Infection and antibiotic use in infancy and risk of childhood obesity: a longitudinal birth cohort study

Genetic predisposition to high BMI increases risk of early life respiratory infections and episodes of severe wheeze and asthma

BACKGROUND

High body mass index (BMI) is an established risk factor for asthma, but the underlying mechanisms remain unclear.

OBJECTIVE

To increase understanding of the BMI-asthma relationship by studying the association between genetic predisposition to higher BMI and asthma, infections and other asthma traits during childhood.

METHODS

Data were obtained from the two ongoing Copenhagen Prospective Studies on Asthma in Childhood (COPSAC) mother-child cohorts. Polygenic risk scores for adult BMI were calculated for each child. Replication was done in the large-scale register-based Integrative Psychiatric Research (iPSYCH) cohort using data on hospitalisation for asthma and infections.

RESULTS

In the COPSAC cohorts (n=974), the adult BMI polygenic risk score was significantly associated with lower respiratory tract infections (incidence rate ratio (IRR) 1.20, 95% CI 1.08-1.33, false discovery rate p-value (pFDR)=0.005) at age 0-3 years and episodes of severe wheeze (IRR 1.30, 95% CI 1.06-1.60, pFDR=0.04) at age 0-6 years. Lower respiratory tract infections partly mediated the association between the adult BMI polygenic risk score and severe wheeze (proportion mediated: 0.59, 95% CI 0.28-2.24, p-value associated with the average causal mediation effect (pACME)=2e-16). In contrast, these associations were not mediated through the child's current BMI and the polygenic risk score was not associated with an asthma diagnosis or reduced lung function up to age 18 years. The associations were replicated in iPSYCH (n=114 283), where the adult BMI polygenic risk score significantly increased the risk of hospitalisations for lower respiratory tract infections and wheeze or asthma throughout childhood to age 18 years.

CONCLUSION

Children with genetic predisposition to higher BMI had increased risk of lower respiratory tract infections and severe wheeze, independent of the child's current BMI. These results shed further light on the complex relationship between body mass BMI and asthma.

Implementation of a Multifaceted Program to Improve the Rational Use of Antibiotics in Children under 3 Years of Age in Primary Care

A multifaceted, participatory, open program based on a qualitative and quantitative approach was developed in the Region of Murcia (Spain) aimed to reduce antibiotic use in children under 3 years of age diagnosed with upper respiratory tract infections (acute otitis media, pharyngitis, and common cold). Antibiotic consumption was measured using the defined daily dose per 1000 inhabitants per day (DHD). Pre-intervention data showed a prevalence of antibiotic prescriptions in the primary care setting of 45.7% and a DHD of 19.05. In 2019, after the first year of implementation of the program, antibiotic consumption was 10.25 DHD with an overall decrease of 48% as compared with 2015. Although antibiotic consumption decreased in all health areas, there was a large variability in the magnitude of decreases across health areas (e.g., 12.97 vs. 4.77 DHD). The intervention program was effective in reducing the use of antibiotics in children under 3 years of age with common upper respiratory diseases, but reductions in antibiotic consumption were not consistent among all health areas involved.

Gut microbiota and childhood malnutrition: Understanding the link and exploring therapeutic interventions

Childhood malnutrition is a metabolic condition that affects the physical and mental well-being of children and leads to resultant disorders in maturity. The development of childhood malnutrition is influenced by a number of physiological and environmental factors including metabolic stress, infections, diet, genetic variables, and gut microbiota. The imbalanced gut microbiota is one of the main environmental risk factors that significantly influence host physiology and childhood malnutrition progression. In this review, we have evaluated the gut microbiota association with undernutrition and overnutrition in children, and then the quantitative and qualitative significance of gut dysbiosis in order to reveal the impact of gut microbiota modification using probiotics, prebiotics, synbiotics, postbiotics, fecal microbiota transplantation, and engineering biology methods as new therapeutic challenges in the management of disturbed energy homeostasis. Understanding the host-microbiota interaction and the remote regulation of other organs and pathways by gut microbiota can improve the effectiveness of new therapeutic approaches and mitigate the negative consequences of childhood malnutrition.

Obesity Heterogeneity by Neighborhood Context in a Largely Latinx Sample

Neighborhood socioeconomic context where Latinx children live may influence body weight status. Los Angeles County and Orange County of Southern California both are on the list of the top ten counties with the largest Latinx population in the USA. This heterogeneity allowed us to estimate differential impacts of neighborhood environment on children's body mass index z-scores by race/ethnicity using novel methods and a rich data source. We geocoded pediatric electronic medical record data from a predominantly Latinx sample and characterized neighborhoods into unique residential contexts using latent profile modeling techniques. We estimated multilevel linear regression models that adjust for comorbid conditions and found that a child's place of residence independently associates with higher body mass index z-scores. Interactions further reveal that Latinx children living in Middle-Class neighborhoods have higher BMI z-scores than Asian and Other Race children residing in the most disadvantaged communities. Our findings underscore the complex relationship between community racial/ethnic composition and neighborhood socioeconomic context on body weight status during childhood.

Association of Neonatal Antibiotic Exposure with Long-Term Growth Trajectory Faltering in Preterm-Birth Children

INTRODUCTION

Preterm neonates often receive a variety of duration of antibiotic exposure during admission. The aim of the study was to evaluate whether neonatal antibiotic exposure is relevant with longitudinal growth problems in preterm-birth children.

METHODS

This prospective study enrolled 481 infants who were born <32 weeks of gestation, discharged, and longitudinally followed from corrected age (CA) 6-60 months. After excluding 153 infants with blood culture-confirmed bacteremia, necrotizing enterocolitis, severe cerebral palsy, intestinal ostomy, and congenital anomaly, 328 infants were included for analysis. Covariates included perinatal demographics, neonatal morbidities, extrauterine growth restriction, and antibiotic exposure accumulated by term equivalent age. The primary outcome was the anthropometric trajectories in z-score of bodyweight (zBW), body height (zBH), and body mass index (zBMI) from CA 6-60 months.

