence for the association between dietary factors and maternal environmental antibiotic exposure in China. Special attention to antibiotic exposure and confirmation of potential determinants should be taken in the future.

Early-life antibiotic use and risk of asthma and eczema: results of a discordant twin study

RATIONALE

Early-life antibiotic use has been associated with the development of atopic diseases, but the aetiology remains unclear. To elucidate the aetiology, we used a discordant twin design to control for genetic and environmental confounding.

METHODS

We conducted a retrospective cohort study in twins aged 3-10 years from the Netherlands Twin Register (NTR, n=35 365) and a replication study in twins aged 9 years from the Childhood and Adolescent Twin Study in Sweden (CATSS, n=7916). Antibiotic use was recorded at age 0-2 years. Doctor-diagnosed asthma and eczema were reported by parents when children were aged 3-12 years in both cohorts. Individuals were included in unmatched analyses and in co-twin control analyses with disease discordant twin pairs.

RESULTS

Early-life antibiotic use was associated with increased risk of asthma (NTR OR 1.34, 95% CI 1.28-1.41; CATSS OR 1.45, 95% CI 1.34-1.56) and eczema (NTR OR 1.08, 95% CI 1.03-1.13; CATSS OR 1.07, 95% CI 1.01-1.14) in unmatched analyses. Co-twin analyses in monozygotic and dizygotic twin pairs showed similar results for asthma (NTR OR 1.54, 95% CI 1.20-1.98; CATSS OR 2.00, 95% CI 1.28-3.13), but opposing results for eczema in the NTR (OR 0.99, 95% CI 0.80-1.25) and the CATSS (OR 1.67, 95% CI 1.12-2.49). The risk of asthma increased for antibiotics prescribed for respiratory infections (CATSS OR 1.45, 95% CI 1.34-1.56), but not for antibiotics commonly used for urinary tract/skin infections (CATSS OR 1.02, 95% CI 0.88-1.17).

CONCLUSION

Children exposed to early-life antibiotic use, particularly prescribed for respiratory infections, may be at higher risk of asthma. This risk can still be observed when correcting for genetic and environmental factors. Our results could not elucidate whether the relationship between early-life antibiotic use and eczema is confounded by familial and genetic factors.

Oral and nasal probiotic administration for the prevention and alleviation of allergic diseases, asthma and chronic obstructive pulmonary disease

Interaction between a healthy microbiome and the immune system leads to body homeostasis, as dysbiosis in microbiome content and loss of diversity may result in disease development. Due to the ability of probiotics to help and modify microbiome constitution, probiotics are now widely used for the prevention and treatment of different gastrointestinal, inflammatory, and, more recently, respiratory diseases. In this regard, chronic respiratory diseases including chronic obstructive pulmonary disease (COPD), asthma and allergic rhinitis are among the most common and complicated respiratory diseases with no specific treatment until now. Accordingly, many studies have evaluated the therapeutic efficacy of probiotic administration (mostly via the oral route and much lesser nasal route) on chronic respiratory diseases. We tried to summarise and evaluate these studies to give a perspective of probiotic therapy via both the oral and nasal routes for respiratory infections (in general) and chronic respiratory diseases (specifically). We finally concluded that probiotics might be useful for allergic diseases. For asthmatic patients, probiotics can modulate serum cytokines and IgE and decrease eosinophilia, but with no significant reduction in clinical symptoms. For COPD, only limited studies were found with uncertain clinical efficacy. For intranasal administration, although some studies propose more efficiency than the oral route, more clinical evaluations are warranted.

Azithromycin suppresses Th1- and Th2-related chemokines IP-10/MDC in human monocytic cell line

BACKGROUND

Cytokines and chemokines play critical roles in the pathogenesis of asthma. Azithromycin, a macrolides, is frequently used in asthmatic children with lower respiratory tract infection and is reported having anti-inflammatory and immunomodulatory effects. However, the effects of azithromycin on the expression of TNF-α, Th1- and Th2-related chemokines, and neutrophil chemoattractant are unknown. We investigated the in vitro effects of azithromycin on the expression of TNF-α, Th1-related chemokine interferon-γ-inducible protein-10 (IP-10/CXCL10), Th2-related chemokine macrophage-derived chemokine (MDC/CCL22) and neutrophil chemoattractant growth-related oncogene-α (GRO-α/CXCL1) in THP-1 cells as a model for human monocytes.

