Maternal antibiotic exposure during pregnancy and the risk of allergic diseases in childhood: A meta-analysis

Children's food allergy: Effects of environmental influences and antibiotic use across critical developmental windows

BACKGROUND

Increasing studies linked outdoor air pollution (OAP), indoor environmental factors (IEFs), and antibiotics use (AU) with the first wave of allergies (i.e., asthma, allergic rhinitis, and eczema), yet the role of their exposures on children's second wave of allergy (i.e., food allergy) are unknown.

OBJECTIVES

To investigate the association between exposure to OAP and IEFs and childhood doctor-diagnosed food allergy (DFA) during the pre-pregnancy, prenatal, early postnatal, and current periods, and to further explore the effect of OAP and IEFs on DFA in children co-exposed to antibiotics.

METHODS

A retrospective cohort study involving 8689 preschoolers was carried out in Changsha, China. Data on the health outcomes, antibiotic use, and home environment of each child were collected through a questionnaire. Temperature and air pollutants data were obtained from 8 and 10 monitoring stations in Changsha, respectively. Exposure levels to temperature and air pollutants at individual home addresses were calculated by the inverse distance weighted (IDW) method. Multiple logistic regression models were employed to assess the associations of childhood DFA with exposure to OAP, IEF, and AU.

RESULTS

Childhood ever doctor-diagnosed food allergy (DFA) was linked to postnatal PM10 exposure with OR (95% CI) of 1.18 (1.03-1.36), especially for CO and O3 exposure during the first year with ORs (95% CI) = 1.08 (1.00-1.16) and 1.07 (1.00-1.14), as well as SO2 exposure during the previous year with OR (95% CI) of 1.13 (1.02-1.25). The role of postnatal air pollution is more important for the risk of egg, milk and other food allergies. Renovation-related IAP (new furniture) and dampness-related indoor allergens exposures throughout all time windows significantly increased the risk of childhood DFA, with ORs ranging from 1.23 (1.03-1.46) to 1.54 (1.29-1.83). Furthermore, smoke-related IAP (environmental tobacco smoke [ETS], parental and grandparental smoking) exposure during pregnancy, first year, and previous year was related to DFA. Additionally, exposure to pet-related indoor allergens (cats) during first year and total plant-related allergens (particularly nonflowering plants) during previous year were associated with DFA. Moreover, exposure to plant-related allergy during first and previous year was specifically associated with milk allergy, while keeping cats during first year increased the risk of fruits/vegetables allergy. Life-time and early-life AU was associated with the increased risk of childhood DFA with ORs (95% CI) = 1.57 (1.32-1.87) and 1.46 (1.27-1.67), including different types food allergies except fruit/vegetable allergy.

CONCLUSIONS

Postnatal OAP, life-time and early-life IEFs and AU exposure played a vital role in the development of DFA, supporting the "fetal origin of childhood FA" hypothesis.

Birthmode and environment-dependent microbiota transmission dynamics are complemented by breastfeeding during the first year

The composition and maturation of the early-life microbiota are modulated by a number of perinatal factors, whose interplay in relation to microbial vertical transmission remains inadequately elucidated. Using recent strain-tracking methodologies, we analyzed mother-to-infant microbiota transmission in two different birth environments: hospital-born (vaginal/cesarean) and home-born (vaginal) infants and their mothers. While delivery mode primarily explains initial compositional differences, place of birth impacts transmission timing-being early in homebirths and delayed in cesarean deliveries. Transmission patterns vary greatly across species and birth groups, yet certain species, like Bifidobacterium longum, are consistently vertically transmitted regardless of delivery setting. Strain-level analysis of B. longum highlights relevant and consistent subspecies replacement patterns mainly explained by breastfeeding practices, which drive changes in human milk oligosaccharide (HMO) degrading capabilities. Our findings highlight how delivery setting, breastfeeding duration, and other lifestyle preferences collectively shape vertical transmission, impacting infant gut colonization during early life.

Maternal-Fetal Exposure to Antibiotics: Levels, Mother-to-Child Transmission, and Potential Health Risks

Due to its widespread applications in various fields, antibiotics are continuously released into the environment and ultimately enter the human body through diverse routes. Meanwhile, the unreasonable use of antibiotics can also lead to a series of adverse outcomes. Pregnant women and developing fetuses are more susceptible to the influence of external chemicals than adults. The evaluation of antibiotic exposure levels through questionnaire surveys or prescriptions in medical records and biomonitoring-based data shows that antibiotics are frequently prescribed and used by pregnant women around the world. Antibiotics may be transmitted from mothers to their offspring through different pathways, which then adversely affect the health of offspring. However, there has been no comprehensive review on antibiotic exposure and mother-to-child transmission in pregnant women so far. Herein, we summarized the exposure levels of antibiotics in pregnant women and fetuses, the exposure routes of antibiotics to pregnant women, and related influencing factors. In addition, we scrutinized the potential mechanisms and factors influencing the transfer of antibiotics from mother to fetus through placental transmission, and explored the adverse effects of maternal antibiotic exposure on fetal growth and development, neonatal gut microbiota, and subsequent childhood health. Given the widespread use of antibiotics and the health threats posed by their exposure, it is necessary to comprehensively track antibiotics in pregnant women and fetuses in the future, and more in-depth biological studies are needed to reveal and verify the mechanisms of mother-to-child transmission, which is crucial for accurately quantifying and evaluating fetal health status.