RESULTS

Antibiotic exposure duration was significantly negatively associated with zBW and zBH at CA 6, 12, and 60 months, and zBMI at CA 60 months. Multivariate generalized estimating equation analyses showed antibiotic exposure duration had significantly faltering z-score increment from CA 6 to 60 months in zBW and zBH (adjusted mean [95% CI]; ΔzBW: -0.021 [-0.041 to -0.001], p = 0.042; ΔzBH: -0.019 [-0.035 to -0.002], p = 0.027) after adjustment. Children with neonatal antibiotic exposure duration >15 days were significantly lower in the mean anthropometric zBW, zBH, and zBMI at CA 6, 12, 24, and 60 months compared with children with neonatal antibiotic exposure ≤15 days (all p < 0.01).

CONCLUSIONS

Growth increments were negatively associated with antibiotic exposure duration in preterm neonates implicating that antibiotic stewardship and growth follow-up for preterm neonates are thus warranted.

Early-life exposure to antibiotics and excess body weight in childhood and adolescence: A systematic review and meta-analysis

BACKGROUND

The association between early-life exposure to antibiotics and overweight/obesity is unclear. We conducted a systematic review and meta-analysis to address this issue.

METHODS

We searched PubMed, Web of Science, Scopus, and grey literature from inception to August 10, 2022, for cohort studies investigating the association between early-life exposure to antibiotics and weight outcomes. Two independent reviewers screened studies for eligibility, extracted data, assessed risk of bias, and examined the certainty of the evidence. Random-effects meta-analyses was used for pooling the data. The review was registered in PROSPERO, CRD42021265417.

RESULTS

We included 42 studies and data from 28 of them were pooled in the quantitative synthesis. Overall antenatal (OR 1.10, 95% CI 1.04-1.16; 518,095 children, very low certainty) and second trimester (OR 1.11, 95% CI 1.08-1.14, 248,469 children, low certainty) exposure to antibiotics were associated with increased risk of overweight/obesity in childhood/adolescence. Overall early postnatal antibiotic exposure was also associated with increased likelihood of overweight/obesity in childhood/adolescence (OR 1.09, 95% CI 1.05-1.12, 1,488,316 children, very low certainty). The magnitude of the association increased from exposure to one (OR 1.07, 95% CI 1.00-1.15, 512,954 children) to four or more courses of antibiotics (OR 1.31, 95% CI 1.17-1.46, 543,627 children).

CONCLUSION

Antenatal and early postnatal exposure to antibiotics is associated increased likelihood of overweight/obesity, although the findings are limited by the very low certainty of evidence. We highlight the need for homogeneous prospective studies addressing potential confounding factors to further explore the link between exposure to antibiotics and the risk of excess body weight.

Gut microbiota and obesity: an overview of microbiota to microbial-based therapies

The increasing prevalence of obesity and overweight is a significant public concern throughout the world. Obesity is a complex disorder involving an excessive amount of body fat. It is not just a cosmetic concern. It is a medical challenge that increases the risk of other diseases and health circumstances, such as diabetes, heart disease, high blood pressure and certain cancers. Environmental and genetic factors are involved in obesity as a significant metabolic disorder along with diabetes. Gut microbiota (GM) has a high potential for energy harvesting from the diet. In the current review, we aim to consider the role of GM, gut dysbiosis and significant therapies to treat obesity. Dietary modifications, probiotics, prebiotics, synbiotics compounds, using faecal microbiota transplant, and other microbial-based therapies are the strategies to intervene in obesity reducing improvement. Each of these factors serves through various mechanisms including a variety of receptors and compounds to control body weight. Trial and animal investigations have indicated that GM can affect both sides of the energy-balancing equation; first, as an influencing factor for energy utilisation from the diet and also as an influencing factor that regulates the host genes and energy storage and expenditure. All the investigated articles declare the clear and inevitable role of GM in obesity. Overall, obesity and obesity-relevant metabolic disorders are characterised by specific modifications in the human microbiota's composition and functions. The emerging therapeutic methods display positive and promising effects; however, further research must be done to update and complete existing knowledge.

Early-Life Antibiotics and Childhood Obesity: Yeast Probiotics as a Strategy to Modulate Gut Microbiota

This study aimed to review the existing literature to investigate the potential link between early-life antibiotic use and being overweight or obese in children. PubMed, Web of Science, Embase, Google Scholar, and Cochrane Library were searched to identify studies published until August 2021 that assessed the relationship between early-childhood antibiotic use and measures of body mass index. The studies included children aged 0-18 years. Only cohort studies were taken into consideration. Studies published in languages other than English were excluded. Antibiotic usage in early life may increase the risk of obesity in children and the addition of yeast probiotics, such as Saccharomyces boulardii CNCM I 745, to antibiotic prescription can serve as a potential option to mitigate this risk.

Early-life antibiotic exposure increases the risk of childhood overweight and obesity in relation to dysbiosis of gut microbiota: a birth cohort study

Background

Early-life antibiotic exposure is associated with the development of later obesity through the disruption of gut microbiota in the animal models. However, the related epidemiological evidence is still conflicting.

Methods

A birth cohort was consisted of 2140 mother-infant pairs in Chaoyang District Maternal and Child Health Care Hospital in this study. Here, their available antibiotic exposure during the first one year of life was ascertained using a open-ended questionnaire and related anthropometric parameters from the health screening program. The compositions of gut microbiota were comprehensively analyzed by16S rRNA high throughput sequencing. Then the spearman correlations were performed by the multiple covariance-adjusted regressions between the antibiotic exposure with anthropometric parameters and compositions of gut microbiota.