METHODS

THP-1 cells were pretreated with various concentrations of azithromycin before Toll-like receptor 4 (TLR4) agonist lipopolysaccharide (LPS) stimulation. TNF-α, IP-10, MDC and GRO-α were measured by ELISA. Intracellular signaling was investigated by pathway inhibitors and Western blot.

RESULT

Azithromycin suppressed MDC and IP-10 expression in LPS-stimulated THP-1 cells. However, azithromycin had no effect LPS-induced TNF-α and GRO-α expression. Western blotting revealed that azithromycin suppressed LPS-induced phosphorylation of mitogen-activated protein kinase (MAPK)-JNK and ERK expression, and also suppressed LPS-induced phosphorylation of nuclear factor (NF) κB-p65 expression.

CONCLUSION

Azithromycin suppressed LPS-induced MDC expression via the MAPK-JNK and the NFκB-p65 pathway. Azithromycin also suppressed LPS-induced IP-10 via the MAPK-JNK/ERK and the NFκB-p65 pathway. Azithromycin may benefit asthmatic patients by suppressing chemokines expression.

Thinking bigger: How early-life environmental exposures shape the gut microbiome and influence the development of asthma and allergic disease

Imbalance, or dysbiosis, of the gut microbiome of infants has been linked to an increased risk of asthma and allergic diseases. Most studies to date have provided a wealth of data showing correlations between early-life risk factors for disease and changes in the structure of the gut microbiome that disrupt normal immunoregulation. These studies have typically focused on one specific risk factor, such as mode of delivery or early-life antibiotic use. Such "micro-level" exposures have a considerable impact on affected individuals but not necessarily the whole population. In this review, we place these mechanisms under a larger lens that takes into account the influence of upstream "macro-level" environmental factors such as air pollution and the built environment. While these exposures likely have a smaller impact on the microbiome at an individual level, their ubiquitous nature confers them with a large influence at the population level. We focus on features of the indoor and outdoor human-made environment, their microbiomes and the research challenges inherent in integrating the built environment microbiomes with the early-life gut microbiome. We argue that an exposome perspective integrating internal and external microbiomes with macro-level environmental factors can provide a more comprehensive framework to define how environmental exposures can shape the gut microbiome and influence the development of allergic disease.

Microbiome and Mental Health, Specifically as It Relates to Adolescents

PURPOSE OF REVIEW

This article reviews the relationship of the microbiome, the gut-brain axis, and depression. It also will review factors which can influence this relationship, such as chronic stress, medications, and the Western diet typically consumed by adolescents.

RECENT FINDINGS

Changes in the gut microbiome increase the release of microbial lipopolysaccharides (LPS) which activate a gut inflammatory response. Gut pro-inflammatory cytokines stimulate the afferent vagal nerve which in turn impacts the hypothalamic-pituitary-adrenal (HPA) axis inducing symptoms associated with depression. Recent research suggests that gut inflammation can induce neuroinflammation which, in turn, stimulates microglia activation and the kynurenine pathway and can activate systemic inflammation-inducing depressive symptoms. Promoting a healthy diet and lifestyle changes, limiting exposure to pesticides, limiting medications that affect the microbiome and the use of such things pre/probiotics and other interventions may complement existing efforts to curb the rise in depression. Alternative and complementary therapies may serve as effective treatments in adolescents with depression.

Should fast breathing pneumonia cases be treated with antibiotics? The scientific rationale for revisiting management in Low and Middle income countries

BACKGROUND

Pneumonia is the largest single contributor to child mortality and the problem is more acute in low and middle income countries. The World Health Organization (WHO) currently recommends oral antibiotic treatment for all children with fast breathing pneumonia without danger signs. It is, however, widely acknowledged that most such infections are viral and self-limiting and that the evidence for the guidance is weak.

RATIONALE

Overuse of antibiotics exposes children to adverse events, increases cost for families, burdens already stretched health care resources and may contribute to development of antibiotic resistance.

CONCLUSION

There is equipoise regarding utility of antibiotic in case of fast breathing pneumonia and no high quality trial evidence exists. This paper provides further information behind the rationale for conducting non-inferiority trials to test the hypothesis that antibiotics may not be necessary for children with fast breathing as the sole symptomatology.