[Risk factors for food allergy]

Allergy is the result of genetic and environmental interactions, including time, route, and dose of food exposure in susceptible patients. Risk factors can be: 1) genetic and 2) environmental, and these, in turn, are divided into prenatal, perinatal and postnatal. Food allergy appears frequently and depends on multiple risk factors (genetic and environmental), which in turn are divided into: prenatal, natal and postnatal factors; They participate in the expression of the disease and clinical intervention is not possible in all cases.

[Introduction to food allergy]

Food allergy is a common chronic disorder that affects infants, children, adolescents, and adults. The prevalence of food allergy has increased in recent decades throughout the world, not limited to Western countries. Since there is no treatment, this focuses on avoiding allergens, in addition to educating patients and caregivers in the emergency treatment of acute reactions, for example: application of epinephrine. Studies suggest that accidental reactions occur in about 45% of children with food allergies each year, although most reactions are mild or moderate in severity. Hospital admissions for food anaphylaxis vary from 4 to 20 per 100,000 inhabitants; Deaths are rare, with an estimated incidence of 0.03 to 0.3 per million people with food allergy. Death from food anaphylaxis is rare and appears to have remained stable, possibly due to increases in food allergen labeling, diagnostic services, rates of intramuscular epinephrine prescription, and awareness of food allergies. Omalizumab is a drug approved for several disorders (chronic hives or difficult asthma) and may help reduce symptoms associated with food allergy. The relative importance of alternative technologies, management strategies and policies for food allergy varies from one region to another, due to differences in the epidemiology, education, socioeconomic well-being, and cultural preferences of the population.

Association between antibiotic exposure and adverse outcomes of children and pregnant women: evidence from an umbrella review

BACKGROUND

Antibiotics are widely prescribed among children and pregnant women, but their safety profile is controversial. This study aimed to summarize and appraise current evidence for the potential impact of antibiotic exposure on pregnancy outcomes and children's health.

METHODS

PubMed, Embase, Web of Science and the Cochrane Database of Systematic Reviews were searched from inception to June 2022. Meta-analyses of any study design comparing the impact of antibiotic exposure with nonexposure among children, pregnant women and prepregnant women on adverse health outcomes of children and pregnancy were retrieved. The quality of evidence was assessed by a Measurement Tool to Assess Systematic Reviews 2 (AMSTAR2) and the Grading of Recommendations, Assessment, Development and Evaluation (GRADE). Data were reanalyzed, and the credibility of the evidence was determined.

RESULTS

Out of 2956 studies identified, 19 articles with 39 associations were included. Totally 19 of the associations (48.72%) were statistically significant with a P value ≤ 0.05, while only six were supported by highly suggestive evidence. Children with postnatal antibiotic exposure had a higher risk of developing asthma odds ratio (OR): 1.95, 95% confidence interval (CI): 1.76-2.17, wheezing (OR: 1.81, 95% CI 1.65-1.97) and allergic rhinoconjunctivitis (OR: 1.66, 95% CI 1.51-1.83), with prediction intervals excluding the nulls. Quality assessed by both AMSTAR2 and GRADE of included meta-analyses were very low in general.

CONCLUSIONS

Antibiotic exposure in early life was associated with children's long-term health, especially in cases of allergic diseases. Prenatal exposure might also influence children's health in some aspects but requires more high-quality evidence. Potential adverse effects of antibiotics on pregnancy outcomes were not observed in our study. Studies with higher quality and better quantification of antibiotic exposure are needed in the future.

Maternal antibiotic exposure and childhood allergies: The Japan Environment and Children's Study

Background

The association of maternal antibiotic exposure during pregnancy with childhood allergic diseases remains unclear.

Objective

We aimed to evaluate the association of maternal exposure to antibiotic use during pregnancy with childhood allergic diseases up to the age of 3 years by using data from a large Japanese birth cohort.

Methods

We analyzed data on 78,678 pregnant women and their offspring aged 0 to 3 years. Prenatal antibiotic exposure was defined as the use of any antimicrobial agent during pregnancy. Information was collected from maternal interviews and medical record transcripts. The outcome variables in this study included preschool asthma, wheezing, food allergy, atopic dermatitis, eczema, allergic rhinoconjunctivitis, and any allergic disease. We used logistic regression analysis to evaluate the association of antibiotic exposure during pregnancy with childhood allergic diseases.

Results

Among the participating mothers, 28.5% used antibiotics during pregnancy. Antibiotic exposure during pregnancy was associated with preschool asthma (adjusted odds ratio [aOR] = 1.12 [95% CI = 1.06-1.19]), wheezing (aOR = 1.11 [95% CI = 1.07-1.15]), allergic rhinoconjunctivitis (aOR = 1.10 [95% CI = 1.03-1.17]) and any allergic disease (aOR = 1.09 [95% CI = 1.05-1.14]) in offspring up to age 3 years. In contrast, maternal antibiotic use was not associated with food allergies, atopic dermatitis, or eczema. Additionally, the significant associations were not influenced by the timing of antibiotic exposure, sex of the infants, or maternal history of allergies.