Results

Among the 2140 subjects, the antibiotic exposure during the first one year of life was 53.04%, mainly by Cephalosporins (53.39%) and Erythromycins(27.67%) for the treatment of respiratory tract infection (79.56%), which were not significantly different among the subgroups. Compared to the control group, both childhood overweight and obesity at two and a half years were higher in the antibiotic exposed group, with higher percents of Faecalibacterium, Agathobacter and Klebsiella, and lower percentage of Bifidobacterium. Moreover, there were positively potential associations between early-life antibiotic exposure with the accelerated anthropometric parameters and disruption of Faecalibacterium, Agathobacter, Klebsiella and Bifidobacterium at two and a half years.

Conclusion

These above results proved that early-life antibiotic exposure was positively associated with the accelerated childhood overweight and obesity from one year to two and a half years by impacting the disorders of Faecalibacterium, Agathobacter, Klebsiella and Bifidobacterium, which would propose the theoretical basis for rationalizing the personalized antibiotic exposure among the infants to truly reflect the fairness of public health.

Supplementary information

The online version contains supplementary material available at 10.1186/s12941-022-00535-1.

Exploring the Potential of Human Milk and Formula Milk on Infants’ Gut and Health

Early-life gut microbiota plays a role in determining the health and risk of developing diseases in later life. Various perinatal factors have been shown to contribute to the development and establishment of infant gut microbiota. One of the important factors influencing the infant gut microbial colonization and composition is the mode of infant feeding. While infant formula milk has been designed to resemble human milk as much as possible, the gut microbiome of infants who receive formula milk differs from that of infants who are fed human milk. A diverse microbial population in human milk and the microbes seed the infant gut microbiome. Human milk contains nutritional components that promote infant growth and bioactive components, such as human milk oligosaccharides, lactoferrin, and immunoglobulins, which contribute to immunological development. In an attempt to encourage the formation of a healthy gut microbiome comparable to that of a breastfed infant, manufacturers often supplement infant formula with prebiotics or probiotics, which are known to have a bifidogenic effect and can modulate the immune system. This review aims to elucidate the roles of human milk and formula milk on infants’ gut and health.

Infections and antibiotic use in early life, and obesity in early childhood: a mediation analysis

BACKGROUND/OBJECTIVE

Literature shows a positive association between antibiotics and obesity in childhood, but fails to account for confounding by indication. We evaluate the direct effect of infection on obesity and the indirect effect mediated by antibiotics by performing a mediation analysis of the infection-obesity association.

METHODS

A Medicaid cohort of children age 2-14 years old between 2015-2019 (n = 61,330) is used to perform mediation analysis of infections and antibiotic use in the first year of life, and obesity in childhood in Missouri, U.S.A.

RESULTS

An additional infection increases the risk of obesity in childhood (aIRR = 1.050, p < 0.001); however, mediation by antibiotic use is clinically and statistically insignificant. If the number of infections is not considered in the analysis, then antibiotic use as a risk factor for obesity is overstated (aIRR = 1.037 vs. 1.013 p < 0.001).

CONCLUSIONS

The number of infections exhibits a significant relationship with obesity and is a stronger risk factor for obesity than antibiotic use. In particular, a greater number of bronchitis, otitis media, and upper respiratory infections in the first year of life are associated with a significant increased risk of obesity in childhood. We find only weak evidence that an additional antibiotics claim increases the risk of obesity in childhood and this risk may not be clinically meaningful. Further research is needed to explore the association between early childhood infections, especially in the first 6 months of life, and obesity including the biological mechanism and environmental factor of early life infections associated with obesity.

Obesogenic effect of erythromycin on Caenorhabditis elegans through over-eating and lipid metabolism disturbances

Environmental obesogens contributed significantly to the obesity prevalence. Recently, antibiotics joined the list of environmental obesogens, while the underlying mechanisms remained to be explored. In the present study, effects of erythromycin (ERY), one widely used macrolide antibiotic, were measured on C. elegans to investigate the obesogenic mechanism. Results showed that ERY at 0.1 μg/L significantly increased the fat content by 17.4% more than the control and also stimulated triacylglycerol (TAG) levels by 25.7% more than the control. Regarding the obesogenic mechanisms, ERY provoked over-eating by stimulation on the pharyngeal pumping and reduction on the satiety quiescence percentage and duration. Such effects were resulted from stimulation on the neurotransmitters including serotonin (5-HT), dopamine (DA) and acetylcholine (ACh). The nervous responses involved the up-regulation of Gsα (e.g., ser-7, gsa-1, acy-1 and kin-2) signaling pathway and the down-regulation of TGFβ (daf-7) but not via cGMP-dependent regulations (e.g., egl-4). Moreover, ERY stimulated the activities of fatty acid synthase (FAS) and glycerol-3-phosphateacyl transferases (GPAT) that catalyze lipogenesis, while ERY inhibited those of acyl-CoA synthetase (ACS), carnitine palmitoyl transferase (CPT) and acyl-CoA oxidase (ACO) that catalyze lipolysis. The unbalance between lipogenesis and lipolysis resulted in the fat accumulation which was consistent with up-regulation on mgl-1 and mgl-3 which are the down-steam of TGFβ regulation. Such consistence supported the close connection between nervous regulation and lipid metabolism. In addition, ERY also disturbed insulin which connects lipid with glucose in metabolism.

Influence of antibiotics given during labour and birth on body mass index z scores in children in the All Our Families pregnancy cohort

BACKGROUND/OBJECTIVES

Little is known about obesity risk associated with intrapartum antibiotic prophylaxis (IAP). Our objective was to determine if maternal antibiotic exposure during birth is associated with child body mass index (BMI) z scores in the first 3 years of life.