Antibiotic exposure and asthma development in children with allergic rhinitis

PURPOSE

Early-life antibiotic use may be associated with asthma, yet whether this association also exists in patients with allergic rhinitis (AR) remains unknown. We investigated the association between antibiotic exposure and asthma development in AR children.

METHODS

AR patients less than 18 year-old were enrolled from the Taiwan National Health Insurance Database, which reported information from 2005 to 2010. The case group was defined as having newly developed asthma, and the control group was defined as never having an asthma diagnosis. The age of first exposure to antibiotic prescriptions and antibiotic exposure records preceding 5 years before the first asthma diagnosis were obtained from drug prescription records. The odds ratio (OR) was examined after adjusting for age, gender, resident urbanization, underlying medical disorders and medications.

RESULTS

A total of 3236 AR patients with newly developed asthma and 9708 AR patients without asthma were included in this study. Antibiotic exposure before the age of 3 years was not associated with asthma development. Preceding 5-year antibiotic exposure increased the risk of asthma development with a dose-response relationship, even for antibiotics with low cumulative defined daily doses (adjusted OR 1.40, 95% CI 1.12-1.75). Preceding 5-year exposure to penicillin and macrolide significantly increased the risk of asthma when diagnosed before age 12 in AR patients, but this was not statistically significant when asthma diagnosed after age 12.

CONCLUSION

Preceding 5-year antibiotic exposure, particularly to penicillin group of amoxicillin and macrolides, is associated with the risk of asthma development before age 12 in AR children.

Association between antibiotic treatment during pregnancy and infancy and the development of allergic diseases

BACKGROUND

Allergies are a serious public health issue, and prevalences are rising worldwide. The role of antibiotics in the development of allergies has repeatedly been discussed, as results remain inconsistent. The aim of this study was to investigate the association between pre- and post-natal antibiotic exposure and subsequent development of allergies (atopic dermatitis, food allergy, asthma, atopic sensitization and allergic rhinitis).

METHODS

A total of 1080 children who participated in a European birth cohort study (PASTURE) were included in this analysis. Data on antibiotic exposure during pregnancy and/or first year of life and allergic diseases were collected by questionnaires from pregnancy up to 6 years of age and analysed by performing logistic regressions. To take into account reverse causation, we included models, where children with diagnosis or symptoms of the respective disease in the first year of life were excluded.

RESULTS

Antibiotic exposure in utero was significantly and positively associated with atopic dermatitis and food allergy. The strongest effect was on diseases with onset within the first year of life (for atopic dermatitis: aOR 1.66, 95% CI 1.11-2.48 and for food allergy: aOR 3.01, 95% CI 1.22-7.47). Antibiotics in the first year of life were positively associated with atopic dermatitis up to 4 years (aOR 2.73, 95% CI 1.66-4.49) and also suggested a dose-response relationship. A tendency was observed with asthma between 3 and 6 years (aOR 1.65, 95% CI 0.95-2.86).

CONCLUSIONS

Our findings show positive associations between exposure to antibiotics and allergies, mainly atopic dermatitis and food allergy within the first year of life, after prenatal exposure, and atopic dermatitis and asthma after post-natal exposure to antibiotics in children born in rural settings.

Sources of indoor particulate matter (PM) and outdoor air pollution in China in relation to asthma, wheeze, rhinitis and eczema among pre-school children: Synergistic effects between antibiotics use and PM10 and second hand smoke