Conclusion

Maternal antibiotic exposure during pregnancy is associated with an increased risk of childhood respiratory allergies.

Early-life risk factors for food allergy: Dietary and environmental factors revisited

There appears a steep increase in the prevalence of food allergy worldwide in the past few decades. It is believed that, rather than genetic factors, the recently altered dietary and environmental factors are the driving forces behind the rapid increase of this disease. Accumulating evidence has implied that external exposures that occurred in prenatal and postnatal periods could affect the development of oral tolerance in later life. Understanding the potential risk factors for food allergy would greatly benefit the progress of intervention and therapy. In this review, we present updated knowledge on the dietary and environmental risk factors in early life that have been shown to impact the development of food allergy. These predominantly include dietary habits, microbial exposures, allergen exposure routes, environmental pollutants, and so on. The key evidence, conflicts, and potential research topics of each theory are discussed, and associated interventional strategies to prevent the disease development and ameliorate treatment burden are included. Accumulating evidence has supported the causative role of certain dietary and environmental factors in the establishment of oral tolerance in early life, especially the time of introducing allergenic foods, skin barrier function, and microbial exposures. In addition to certain immunomodulatory factors, increasing interest is raised toward modern dietary patterns, where adequately powered studies are required to identify contributions of those modifiable risk factors. This review broadens our understanding of the connections between diet, environment, and early-life immunity, thus benefiting the progress of intervention and therapy of food allergy.

Influence of Lifestyle and Dietary Habits on the Prevalence of Food Allergies: A Scoping Review

Changes in behavior, lifestyle, and nutritional patterns have influenced many potential risk variables globally. In recent decades, food allergies (FAs) have been elevated to a severe public health issue both in developed countries and developing countries (third-world countries). This study aims to evaluate the effects caused by certain factors such as lifestyle and dietary habits on food allergies, review the association of lifestyle and dietary habit status with FAs, and outline why more people are allergic to food sources as a result of lifestyle changes and dietary habits. We searched electronic international databases including Scopus, PubMed, Google Scholar, and Web of Science using combinations of keywords. Utilizing Excel, the relevant studies were included and the irrelevant studies were excluded, and Mendeley was used for referencing and also to remove duplicates. The framework proposed by Arksey and O'Malley was used for this scoping review. The papers published in the databases from 2016 to 2020 were extracted. A total of eight studies were extracted, and this scoping review was carried out according to the risk factors. In our review, we found that some lifestyle choices (Caesarean section and antibiotics) and dietary habits (n-3 PUFA, fast food, duration of dietary intervention, and vitamin D), were important contributing factors for FA.

Antibiotic Use during Pregnancy in South Korea Using 2011-2020 National Health Insurance Claims Data

BACKGROUND

Since antimicrobial overuse and misuse can have substantial impacts on both public health and fetal well-being, it is essential to gain comprehensive insights into antimicrobial consumption patterns in pregnant women. This study aims to demonstrate antimicrobial utilization in pregnant women.

METHODS

We conducted a population-based cohort study using National Health Insurance claims data from January 2009 to December 2020 in South Korea. The target population was pregnancies in women aged 15-45 years who gave birth between 2011 and 2019. The outcome measure was the percentage of antibiotic prescriptions by trimester, subgroup, diagnostic category, and therapeutic category. Antibiotics were defined as J01 in the WHO ATC/DDD classification. To analyze the factors that influenced antibiotic prescriptions, we conducted multivariate logistic regression analysis.

RESULTS

Antibiotics were prescribed at least once in 1,808,588 (50%) of the 3,614,478 pregnancies. The proportion of deliveries with exposure to antibiotic therapy during pregnancy increased from 48% in 2011 to 54.8% in 2020. The prescription rate of antibiotics was highest in mothers younger than 25 years old, and it was lowest in participants aged 30-34 years. Also, antibiotic use was highest in the first trimester (30%) and lowest in the second trimester (18.2%). The most commonly used class was J01D (other beta-lactam antibacterials), which includes cephalosporins, and it accounted for 57% of the prescribed antibiotics. An increased probability of being prescribed antibiotics was associated with those younger than 25 years old, insurance (Medical Aid), hospitalization experience, an increase in physician visits, and comorbidities. For comorbidities, the OR was higher for respiratory tract infection (RTI), sexually transmitted infection, and urinary tract infection compared to those without disease, whereas it was decreased for diabetes and epilepsy.

CONCLUSION

The prescribing rate of antibiotics to pregnant women in South Korea has remained stably high. Also, an increase in the use of broad-spectrum beta-lactam penicillin was noted. It is necessary to monitor antibiotics in pregnant women generally in accordance with recommendations.

Antibiotics in pregnancy influence nasal microbiome and respiratory morbidity in infancy

Background

The effects of prenatal antibiotic exposure on respiratory morbidity in infancy and the involved mechanisms are still poorly understood. We aimed to examine whether prenatal antibiotic exposure in the third trimester is associated with nasal microbiome and respiratory morbidity in infancy and at school age, and whether this association with respiratory morbidity is mediated by the nasal microbiome.