METHODS

In 2008 to 2010, 3388 pregnant women were recruited to the All Our Families study. Here, we included women with available data from obstetrical records on antibiotic use during birth (n = 1303) and children with at least one valid BMI z score (final sample n = 1262). The primary outcome was infant BMI z score at 1, 2 and 3 years of age.

RESULTS

IAP occurred in 432 of 1262 women. Children exposed to IAP had significantly higher mean [standard error (SE)] BMI z scores (1.071 [0.087] unit) at 1 year of age compared to non-exposed infants (0.744 [0.064] unit). Although the association was no longer significant after adjustment for confounding factors in the growth trajectory model, IAP resulted in a 0.255 unit increase in BMI z score at 1 year of age. Differences in BMI z score between exposed and non-exposed at baseline (year 1) only remained significant in sensitivity analysis.

CONCLUSION

The potential association between maternal IAP and increased infant BMI z score at 1 year of age should be confirmed in other cohorts and warrants investigation of interventions to mitigate this possible risk.

Antibiotic exposure and adverse long-term health outcomes in children: a systematic review and meta-analysis

BACKGROUND

Antibiotics are among the most commonly used drugs in children. In addition to inducing antibiotic resistance, antibiotic exposure has been associated with long-term adverse health outcomes.

METHODS

A systematic search using PRISMA Guidelines to identify original studies reporting associations between antibiotic exposure and long-term adverse health outcomes in children. Overall pooled estimates of the odds ratios (ORs) were obtained using fixed or random-effects models.

RESULTS

We identified 160 observational studies investigating 21 outcomes in 22,103,129 children. Antibiotic exposure was associated with an increased risk of atopic dermatitis (OR 1.40, 95% confidence interval (CI) 1.30-1.52, p<0.01), allergic symptoms (OR 1.93, 95%CI 1.66-2.26, p<0.01), food allergies (OR 1.35, 95%CI 1.20-1.52, p<0.01), allergic rhinoconjunctivitis (OR 1.66, 95%CI 1.51-1.83, p<0.01), wheezing (OR 1.81, 95%CI 1.65-1.97, p<0.01), asthma (OR 1.96, 95%CI 1.76-2.17, p<0.01), increased weight gain or overweight (OR 1.18, 95%CI 1.11-1.26, p<0.01), obesity (OR 1.21, 95%CI 1.05-1.40, p<0.01), juvenile idiopathic arthritis (OR 1.74, 95%CI 1.21-2.52, p<0.01), psoriasis (OR 1.75, 95%CI 1.44-2.11, p<0.01), autism spectrum disorders (OR 1.19, 95%CI 1.04-1.36, p=0.01) and neurodevelopment disorders (OR 1.29, 95%CI 1.09-1.53, p<0.01). Dose-response effects and stronger effects with broad-spectrum antibiotic were often reported. Antibiotic exposure was not associated with an altered risk of allergic sensitisation, infantile colic, abdominal pain, inflammatory bowel disease, celiac disease, type 1 diabetes, fluorosis, and attention deficit hyperactivity disorder.

CONCLUSION

Although a causal association cannot be determined from these studies, the results support the meticulous application of sound antibiotic stewardship to avoid potential adverse long-term health outcomes.

Prenatal and infant antibiotic exposure and childhood growth, obesity and cardiovascular risk factors: The Rhea mother-child cohort study, Crete, Greece

BACKGROUND

Early-life antibiotic use has been hypothesized to promote weight gain and increase the risk of childhood obesity.

OBJECTIVES

To examine the associations of prenatal and infant antibiotics with childhood growth, adiposity and cardiometabolic traits in the Greek Rhea cohort.

METHODS

We used data from 747 mother-child pairs with anthropometric measurements drawn from medical records or measured at 4 and 6 years of age. Antibiotic exposure was assessed by maternal report during pregnancy and at the first year of life. Children were classified as exposed to antibiotics prenatally if the mother received at least one course of oral antibiotics during pregnancy and postnatally if the mother reported that the child received at least one oral antibiotic treatment during the first year of life. Outcomes included repeated weight, body mass index (BMI), waist circumference, body fat (%), total cholesterol and blood pressure. We applied mixed effects, linear and log-binomial regression models after adjusting for important covariates.

RESULTS

Around 14.6% of the participating children were prenatally exposed to antibiotics and 32.4% received antibiotics during the first year of life. Prenatal exposure to antibiotics was associated with a twofold increase in the risk for obesity (risk ratio [RR]; 95% confidence interval [CI]: 2.09 [1.58, 2.76]) and abdominal obesity (RR [95% CI]: 2.56 [1.89, 3.47]) at 6 years. Postnatal exposure to antibiotics was associated with increased weight (beta [95% CI]: 00.25 [0.06, 0.44]) and BMI (beta [95% CI]: 0.23 [0.003, 0.45]) SD scores from 2 to 7 years of life.

CONCLUSION

Early-life antibiotic use was associated with accelerated childhood growth and higher adiposity.