We studied indoor sources of indoor particulate matter (PM), outdoor air pollution and antibiotic use in relation to asthma, rhinitis and eczema among pre-school children and investigated synergistic effects between PM and antibiotics use. Children (3-6y) from randomly selected day care centres in seven cities across China were included (n = 39,782). Data on ambient temperature and air pollution were collected from local monitoring stations. Data on indoor PM sources (ETS, burning of incense or mosquito coils and biomass for cooking), antibiotics use and health (doctor diagnosed asthma and rhinitis, lifetime eczema, current wheeze and current rhinitis) were assessed by a parental questionnaire. Associations were calculated by multilevel logistic regression. Asthma diagnosis was associated with outdoor temperature, NO₂ and burning mosquito coils. Rhinitis diagnosis was associated with NO₂, ETS, gas cooking and burning biomass for cooking. Lifetime eczema was associated with temperature, PM_10, NO₂, ETS, biomass cooking and burning mosquito coils. Burning incense was associated with current wheeze and current rhinitis. Children using antibiotics had more asthma, wheeze, rhinitis, and eczema. Excluding children with respiratory infections did not change associations with antibiotics use. Antibiotics use enhanced the effects of ETS and PM₁₀ (a synergistic effect). In conclusion, a warmer climate, outdoor NO₂ and PM_10, ETS, gas cooking and burning biomass, incense and mosquito coils can increase the risk of asthma, wheeze, rhinitis and eczema among pre-school children in China. Antibiotics use is a risk factor for childhood asthma, wheeze, rhinitis and eczema and ETS and outdoor PM₁₀ can enhance the effect.

The Exposome and Asthma

This article on exposome and asthma focuses on the interaction of patients and their environments in various parts of their growth, development, and stages of life. Indoor and outdoor environments play a role in pathogenesis via levels and duration of exposure, with genetic susceptibility as a crucial factor that alters the initiation and trajectory of common conditions such as asthma. Knowledge of environmental exposures globally and changes that are occurring is necessary to function effectively as medical professionals and health advocates.

Relationship between the Use of Parabens and Allergic Diseases in Japanese Adults—A Cross-Sectional Study

It currently remains unclear whether parabens, which are preservatives added to cosmetics, shampoos, and personal care products that exhibit biocidal activities, exert allergic effects in adults. The aim of the present study was to examine the relationship between the use of parabens and the prevalence of allergic diseases in Japanese adults. This population-based cross-sectional study comprised 2005 participants aged 40 years or older living in Shika Town in Japan who answered a self-administered questionnaire on allergic diseases and the daily use of household goods. The information obtained was then analyzed to assess the exposure to parabens (response rate: 77.9%). The prevalence of nasal allergies, atopic conjunctivitis, and total allergies was significantly higher in women who used parabens. These differences remained significant after adjustments for confounding factors including age, body mass index, smoking, alcohol, exercise, sleep, income, education, and marital status. No relationship between the prevalence of atopic dermatitis and the use of parabens was observed in men or women. However, the present results demonstrated that the prevalence of nasal allergies and atopic conjunctivitis was associated with use of parabens in women, suggesting that parabens may induce allergic responses.

Perinatal antibiotic exposure alters composition of murine gut microbiota and may influence later responses to peanut antigen

Background

Accumulating evidence suggests that the gut microbiota shapes developmental processes within the immune system. Early life antibiotic use is one factor which may contribute to immune dysfunction and the recent surge in allergies by virtue of its effects on gut microbiota.

Objective and methods

As a first step towards determining whether a relationship exists between perinatal antibiotic induced changes in the gut microbiota and the later development of a peanut allergy, we exposed newborn mice to either the broad-spectrum antibiotic vancomycin or to a vehicle for 6 weeks and then used a novel murine model of peanut allergy.

Results

Early-life treatment with vancomycin resulted in a significant shift in the gut microbiota community characterized by a reduction in the abundance of firmicutes and preponderance of inflammatory proteobacteria. Mice with an antibiotic-altered microbiota, showed a localized allergic-like response characterized by ear swelling and scratching following intra-dermal peanut antigen challenge. Likewise, circulating IgE levels were increased in antibiotic-treated mice, but no evidence of a systemic allergic or anaphylactic-like response was observed. Importantly, we utilized the naturally occurring pro-inflammatory cytokine, tumor necrosis factor-α (TNF-α), rather than the more commonly used cholera toxin, as an adjuvant together with the peanut antigen.

Conclusion

Our data suggest that early antibiotic exposure promotes a shift in the gut microbiota community that may in turn, influence how mice later respond to a TNF-α + antigen challenge. However, further studies verifying the capacity of microbiota restoration to protect against allergic responses will be needed to confirm a causal role of antibiotic-induced microbiota variations in promoting allergic disease phenotypes.