Methods

We performed 16S ribosomal RNA gene sequencing (regions V3-V4) on nasal swabs obtained from 296 healthy term infants from the prospective Basel-Bern birth cohort (BILD) at age 4-6 weeks. Information about antibiotic exposure was derived from birth records and standardised interviews. Respiratory symptoms were assessed by weekly telephone interviews in the first year of life and a clinical visit at age 6 years. Structural equation modelling was used to test direct and indirect associations accounting for known risk factors.

Results

α-Diversity indices were lower in infants with antibiotic exposure compared to nonexposed infants (e.g. Shannon index p-value 0.006). Prenatal antibiotic exposure was also associated with a higher risk of any, as well as severe, respiratory symptoms in the first year of life (risk ratio 1.38, 95% CI 1.03-1.84; adjusted p-value (padj)=0.032 and risk ratio 1.75, 95% CI 1.02-2.97; padj=0.041, respectively), but not with wheeze or atopy in childhood. However, we found no indirect mediating effect of nasal microbiome explaining these clinical symptoms.

Conclusion

Prenatal antibiotic exposure was associated with lower diversity of nasal microbiome in infancy and, independently of microbiome, with respiratory morbidity in infancy, but not with symptoms later in life.

Maternal exposure to antibiotics and risk of atopic dermatitis in childhood: a systematic review and meta-analysis

Background

Although the association between maternal exposure to antibiotics and the risk of atopic dermatitis (AD) in childhood has been studied extensively, there still is a lack of clarity on the topic. The aim of this study was to summarize the published data and to examine if maternal exposure to antibiotics increases the risk of AD in childhood.

Methods

Systematic search was performed in PubMed, Scopus, Web of Science, and Embase for all types of studies on the review subject independent of any language restrictions and published up to 28th December 2022. Data was analyzed using random-effects model and presented as pooled odds ratio (OR) with 95% confidence intervals (CI).

Results

A total of 18 studies (5,354,282 mother-child pairs) were included. Maternal exposure to antibiotics was associated with an increased risk of AD in childhood (OR: 1.14, 95% CI: 1.06, 1.22, I²= 85%, p = 0.0003). The significance of the results was not affected by the location of the study (Asia or Europe). While subgroup analysis based on exposure assessment or diagnosis of AD demonstrated a tendency of increased risk of AD, the association was not statistically significant in multiple subgroups. Segregating data based on the timing of exposure did not affect the significance of the results for studies on all trimesters. However, there was no association between antibiotic exposure in the third trimester or just before delivery and the risk of childhood AD.

Conclusion

The results of this meta-analysis suggest that maternal exposure to antibiotics may lead to a modestly increased risk of AD in offspring. The evidence is limited by high interstudy heterogeneity and bias in exposure and outcome assessment. Future studies are needed to explore if the timing of exposure, the dose, the number of prescriptions, and the type of antibiotic affect this association.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42023387233.

Prenatal and early-life antibiotic exposure and the risk of atopic dermatitis in children: A nationwide population-based cohort study

BACKGROUND

Atopic dermatitis (AD) contributes to substantial social and financial costs in public health care systems. Antibiotic exposure during pregnancy has been proposed as a risk factor, but findings remain inconsistent. The aim of this study was to investigate the association between prenatal antibiotic use and childhood AD.

METHODS

We performed a population-based cohort study using data collected from the Taiwan Maternal and Child Health Database from 2009 to 2016. Associations were determined using Cox proportional hazards model and were adjusted for several potential covariates, including maternal atopic disorders and gestational infections. Children with and without maternal predispositions of atopic diseases and postnatal antibiotic/acetaminophen exposures within 1 year were stratified to identify the subgroups at risk.

RESULTS

A total of 1,288,343 mother-child pairs were identified and 39.5% received antibiotics prenatally. Maternal antibiotic use during pregnancy was slightly positively associated with childhood AD (aHR 1.04, 95% CI 1.03-1.05), especially in the first and second trimesters. An apparent dose-response pattern was observed with an 8% increased risk when the exposure was ≥5 courses prenatally (aHR 1.08, 95% CI 1.06-1.11). Subgroup analysis showed the positive association remained significant regardless of postnatal infant antibiotic use, but the risk attenuated to null in infants who were not exposed to acetaminophen (aHR 1.01, 95% CI 0.96-1.05). The associations were higher in children whose mothers were without AD compared to those whose mothers were with AD. In addition, postnatal antibiotic or acetaminophen exposure of infants was associated with an increased risk of developing AD after 1 year of age.

CONCLUSION

Maternal antibiotic use during pregnancy was associated with an increased risk of childhood AD in a dose-related manner. Further research may be warranted to investigate this variable using a prospectively designed study, and also to examine whether or not this association is specifically related to pregnancy.

Early life exposures and development of allergic disease in infants with familial risk: Results from ongoing probiotic intervention trials

AIM

We search revision of risk determinants of the ongoing allergy epidemic.