Prenatal exposure to antibiotics and risk of childhood overweight or obesity: A systematic review and meta-analysis

Infant antibiotic use has been modestly associated with childhood overweight, while evidence on prenatal exposures remains less clear. A systematic review and meta-analysis were conducted to examine associations between maternal antibiotic exposure and subsequent risk of childhood overweight/obesity. Publications were retrieved from PubMed and Web of Science databases up to December 2019. A random effects model was used to summarize risk estimates, overall, and by period and frequency of exposure. Ten observational studies were included in the narrative synthesis. We did not observe a clear pattern of association between prenatal antibiotic use and childhood overweight/obesity. There were suggestive associations for repeated exposures (≥3 courses) and those taking place during the second trimester of gestation, which were also pointed out in our meta-analysis (relative risk, RR_2T  = 1.15 (95% CI 1.04; 1.28, I²  = 18%), and RR_3courses  = 1.31 (95% CI 1.03; 1.67, I²  = 65%), respectively). In most studies, however, confounding by underlying infections cannot be ruled out. Overall, current data do not conclusively support the hypothesis that prenatal exposure to antibiotics is a risk factor for childhood obesity/overweight. Further studies, controlling for underlying infections and exploring the association according to frequency, period (both prenatal and intrapartum) and type of antibiotic, are needed to clarify this association.

The association between living environmental factors and adolescents' body weight: a cross-sectional study

BACKGROUND

The effect of the living environment on public health has received increasingly scholarly attention. This study aims to explore the relationship between adolescents' body weight and their living environmental factors.

METHODS

This cross-sectional study comprised 1362 middle-school students from Nanjing and 826 from Changzhou in China. We further collected information on living environmental factors based on their home address and ran multivariate logistic regressions to explore potential correlations after considering a range of potential confounding factors.

RESULTS

Approximately 25% (n = 303) of students from Nanjing and 26% (n = 205) of students from Changzhou were excessive body weight. In Nanjing, students' BMI (Body Mass Index) showed a strong negative correlation with the number of sports venues in their neighborhood (Adjusted Odds Ratio (AOR): 0.64, 95%CI: 0.40-0.94) after controlling for other covariates. In Changzhou, we observed a positive correlation between adolescents' body weight and the number of bus stops in their neighbourhood (AOR:1.63, 95%CI:1.11-2.38).

CONCLUSIONS

The living environment factors were independently associated with teenagers' excessive body weight. We hypothesis that the environmental risk factors might be associated with political management, which will consequently affect personal health outcomes. Further research and proactive measures are required to manage those potential risks and attenuate the problem.

A Critical Review of Statistical Methods for Twin Studies Relating Exposure to Early Life Health Conditions

When investigating disease etiology, twin data provide a unique opportunity to control for confounding and disentangling the role of the human genome and exposome. However, using appropriate statistical methods is fundamental for exploiting such potential. We aimed to critically review the statistical approaches used in twin studies relating exposure to early life health conditions. We searched PubMed, Scopus, Web of Science, and Embase (2011–2021). We identified 32 studies and nine classes of methods. Five were conditional approaches (within-pair analyses): additive-common-erratic (ACE) models (11 studies), generalized linear mixed models (GLMMs, five studies), generalized linear models (GLMs) with fixed pair effects (four studies), within-pair difference analyses (three studies), and paired-sample tests (two studies). Four were marginal approaches (unpaired analyses): generalized estimating equations (GEE) models (five studies), GLMs with cluster-robust standard errors (six studies), GLMs (one study), and independent-sample tests (one study). ACE models are suitable for assessing heritability but require adaptations for binary outcomes and repeated measurements. Conditional models can adjust by design for shared confounders, and GLMMs are suitable for repeated measurements. Marginal models may lead to invalid inference. By highlighting the strengths and limitations of commonly applied statistical methods, this review may be helpful for researchers using twin designs.

Do Antibiotics Cause Obesity Through Long-term Alterations in the Gut Microbiome? A Review of Current Evidence

PURPOSE OF REVIEW

In this review, we summarize current evidence on the association between antibiotics and the subsequent development of obesity through modulation of the gut microbiome. Particular emphasis is given on (i) animal and human studies and their limitations; (ii) the reservoir of antibiotics in animal feed, emerging antibiotic resistance, gut dysbiosis, and obesity; (iii) the role of infections, specifically viral infections, as a cause of obesity; and (iv) the potential therapeutic approaches other than antibiotics to modulate gut microbiome.

RECENT FINDINGS

Overall, the majority of animal studies and meta-analyses of human studies on the association between antibiotics and subsequent development of obesity are suggestive of a link between exposure to antibiotics, particularly early exposure in life, and the development of subsequent obesity as a result of alterations in the diversity of gut microbiota. The evidence is strong in animal models whereas evidence in humans is inconclusive requiring well-designed, long-term longitudinal studies to examine this association. Based on recent meta-analyses and epidemiologic studies in healthy children, factors, such as the administration of antibiotics during the first 6 months of life, repeated exposure to antibiotics for ≥ 3 courses, treatment with broad-spectrum antibiotics, and male gender have been associated with increased odds of overweight/obesity. Early antibiotic exposure in animal models has shown that reductions in the population size of specific microbiota, such as Lactobacillus, Allobaculum, Rikenellaceae, and Candidatus Arthromitus, are related to subsequent adiposity. These data suggest that the loss of diversity of the gut microbiome, especially early in life, may have potential long-term detrimental effects on the adult host gut microbiome and metabolic health. Genetic, environmental, and age-related factors influence the gut microbiome throughout the lifetime. More large-scale, longer-term, longitudinal studies are needed to determine whether changes that occur in the microbiome after exposure to antibiotics, particularly early exposure, are causal of subsequent weight gain or consequent of weight gain in humans. Further well-designed, large-scale RCTs in humans are required to evaluate the effects of administration of antibiotics, particularly early administration, and the subsequent development of overweight/obesity. Therapeutic interventions, such as bacteriophage treatment or the use of probiotics, especially genetically engineered ones, need to be evaluated in terms of prevention and management of obesity.

Use of antibiotics during pregnancy is associated with infection in children at four years of age in Portugal

AIM

To assess the association between taking antibiotics in pregnancy and the occurrence of infections in children at four years of age.