The role of environmental factors in allergy: A critical reappraisal

Allergies are usually referred to as type I hypersensitivity reactions against innocuous environmental antigens, characterized by a Th2/IgE-dominated inflammation. They can manifest themselves in various organs, such as skin, gastrointestinal and respiratory tract, and comprise diseases as diverse as allergic rhinitis and conjunctivitis, bronchial asthma, oral allergy syndrome, food allergy, urticaria and atopic eczema, but also anaphylactic shock. Within the last decades, there was a significant global increase in allergy prevalence, which has been mostly attributed to changes in environment and lifestyle. But which, among all factors discussed, are the most relevant, and what are the mechanisms by which these factors promote or prevent the development of allergic diseases? To answer this, it is necessary to go back to the two key questions that have occupied allergy researchers for the last decades: Firstly, what makes an allergen an allergen? Secondly, why are more and more individuals affected? Within the last decade, we have made considerable progress in answering these questions. This review gives an overview over scientific progress in the field, summarizes latest findings and points out future prospective and research needs.

It's not just the food you eat: Environmental factors in the development of food allergies

The dramatic rise in the prevalence of food allergy and food allergy-associated anaphylaxis in the past few decades has fueled investigative interest into understanding this puzzling trend. Here, we review the question as to whether important external environmental determinants beyond dietary habits and exposure to food allergens are involved. This review will summarize our current understanding of these environment determinants, derived from the latest experimental and epidemiological research. Specifically, we will review the role of exposures that affect skin barrier function, development of a diverse microbiome, and food processing. Additional exposures of concern are insufficient sunlight, endocrine disrupting chemicals and pesticides, and use of specific pharmaceutical agents that may drive or modify the risk for food allergy. Despite limitations in the quantity and quality of research to date, many new epidemiological associations and experimental data in support of this paradigm have emerged.

Prenatal antibiotic exposure and childhood asthma: a population-based study

Antibiotic use during infancy alters gut microbiota and immune development and is associated with an increased risk of childhood asthma. The impact of prenatal antibiotic exposure is unclear. We sought to characterise the association between prenatal antibiotic exposure and childhood asthma.We performed a population-based cohort study using prescription records, hospitalisation records and physician billing claims from 213 661 mother-child dyads born in Manitoba, Canada between 1996 and 2012. Associations were determined using Cox regression, adjusting for maternal asthma, postnatal antibiotics and other potential confounders. Sensitivity analyses evaluated maternal antibiotic use before and after pregnancy.36.8% of children were exposed prenatally to antibiotics and 10.1% developed asthma. Prenatal antibiotic exposure was associated with an increased risk of asthma (adjusted hazard ratio (aHR) 1.23, 95% CI 1.20-1.27). There was an apparent dose response (aHR 1.15, 95% CI 1.11-1.18 for one course; aHR 1.26, 95% CI 1.21-1.32 for two courses; and aHR 1.51, 95% CI 1.44-1.59 for three or more courses). Maternal antibiotic use during 9 months before pregnancy (aHR 1.27, 95% CI 1.24-1.31) and 9 months postpartum (aHR 1.32, 95% CI 1.28-1.36) were similarly associated with asthma.Prenatal antibiotic exposure was associated with a dose-dependent increase in asthma risk. However, similar associations were observed for maternal antibiotic use before and after pregnancy, suggesting the association is either not directly causal, or not specific to pregnancy.

The Effect of Hidden Female Smoking on the Association between Smoking and Asthma

BACKGROUND

The association between smoking and asthma remains controversial. In our previous study, we were not able to show an association between asthma and smoking in Korean adults. One Korean study demonstrated underreporting of smoking history by female adults. The aim of the present study was to investigate the effects of hidden female smoking on the association between asthma and smoking in Korean adults.

METHODS

Data were acquired from 23,483 men and women aged ≥19 years who participated in the Korean National Health and Nutrition Examination Surveys (KNHANES).

RESULTS

The prevalence of asthma was 1.5%, the self-reported smoking prevalence was 32.4%, and the cotinine-verified smoking prevalence was 30.3%. Of the male cotinine-verified smokers, 6.4% were self-reported nonsmokers (2.7% never smokers and 3.7% ex-smokers), whereas 48.8% of the female cotinine-verified smokers were self-reported nonsmokers (43.2% never smokers and 5.6% ex-smokers). In males, the adjusted odds ratio of the association between smoking and asthma was 0.738 (confidence interval, CI: 0.393-1.173) in self-reported and 0.767 (CI: 0.515-1.143) in cotinine-verified smoking; in females, the adjusted odds ratio was 1.945 (CI: 1.348-2.805) in self-reported and 1.531 (CI: 1.076-2.179) in cotinine-verified smoking.