METHODS

Children numbering 433 born to mothers with allergic disease or sensitisation were selected from the three ongoing probiotic intervention trials for this case-control study. Children who developed atopic eczema or food allergy, had positive skinprick test results or had been prescribed inhaled corticosteroids by the age of 2 years were identified as cases (n = 231), while children without allergic manifestations were the healthy controls (n = 202). The data on early environmental exposures were collected from prospectively documented study records. The statistical analyses were adjusted for potential confounders.

RESULTS

Determinants associated with the increased risk of atopic eczema were lower maternal prepregnancy BMI (aOR 0.15, 95% CI: 0.037-0.54) and maternal intrapartum antibiotic treatment (aOR 2.21, 95% CI 1.20-4.10), the latter also linked to obstructive respiratory symptoms (aOR 3.87, 95% CI 1.07-14.06). The risk of allergic sensitisation was associated with lower maternal prepegnancy BMI (aOR 0.18, 95% CI 0.43-0.79) and intrapartum antibiotic treatment (aOR 2.13, 95% CI 1.07-4.22).

CONCLUSION

Based on our demonstrations, interventions such as personalised diets, can be optimised for specific subgroups and definite risk periods.

Human matters in asthma: Considering the microbiome in pulmonary health

Microbial communities form an important symbiotic ecosystem within humans and have direct effects on health and well-being. Numerous exogenous factors including airborne triggers, diet, and drugs impact these established, but fragile communities across the human lifespan. Crosstalk between the mucosal microbiota and the immune system as well as the gut-lung axis have direct correlations to immune bias that may promote chronic diseases like asthma. Asthma initiation and pathogenesis are multifaceted and complex with input from genetic, epigenetic, and environmental components. In this review, we summarize and discuss the role of the airway microbiome in asthma, and how the environment, diet and therapeutics impact this low biomass community of microorganisms. We also focus this review on the pediatric and Black populations as high-risk groups requiring special attention, emphasizing that the whole patient must be considered during treatment. Although new culture-independent techniques have been developed and are more accessible to researchers, the exact contribution the airway microbiome makes in asthma pathogenesis is not well understood. Understanding how the airway microbiome, as a living entity in the respiratory tract, participates in lung immunity during the development and progression of asthma may lead to critical new treatments for asthma, including population-targeted interventions, or even more effective administration of currently available therapeutics.

Early life environmental antibiotic exposure and preschool allergic diseases: A biomonitoring-based prospective study in eastern China

Background

Globally, the prevalence of allergic diseases remains high, as does the level of environmental antibiotics. It has been found that clinical antibiotic application may increase preschool allergy risk. However, few biomonitoring studies have been conducted about the association between early life environmental trace dose antibiotic exposure and preschool allergy.

Objective

To analyze the association between prenatal environmental antibiotic levels and allergic diseases using logistic regression models.

Methods

A total of 743 pregnant women and their offspring from the Shanghai Allergy Birth Cohort completed five years follow-up, and 251 mother-infant pairs were finally included. Maternal urine samples were collected for 15 antibiotic quantitative measurements using liquid chromatography-tandem mass spectrometry. The high-antibiotic group was defined as having at least half of antibiotics exceeding the median concentration. Allergic diseases were assessed by clinicians through clinical history, standardized questionnaires, and annual physical examinations until the age of five. Skin-prick-test (SPT) was performed at 5 years old.

Results

The incidence of allergic diseases was generally higher in the high-antibiotic than that in the low-antibiotic group. Compared to the low-comprehensive antibiotic group, children in the high-antibiotic group were weakly associated with allergic diseases but had a 6-fold increased risk of food allergens sensitivity (OR: 7.09, 95% CI: 1.59, 31.74). Association of above-median single prenatal antibiotic concentration exposure and allergic diseases was also observed (azithromycin and asthma, OR: 2.72, 95% CI: 1.15, 6.42; enrofloxacin and wheeze, OR: 2.22, 95% CI: 1.22, 4.05; trimethoprim and atopic dermatitis, OR: 2.00, 95% CI: 1.08, 3.71). Moreover, children with higher prenatal norfloxacin levels were more sensitive to food allergens (OR: 5.52, 95%CI: 1.54, 19.71).

Conclusion

Early-life environmental antibiotic exposure may be correlated with an increased risk of asthma, wheeze, atopic dermatitis, and SPT positivity for food allergens in 5-year-old children.

Associations between pre- and postnatal antibiotic exposures and early allergic outcomes: A population-based birth cohort study

BACKGROUND

Early life antibiotic treatment is one likely exposure influencing allergy risk. The objective was to investigate associations between pre- and postnatal antibiotic exposures and the development of allergic manifestations until age 18 months.

METHODS

We included 1387 mother-child dyads from the prospective, population-based NorthPop birth cohort study. Data on antibiotic exposures in pregnancy and childhood were collected by web-based questionnaires. Until the child turned 18 months old, parents (n = 1219) reported symptoms of wheeze, eczema, and physician-diagnosed asthma; parents (n = 1025) reported physician-diagnosed food allergy. At age 18 months, serum immunoglobulin E levels to inhalant (Phadiatop) and food (Food mix fx5) allergens were determined. Associations were estimated using bivariable and multivariable logistic regressions.