METHODS

We studied children who participated in the follow-up of the birth cohort Generation XXI, Porto-Portugal, at the age of four years. We evaluated the associations between the use of antibiotics by the mother at any time in pregnancy with the occurrence of infections. Data were analysed using logistic regression, controlling for potential confounding variables.

RESULTS

We studied 7459 children (50.7% boys). The use of antibiotics at any stage of pregnancy, and not only in the third trimester, was associated with the occurrence of tonsillitis at four years, even after controlling for potential confounders (OR 1.19, 95% CI 1.03-1.38). Other infections did not show association.

CONCLUSION

Maternal use of antibiotics during pregnancy was associated with an increased risk of tonsillitis reported at four years of age. Antibiotics could favour the potential transmission of an unfavourable microbiome from mother to child.

Detection of antibiotics in the urine of children and pregnant women in Jiangsu, China

Exposure to low concentrations of antibiotics links to multiple health hazards, such as drug resistance of bacteria, and childhood obesity. In this study, seven antibiotics were measured in the urine of 107 children and 126 pregnant women in Jiangsu Province by ultra-performance liquid chromatography and tandem mass spectrometry (UPLC-MS/MS). The overall urinary antibiotics detection rate was 38.6%. Most (98.3%) of the participants' antibiotics concentrations were no more than 10 ng/mL. Children had a significantly higher detection rate than pregnant women (47.7% vs. 31.0%, P = 0.009), as well as the concentration (95th percentile: 6.49 vs. 4.08 ng/mL, P = 0.002). The detection rates of individual antibiotics ranged from 0.4% to 15.0%, and the concentrations ranged from lower than the limit of detection (LOD) through up to 31.96 ng/mL individually. Two or more antibiotics were detected in 11.2% of the urines. Tetracyclines were more frequently detected than phenicols (30.9% vs.12.4%). Oxytetracycline was the most frequently detected (15.0%). Multivariate logistic regression showed that consuming puffed food every day was associated with a significantly increased likelihood of detection, and higher concentration of overall antibiotics, and of doxycycline. Children were more likely to be detected of doxycycline and florfenicol, and to have elevated concentration of doxycycline, compared with pregnant women. This study highlights the relatively heavier antibiotics exposure in children, and a possible impact of puffed food on it, which needs to be warranted in future studies.

Gut dysbiosis during early life: causes, health outcomes, and amelioration via dietary intervention

The colonization and maturation of gut microbiota (GM) is a delicate and precise process, which continues to influence not only infancy and childhood but also adulthood health by affecting immunity. However, many perinatal factors, including gestational age, delivery mode, antibiotic administration, feeding mode, and environmental and maternal factors, can disturb this well-designed process, increasing the morbidity of various gut dysbiosis-related diseases, such as type-1-diabetes, allergies, necrotizing enterocolitis, and obesity. In this review, we discussed the early-life colonization and maturation of the GM, factors influencing this process, and diseases related to the disruption of this process. Moreover, we focused on discussing dietary interventions, including probiotics, oligosaccharides, nutritional supplementation, and exclusive enteral nutrition, in ameliorating early-life dysbiosis and diseases related to it. Furthermore, possible mechanisms, and shortcomings, as well as potential solutions to the drawbacks of dietary interventions, were also discussed.

Interaction between IgA and gut microbiota and its role in controlling metabolic syndrome

Immunoglobulin A (IgA) is the most abundant immunoglobulin isotype secreted into the mucosal tissues, mainly intestinal mucus. Humans can produce several grams of IgA every day, accounting for three quarters of the body's total immunoglobulin content. IgA, together with mucus and antimicrobial peptides, forms the first line of defence for intestinal epithelial cells, protecting them from a significant number of intestinal antigens. IgA also plays a principal role in controlling the gut microbiota (GM), and disruption in IgA can result in dysbiosis, such as the enrichment of Proteobacteria, which are generally bound by IgA. Proteobacteria overexpansion is also usually seen in obesity and colitis. Consistent with this, IgA dysfunction frequently results in metabolic syndrome (MetS), including conditions such as obesity, adiposity, insulin resistance, and inflammation. In contrast, enhanced IgA function can improve, and even prevent, MetS. Interactions among IgA, GM, and metabolism provide a promising avenue to combat MetS.

It's a rash: Antibiotic allergies in the modern era of antibiotic stewardship

OBJECTIVES

To determine whether current guidelines emphasizing antibiotic stewardship in pediatrics have been associated with reduced prevalence of antibiotic allergies in children severely affected by otitis media undergoing bilateral myringotomy with tympanostomy tube insertion (BMT) or by recurrent sinusitis or adenotonsillitis undergoing adenoidectomy with or without tonsillectomy.

METHODS

Case series of consecutive patients undergoing BMT or adenoidectomy with/without tonsillectomy for recurrent acute otitis media, recurrent sinusitis, or recurrent tonsillitis during November 2008 or November 2017 at a tertiary care children's hospital. Children with primarily obstructive indications for surgery, with prior tube placement or adenoidectomy, or with surgery by an outside provider were excluded. Demographics, type of surgery, and allergies or allergic symptoms were collected from the electronic medical record. Factors associated with antibiotic allergies were compared using logistic regression, Wilcoxon rank-sum, or Chi-squared test.