CONCLUSIONS

Our study showed smoking was associated with asthma in females but not in males.

Parental-reported allergic disorders and emergency department presentations for allergy in the first five years of life; a longitudinal birth cohort

Background

To measure rates of parental-report of allergic disorders and ED presentations for allergic disorders in children, and to describe factors associated with either.

Methods

An existing cohort of 3404 children born between 2006 and 2011 (Environments for Healthy Living) with prospectively collected pre-natal, perinatal and follow-up data were linked to i) nationwide Medicare and pharmaceutical data and ii) Emergency Department (ED) data from four hospitals in Australia. Parental-reported allergy was assessed in those who returned follow-up questionnaires. ED presentation was defined as any presentation for a suite of allergic disorders, excluding asthma. Univariate analysis and multivariate logistic regression were used to descibe risk factors for both parental-reported allergy and ED presentation for an allergic disorder.

Results

The incidence of parental-reported child allergy at 1, 3 and 5 years of age was 7.8, 7.8 and 12.6%, respectively. Independent predictors of parental-report of allergy in multivariate analysis were parental-report of asthma (OR 2.2, 95% CI 1.4–3.4) or eczema (OR 4.3, 95% CI 3.1–6.1) and age > 6 months at introduction of solids (OR 1.3, 95% CI 1.0–1.7). Factors associated with ED presentations for allergy, which occurred in 3.6% of the cohort, were presence of maternal asthma (OR 2.3 95% CI:1.1, 4.9) and child born in spring (OR 1.7, 95% CI 1.1, 2.7).

Conclusions

More than 10% of children up to 5 years have a parental-reported allergic disorder, and 3.6% presented to ED. Parental-report of eczema and/or asthma and late introduction of solids were predictors of parental-report of allergy. Spring birth and maternal asthma were predictors for ED presentation for allergy.

Electronic supplementary material

The online version of this article (10.1186/s12887-018-1148-1) contains supplementary material, which is available to authorized users.

The MEGA Project: A Study of the Mechanisms Involved in the Genesis and Disease Course of Asthma. Asthma Cohort Creation and Long-Term Follow-Up

The general aim of this study is to create a cohort of asthma patients with varying grades of severity in order to gain greater insight into the mechanisms underlying the genesis and course of this disease. The specific objectives focus on various studies, including imaging, lung function, inflammation, and bronchial hyperresponsiveness, to determine the relevant events that characterize the asthma population, the long-term parameters that can determine changes in the severity of patients, and the treatments that influence disease progression. The study will also seek to identify the causes of exacerbations and how this affects the course of the disease. Patients will be contacted via the outpatient clinics of the 8 participating institutions under the auspices of the Spanish Respiratory Diseases Networking System (CIBER). In the inclusion visit, a standardized clinical history will be obtained, a clinical examination, including blood pressure, body mass index, complete respiratory function tests, and FENO will be performed, and the Asthma Control Test (ACT), Morisky-Green test, Asthma Quality of Life Questionnaire (Mini AQLQ), the Sino-Nasal Outcome Test 22 (SNOT-22), and the Hospital Anxiety and Depression scale (HADS) will be administered. A specific electronic database has been designed for data collection. Exhaled breath condensate, urine and blood samples will also be collected. Non-specific bronchial hyperresponsiveness testing with methacholine will be performed and an induced sputum sample will be collected at the beginning of the study and every 24 months. A skin prick test for airborne allergens and a chest CT will be performed at the beginning of the study and repeated every 5 years.

Asthma and atopic dermatitis after early-, late-, and post-term birth

OBJECTIVE

To assess the incidence and risk factors of asthma and atopic dermatitis by seven years of age after early-term (ET) (37⁺⁰ -38⁺⁶ weeks), full-term (FT) (39⁺⁰ -40⁺⁶ weeks), late-term (LT) (41⁺⁰ -41⁺⁶ weeks), and especially post-term (PT) (≥42 weeks) birth.