RESULTS

Prenatal antibiotic exposure was positively associated with food sensitization in the crude (OR 1.82, 95% CI 1.01-3.26) but not in the adjusted analyses (aOR 1.58, 0.82-3.05). A borderline significant association was found between prenatal exposure and wheeze (aOR 1.56, 0.95-2.57). Postnatal antibiotics were positively associated with wheeze (aOR 2.14, 1.47-3.11), asthma (aOR 2.35, 1.32-4.19), and eczema (aOR 1.49, 1.07-2.06). Postnatal antibiotics were negatively associated with food sensitization (aOR 0.46, 95% CI 0.25-0.83) but not with food allergy nor sensitization to inhalants.

CONCLUSION

Pre- and postnatal antibiotic exposure demonstrated positive associations with allergic manifestations and the former also with food sensitization. In contrast, there was a negative association between postnatal antibiotics and food sensitization. Food sensitization is often transient but may precede respiratory allergies. Future studies should investigate the relationship between antibiotic exposure and food sensitization later in childhood.

Maternal antibiotics disrupt microbiome, behavior, and temperature regulation in unexposed infant mice

Maternal antibiotic (ABx) exposure can significantly perturb the transfer of microbiota from mother to offspring, resulting in dysbiosis of potential relevance to neurodevelopmental disorders such as autism spectrum disorder (ASD). Studies in rodent models have found long-term neurobehavioral effects in offspring of ABx-treated dams, but ASD-relevant behavior during the early preweaning period has thus far been neglected. Here, we exposed C57BL/6J mouse dams to ABx (5 mg/ml neomycin, 1.25 μg/ml pimaricin, .075% v/v acetic acid) dissolved in drinking water from gestational day 12 through offspring postnatal day 14. A number of ASD-relevant behaviors were assayed in offspring, including ultrasonic vocalization (USV) production during maternal separation, group huddling in response to cold challenge, and olfactory-guided home orientation. In addition, we obtained measures of thermoregulatory competence in pups during and following behavioral testing. We found a number of behavioral differences in offspring of ABx-treated dams (e.g., modulation of USVs by pup weight, activity while huddling) and provide evidence that some of these behavioral effects can be related to thermoregulatory deficiencies, particularly at younger ages. Our results suggest not only that ABx can disrupt microbiomes, thermoregulation, and behavior, but that metabolic effects may confound the interpretation of behavioral differences observed after early-life ABx exposure.

Probiotics or synbiotics addition to sows’ diets alters colonic microbiome composition and metabolome profiles of offspring pigs

Little information exists about the effects of maternal probiotics and synbiotics addition on the gut microbiome and metabolome of offspring. The present study evaluated the effects of probiotics or synbiotics addition to sows’ diets on colonic microbiota and their metabolites in offspring using 16S rRNA gene sequencing and metabolome strategy. A total of 64 pregnant Bama mini-pigs were randomly divided into control, antibiotic, probiotics, and synbiotics groups and fed the corresponding experimental diets during pregnancy and lactation. After weaning, two piglets per litter and eight piglets per group were selected and fed a basal diet. The β-diversity analysis showed that the colonic microbiota of offspring had a clear distinction among the four groups at 65 days of age. Maternal probiotics addition increased the Actinobacteria abundance at 65 days of age and Tenericutes and Firmicutes abundances at 95 days of age of offspring compared with the other three groups, whereas maternal antibiotic addition increased Spirochaetes and Proteobacteria abundances at 95 days of age of offspring compared with the other three groups. Metabolomic analysis showed that colonic metabolites were different between the groups, regardless of the days of age. Furthermore, both PICRUSt2 and enrichment analysis of metabolic pathways showed that maternal probiotics and synbiotics addition affected metabolism of carbohydrate, amino acid, cofactors and vitamins in the colonic microbiota. Compared with the control group, the colonic concentration of indole decreased and skatole increased in the probiotics group, whereas indole increased and skatole decreased in the synbiotics group. Maternal probiotics addition increased the colonic concentrations of acetate and butyrate at 65 and 125 days of age, whereas probiotics and synbiotics addition decreased short-chain fatty acids concentrations at 95 days of age. In addition, the colonic concentrations of putrescine, cadaverine, 1,7-heptanediamine, and spermidine were increased in the antibiotic, probiotics, and synbiotics groups compared with the control group at 95 days of age. The correlation analysis showed that Gemmiger, Roseburia, and Faecalibacterium abundances were positively correlated with acetate, propionate, and butyrate concentrations; Gemmiger, Blautia, and Faecalibacterium were positively correlated with putrescine and spermidine; and Faecalibacterium, Blautia, Clostridium, and Streptococcus were positively correlated with (R)-3-hydroxybutyric acid. Collectively, these findings suggest that probiotics and synbiotics addition to sows’ diets exerts effects on offspring pigs by altering gut microbiota composition and their metabolites. The potential beneficial effect on gut health is discussed.