RESULTS

Seventy-five children who underwent surgery during 2008 and 75 children who underwent surgery in 2017 were included. Overall, median age at surgery was 3.24 years (range 0.56-17.49 years). Seventy-nine (52.7%) patients were female and 95 (63.3%) had private insurance. BMT was the most common surgery (82 children, 54.7%) followed by tonsillectomy with adenoidectomy (46 children, 30.7%), and adenoidectomy without tonsillectomy (39 children, 26.0%). Symptoms of allergic rhinitis were reported by 53 (35.3%) patients, and 11 (7.3%) and 5 (3.3%) had positive environmental and food allergy testing, respectively. Surprisingly, there was not a significant difference between the prevalence of antibiotic allergies in patients undergoing surgery during 2017 (17 patients, 22.7%) compared with 2008 (14 patients, 18.7%) (OR: 1.28, 95% CI: 0.578-2.82, p = 0.546). However, antibiotic allergies were less common in females (OR: 0.413, 95% CI: 0.182-0.937, p = 0.034) and more common in patients with a family history of antibiotic allergies (OR: 36.9, 95% CI: 5.12-∞, p < 0.001).

CONCLUSION

Pediatric otolaryngology surgical patients continue to exhibit a similar and high prevalence of antibiotic allergies in 2017 compared with 2008. Future studies are needed to determine whether this is because of overdiagnosis of antibiotic allergies or a failure of antibiotic guideline adherence to reduce antibiotic allergy prevalence.

Early childhood infections and body mass index in adolescence

BACKGROUND

The incidence of childhood overweight and obesity is rising. It is hypothesized that infections in early childhood are associated with being overweight. This study investigated the association between the number of symptomatic infections or antibiotic prescriptions in the first 3 years of life and body mass index (BMI) in adolescence.

SUBJECTS

The current study is part of the Prevention and Incidence of Asthma and Mite Allergy population-based birth cohort study. Weight and height were measured by trained research staff at ages 12 and 16 years. The 3015 active participants at age 18 years were asked for informed consent for general practitioner (GP) data collection and 1519 gave written informed consent. Studied exposures include (1) GP-diagnosed infections, (2) antibiotic prescriptions, and (3) parent-reported infections in the first 3 years of life. Generalized estimating equation analysis was used to determine the association between each of these exposures and BMI z-score.

RESULTS

Exposure data and BMI measurement in adolescence were available for 622 participants. The frequencies of GP-diagnosed infections and antibiotic prescriptions were not associated with BMI z-score in adolescence with estimates being 0.14 (95% CI -0.09-0.37) and 0.10 (95% CI -0.14-0.34) for the highest exposure categories, respectively. Having ≥6 parent-reported infections up to age 3 years was associated with a 0.23 (95% CI 0.01-0.44) higher BMI z-score compared to <2 parent-reported infections.

CONCLUSIONS

For all infectious disease measures an increase in BMI z-score for the highest childhood exposure to infectious disease was observed, although only statistically significant for parent-reported infections. These results do not show an evident link with infection severity, but suggest a possible cumulative effect of repeated symptomatic infections on overweight development.

Early Life Antibiotic Prescriptions and Weight Outcomes in Children 10 Years of Age

OBJECTIVE

We previously found that antibiotic use at <24 months of age was associated with slightly higher body weight at 5 years of age. In this study, we examine associations of early life antibiotic prescriptions with weight outcomes at 108 to 132 months of age ("10 years").

METHODS

We used electronic health record data from 2009 through 2016 from 10 health systems in PCORnet, a national distributed clinical research network. We examined associations of any (vs no) antibiotics at <24 months of age with body mass index z-score (BMI-z) at 10 years adjusted for confounders selected a priori. We further examined dose response (number of antibiotic episodes) and antibiotic spectrum (narrow and broad).

RESULTS

Among 56,727 included children, 57% received any antibiotics at <24 months; at 10 years, mean (standard deviation) BMI-z was 0.54 (1.14), and 36% had overweight or obesity. Any versus no antibiotic use at <24 months was associated with a slightly higher BMI-z at 10 years among children without a complex chronic condition (β 0.03; 95% confidence interval [CI] 0.01, 0.05) or with a complex chronic condition (β 0.09; 95% CI 0.03, 0.15). Any versus no antibiotic use was not associated with odds of overweight or obesity at 10 years among children without (odds ratio 1.02; 95% CI 0.97, 1.07) or with a complex chronic condition (odds ratio 1.07; 95% CI 0.96, 1.19).

CONCLUSIONS

The small and likely clinically insignificant associations in this study are consistent with our previous 5-year follow-up results, suggesting that, if this relationship is indeed causal, early increases in weight are small but maintained over time.

Role of IgA in the early-life establishment of the gut microbiota and immunity: Implications for constructing a healthy start

Colonization and maturation of the gut microbiota (GM) during early life is a landmark event that fundamentally influences the (early) immunity and later-life health of various mammals. This is a delicate, systematic process that is biologically actively regulated by infants and their mothers, where (secretory) IgA, an important regulator of microbes found in breast milk and generated actively by infants, may play a key role. By binding to microbes, IgA can inhibit or enhance their colonization, influence their gene expression, and regulate immune responses. IgA dysfunction during early life is associated with disrupted GM maturation and various microbe-related diseases, such as necrotizing enterocolitis and diarrhea, which can also have a lasting effect on GM and host health. This review discusses the process of early GM maturation and its interaction with immunity and the role of IgA (focusing on milk secretory IgA) in regulating this process. The possible application of this knowledge in promoting normal GM maturation processes and immune education has also been highlighted.

Association of Infant Antibiotic Exposure With Childhood Health Outcomes

OBJECTIVE

To investigate the extent to which antibiotic exposure in the first 2 years of life is associated with the risk of immunological, metabolic, and neurobehavioral health conditions with childhood onset.

PATIENTS AND METHODS

In this population-based cohort study, we identified all children born in Olmsted County, Minnesota, between January 1, 2003, and December 31, 2011, through the Rochester Epidemiology Project medical records-linkage system. Demographic characteristics, antibiotic prescriptions, and diagnostic codes through June 30, 2017, were retrieved using the Rochester Epidemiology Project infrastructure. Time-to-event analysis was performed to assess the impact of antibiotic exposure on the risk of several adverse health conditions.