METHODS

Altogether, 965 203 infants born between 1991 and 2008 in Finland were investigated in ET, FT, LT, and PT groups. Data on asthma medication reimbursement and hospital visits for atopic dermatitis were retrieved from national health databases.

RESULTS

The frequencies of asthma medication reimbursement in the ET, FT, LT, and PT groups were 4.5%, 3.7%, 3.3%, and 3.2%, respectively. Hospital visits due to atopic dermatitis were most common after PT birth. Compared with FT births, ET births were associated with an increased risk of asthma (adjusted odds ratio (aOR), 95% confidence interval (CI) 1.20, 1.17-1.23), while LT (aOR, 95%CI 0.91, 0.89-0.93) births and PT (aOR, 95%CI 0.87, 0.83-0.92) births decreased this risk. PT birth (aOR, 95%CI 1.06, 1.01-1.10) predicted atopic dermatitis. From a population point of view, the most relevant risk factors for asthma were male sex, ET birth, smoking during pregnancy and birth by elective cesarean section, and for atopic dermatitis male sex, first delivery, birth in a level II hospital and birth by cesarean section.

CONCLUSIONS

Early-term birth was a predictor of asthma, and PT birth was associated with atopic dermatitis. Counseling against smoking and following strict indications for planned ET deliveries and cesarean sections may be means to reduce the risk of later asthma.

The effects of early life polyunsaturated fatty acids and ruminant trans fatty acids on allergic diseases: A systematic review and meta-analysis

Early life nutritional exposures could modify the gene expression and susceptibility of allergic diseases (AD). This systematic review aimed to evaluate whether early life (the first 1,000 days) natural exposure to polyunsaturated fatty acids (PUFA) and ruminant trans fatty acids (R-TFA) could affect the AD risk. We searched PubMed, EMBASE, PsycINFO, Scopus, the Cochrane Library, and ClinicalTrials.gov from inception through September 10, 2017 for relevant full-text articles in English. Observational studies were selected if they examined the effects of early life PUFA or R-TFA on AD (eczema, asthma, wheeze, and allergic rhinitis) or sensitization. The quality of studies was examined by the Newcastle-Ottawa Scale, and the best evidence synthesis (BES) was applied. We included 26 observational studies, and 8 of them showed high quality. BES showed a moderate evidence for the protective effect of vaccenic acid (VA, an R-TFA) on eczema, while insufficient or no evidence was found in other associations. Meta-analysis showed that higher n-6/n-3 ratio and linoleic acid were associated with higher risk of eczema (pooled odds ratio [OR] = 1.06, 95% confidence intervals [CI]: 1.00 -1.13; 1.08, 95% CI: 1.01 -1.15). However, VA was inversely associated with eczema pooled OR = 0.42, 95% CI: 0.25 -0.72). Early life natural exposure to VA showed evident benefit on decreasing the risk of eczema, while PUFA and other R-TFA showed limited effects on AD. More robust studies especially for R-TFA are required.

A Review of Autoimmune Disease Hypotheses with Introduction of the "Nucleolus" Hypothesis

Numerous hypotheses have been proposed in order to explain the complexity of autoimmune diseases. These hypotheses provide frameworks towards understanding the relations between triggers, autoantigen development, symptoms, and demographics. However, testing and refining these hypotheses are difficult tasks since autoimmune diseases have a potentially overwhelming number of variables due to the influence on autoimmune diseases from environmental factors, genetics, and epigenetics. Typically, the hypotheses are narrow in scope, for example, explaining the diseases in terms of genetics without defining detailed roles for environmental factors or epigenetics. Here, we present a brief review of the major hypotheses of autoimmune diseases including a new one related to the consequences of abnormal nucleolar interactions with chromatin, the "nucleolus" hypothesis which was originally termed the "inactive X chromosome and nucleolus nexus" hypothesis. Indeed, the dynamic nucleolus can expand as part of a cellular stress response and potentially engulf portions of chromatin, leading to disruption of the chromatin. The inactive X chromosome (a.k.a. the Barr body) is particularly vulnerable due to its close proximity to the nucleolus. In addition, the polyamines, present at high levels in the nucleolus, are also suspected of contributing to the development of autoantigens.