Does the timing of antibiotic exposure in pregnancy impact the risk of development of pediatric asthma?: A systematic review and meta-analysis

OBJECTIVE

Maternal exposure to antibiotics has been linked to the development of pediatric asthma. However, the impact of the timing of exposure is unclear. We aimed to explore if the risk of pediatric asthma varies with trimester-specific exposure to antibiotics through a systematic review and meta-analysis.

METHODS

PubMed, Embase, ScienceDirect, CENTRAL, and Google Scholar databases were searched for studies reporting an association between trimester-specific maternal exposure to antibiotics and risk of asthma in the offspring.

RESULTS

Eleven studies were included. The total sample size of the included studies was 2,160,216. Meta-analysis revealed a statistically significant increased risk of asthma with first (RR: 1.13 95% CI: 1.10, 1.17 I² = 59% p < 0.00001), second (RR: 1.14 95% CI: 1.07, 1.21 I² = 92% p < 0.0001), and third (RR: 1.14 95% CI: 1.08, 1.20 I²=86% p < 0.00001) trimester exposure of antibiotics. The results were stable on sensitivity analysis. On subgroup analysis, we noted that the association for the first and second trimester was significant for studies on children >5 years but not for those on children <5 years of age. The certainty of evidence based on GRADE was low.

CONCLUSION

Our results indicate that antibiotics administered during any trimester of pregnancy lead to an increased risk of childhood asthma. The overall risk is small and could be due to confounding. Further studies rigorously adjusting for important confounding variables are needed for stronger evidence.

Environmental antibiotics exposure in school-age children in Shanghai and health risk assessment: A population-based representative investigation

BACKGROUND

The widespread use of antibiotics has left extensive residues in the environment and food. Antibiotics can accumulate in human body. As the potential health risks of antibiotic exposure in children are of a great concern in recent years, our study aimed to describe the status of antibiotic exposure in primary school students in Shanghai, China, and to explore the relationships of dietary patterns with internal antibiotic levels.

METHODS

The Shanghai Children's Health, Education, and Lifestyle Evaluation (SCHEDULE) Survey was a cross-sectional study with a staged, cluster random sample of all primary school students in Shanghai, China. In the present study, we randomly selected 2199 children aged 6-12 years old. A total of 10 antibiotics in urine samples were measured by liquid chromatography-tandem mass spectrometry. Multivariable survey logistic regression models were used to investigate dietary patterns associated with detection rates of antibiotics.

RESULTS

The detection rates of individual antibiotics ranged from 4.3% to 30.7%. 68.7% of children were exposed to at least one antibiotic. There was a significant difference in child exposure to overall antibiotics by residential locations (60.9% in urban vs. 71.1% in suburban areas). Principal component analyses suggested that higher unhealthy dietary pattern scores were significantly associated with increased detection rates of tetracyclines [1.27 (95% CI: 1.18, 1.38)] and sulfonamides [1.20 (95% CI: 1.05, 1.36)]. In addition, 9.05% of children had a hazard index (HI) value greater than 1, which was mainly contributed by ciprofloxacin.

CONCLUSIONS

School-age children were widely exposed to antibiotics in Shanghai. Unhealthy diet was associated with a higher level of antibiotic exposure.

Maternal BMI and allergy in children until 3 years of age (JECS)

Background

Maternal prepregnancy body mass index (BMI) may influence allergic diseases in the children who are the product of those pregnancies.

Objective

The purpose of our study was to investigate the association between mothers' prepregnancy BMI and the risk of physician-diagnosed asthma, food allergy (FA), and atopic dermatitis (AD) in their children during the first 3 years of life.

Methods

Data on mothers' prepregnancy BMI and physician-diagnosed asthma, FA, and AD in their children until the age of 3 years were obtained from the Japan Environment and Children's Study, a nationwide birth cohort study that has recruited 103,099 pregnant women between 2011 and 2014. Logistic regression analysis was used to analyze the results.

Results

We analyzed 67,204 mother-child pairs with available information on physician-diagnosed allergic diseases. The risk of asthma was significantly higher in children born to overweight mothers (adjusted OR [aOR] =1.17 [95% CI = 1.07-1.28]) and obese mothers (aOR = 1.28 [95% CI = 1.08-1.50]), whereas the risk of FA, cow's milk allergy, and egg allergy decreased significantly in children born to overweight mothers (aOR = 0.84 [95% CI = 0.76-0.92]; aOR = 0.78 [95% CI = 0.64-0.93]; and aOR = 0.83 [95% CI = 0.74-0.94]) and obese mothers (aOR = 0.81 [95% CI = 0.67-0.97]; aOR = 0.58 [95% CI = 0.36-0.87]; and aOR = 0.73 [95% CI = 0.56-0.93]) compared with in children born to normal weight mothers, respectively. Associations between AD and maternal BMI were not detected.

Conclusion

Our study showed that an increase in mothers' prepregnancy BMI was associated with an increase in asthma prevalence and a decrease in FA prevalence in their children. Further studies are needed to reveal the mechanisms associated with maternal BMI and pediatric allergic diseases.

Effects of delivery mode and labor duration on the development of food sensitization in infancy

BACKGROUND

The effects of delivery mode and labor duration on the development of food sensitization (FS) in infancy remain unclear.

OBJECTIVE

To elucidate the potential effects of delivery mode and labor duration on FS development by 6 months of age.

METHODS

Using data from a randomized controlled trial of a birth cohort from 4 Japanese hospitals that assessed cow's milk allergy development by 6 months of age, we performed a nested case-control trial of 462 participants who had undergone the final assessment at 6 months of age. FS was defined as positive skin prick test reactions to hen's egg, cow's milk, wheat, or soy. For the primary outcome, we calculated the adjusted odds ratio of vaginal delivery (VD) relative to cesarean delivery for FS development by 6 months of age using a multivariable logistic regression analysis. For the secondary outcome, we compared labor durations between participants with and without FS using the Mann-Whitney U test.

RESULTS

The adjusted odds ratio of VD for FS development was 2.54 (95% confidence interval, 1.32-4.87; P = .005). The median labor duration was significantly longer in participants with FS (5.7 hours, interquartile range, 2.7-10.1) than in participants without FS (4.5 hours, 1.1-8.2) (P = .01).

CONCLUSION

VD was considerably associated with an increased risk of FS in infancy, and longer labor durations may promote FS development.

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.

Prepregnancy BMI, gestational weight gain and risk of childhood atopic dermatitis: A systematic review and meta-analysis

BACKGROUND

Maternal weight before and during pregnancy influences the health of offspring. Several observational studies have investigated a link between the risk of childhood atopic dermatitis (AD) and prepregnancy maternal body mass index (BMI) and gestational weight gain (GWG), but the conclusions of these studies were inconsistent. The aim of this review was to evaluate the association between the risk of childhood AD and prepregnancy maternal BMI and GWG.

METHODS

The PubMed, Embase, Cochrane, Web of Science, and Scopus databases were searched from inception to February 2, 2021. Observational studies investigating the association between the risk of childhood AD and prepregnancy maternal BMI and GWG were included. Fixed- or random-effects models with inverse variance weights were used to calculate pooled risk estimates. Subgroup analysis and sensitivity analysis were used to explore the sources of heterogeneity.

RESULTS

Thirteen studies with a total of 114 485 participants were included. Ten studies reported prepregnancy maternal BMI, and five reported GWG. Maternal underweight was associated with a higher risk of childhood AD (odds ratio [OR] = 1.06; 95% confidence interval [CI], 1.02-1.10). Continuous BMI was not related to childhood AD (OR = 1.00; 95% CI, 0.98-1.02). In comparison with normal GWG, moderate/very high GWG increased the risk of childhood AD (OR = 1.05; 95% CI, 1.02-1.08; OR = 1.13; 95% CI, 1.07-1.19, respectively), while low GWG decreased the risk (OR = 0.92; 95% CI, 0.89-0.96). Excessive GWG relative to recommendations was associated with a higher risk of childhood AD (OR = 1.05; 95% CI, 1.01-1.10), while a lower risk of childhood AD was associated with inadequate GWG relative to recommendations (OR = 0.87, 95% CI: 0.83-0.91).

CONCLUSIONS

Maternal underweight, high GWG, and excessive GWG relative to recommendations are associated with an elevated risk of childhood AD, while low GWG and inadequate GWG relative to recommendations decreased the risk. Weight management before and during pregnancy is encouraged for primary prevention of childhood AD.

Early life exposures and the risk of inflammatory bowel disease: Systematic review and meta-analyses

BACKGROUND

Early life exposures impact immune system development and therefore the risk of immune-mediated diseases, including inflammatory bowel disease (IBD). We systematically reviewed the impact of pre-, peri‑, and postnatal exposures up to the age of five years on subsequent IBD diagnosis.

METHODS

We identified case-control and cohort studies reporting on the association between early life environmental factors and Crohn's disease (CD), ulcerative colitis (UC), or IBD overall. Databases were search from their inception until May 24th, 2019 until July 14th, 2020. We conducted meta-analyses for quantitative review of relevant risk factors that were comparable across studies and qualitative synthesis of the literature for a wide range of early life exposures, including maternal health and exposures during pregnancy, perinatal factors, birth month and related-factors, breastfeeding, hygiene-related factors and social factors, immigration, antibiotics, offspring health, including infections, and passive smoking. PROSPERO registration: CRD42019134980.

FINDINGS

Prenatal exposure to antibiotics (OR 1.8; 95% CI 1.2-2.5) and tobacco smoke (OR 1.5; 95% CI 1.2-1.9), and early life otitis media (OR 2.1; 95% CI 1.2-3.6) were associated with IBD. There was a trend towards an association between exposure to antibiotics in infancy and IBD (OR: 1.7, 95% CI 0.97, 2.9), supported by positive data on population-based data. Breastfeeding was protective against IBD. Other early life risk factors had no association with IBD, but data were limited and heterogenous.

INTERPRETATION

Early life is an important period of susceptibility for IBD development later in life. Tobacco smoke, infections and antibiotics were associated positively, and breastfeeding was associated negatively with IBD. Our findings offer an opportunity to develop primary prevention strategies.

FUNDING

This study did not receive any funding.