RESULTS

This study included 14,572 children (7026 girls and 7546 boys), of whom 70% (10,220) received at least 1 antibiotic prescription during the first 2 years of life. Early antibiotic exposure was associated with an increased risk of childhood-onset asthma, allergic rhinitis, atopic dermatitis, celiac disease, overweight, obesity, and attention deficit hyperactivity disorder (hazard ratios ranging from 1.20 to 2.89; P<.05 for all). The associations were influenced by the number, type, and timing of antibiotic exposure. Moreover, children exposed to antibiotics had a higher probability of having combinations of conditions, particularly when given multiple prescriptions.

CONCLUSION

The present study finds significant associations between early life antibiotic exposure and several distinct health conditions with childhood onset. Additional research is warranted to establish practical guidelines to optimize the benefit and minimize the risk of antibiotics in children.

The impact of early life antibiotic use on atopic and metabolic disorders: Meta-analyses of recent insights

BACKGROUND AND OBJECTIVES

The impact of antibiotics use early in life on later-in-life morbidities has received substantial attention as explanations for atopic and metabolic disorders with a surge as modern lifestyle diseases. The objective of this study was to perform meta-analyses to determine if antibiotics administration during the first 2 years of infant life is associated with increased risks of atopic or metabolic disorders later in life.

METHODOLOGY

We screened more than 100 English-language prospective and retrospective studies published between January 2002 and March 2020 and assessed study quality using the Newcastle-Ottawa scale. We performed overall and subgroup meta-analyses on 31 high-quality comparable studies on atopic and 23 on metabolic disorders, involving more than 3.5 million children.

RESULTS

Antibiotic exposure prenatally and during the first 2 years of life significantly impacts the risk of developing atopic and metabolic disorders. Exposure during the first 6 months of life appears most critical, consistent with this being the time when the microbiome is most susceptible to irreversible perturbations. The presence of dose-response associations and stronger impacts of broad- than narrow-spectrum antibiotics further point to effects being mediated by microbiota-induced changes.

CONCLUSIONS AND IMPLICATIONS

Our findings support that antibiotics use is a mismatch to modernity that can negatively affect the symbiotic associations we rely on for proper immune function and metabolism. Improving our understanding of these associations, the underlying proximate mechanisms and the impact of antibiotics use on future human-symbiont evolution will be important to improve human health.

LAY SUMMARY

The use of antibiotics in infancy has been suggested to increase the risks of atopic and metabolic disorders later in life. Through meta-analyses of more than 100 studies of >3.5 million children, we confirm these risks, and show that patterns are consistent with effects being due to microbiota-driven changes.

Early and frequent exposure to antibiotics in children and the risk of obesity: systematic review and meta-analysis of observational studies

Background: This study aimed to systematically evaluate the available evidence on prenatal and early infancy antibiotic exposure and the association with overweight and obesity in later childhood.

Methods: We conducted a comprehensive search of Embase, MEDLINE, and Web of Science for observational studies assessing prenatal and early antibiotic exposure on the risk of overweight and obesity. We independently assessed the risk of bias using the ROBINS instrument and the overall quality of evidence using the GRADE approach.

Results: Our search identified thirteen observational studies including 554,983 participants; most studies were at moderate risk of bias. We found a statistically significant impact of early antibiotic exposure and the risk of being overweight later in childhood (OR 1.18; 95% CI 1.05 to 1.34) (very low quality evidence). We also found that early childhood antibiotic exposure was associated with the risk for childhood obesity (OR 1.14; 95% CI 1.04 to 1.24) (very low quality evidence).

Conclusions: Very low quality evidence suggests that exposure to antibiotics early in life may be associated with an increased risk of being overweight and obese in later childhood.  However, very low quality evidence raises serious questions about the plausibility of prenatal and early infancy antibiotic exposure being causally related to weight in children.

PROSPERO registration: CRD42016050011 (14/12/2016)

Strong association between adolescent obesity and consumption of macrolides in Europe and the USA: An ecological study

BACKGROUND

The reasons underpinning the large variations in the prevalence of childhood obesity are inadequately understood. Individual level studies have found that macrolide consumption at a young age increases the risk of subsequent obesity. We hypothesized that differences in population level consumption of macrolides may explain part of the variation in the prevalence of childhood obesity.

METHODS

Mixed effects beta regression was used to assess the association between the prevalence of childhood obesity in countries in Europe/ states in the United States and population level consumption of macrolides and total antibiotics. Different time lags between consumption and obesity measurement were used.

RESULTS

We found that in both the USA and Europe, population level consumption of macrolides was positively associated with subsequent childhood obesity prevalence. According to our model, the observed differences in population-level macrolide consumption in Europe/USA would translate into a 13%/72% higher odds of childhood obesity 5 years later. The association held regardless of the lag period used between exposure and outcome. The association with total antibiotic consumption was more equivocal.

CONCLUSIONS

Reducing macrolide consumption to that of low consumption countries may result in considerable reductions in childhood obesity.

Impact of Exposure to Antibiotics During Pregnancy and Infancy on Childhood Obesity: A Systematic Review and Meta-Analysis

OBJECTIVE

This study aimed to investigate whether antibiotic exposure during pregnancy and infancy was associated with childhood overweight or obesity.

METHODS

PubMed, Embase, and Cochrane Library databases were searched from the inception date to April 18, 2019, to identify observational studies that investigated the association between antibiotic exposure during pregnancy and infancy and childhood overweight or obesity. After study selection and data extraction, the meta-analysis was conducted using Stata software version 12.0 (StataCorp LP, College Station, Texas). The evaluation of the methodological quality was carried out by AMSTAR 2 (Bruyère Research Institute, Ottawa, Ontario, Canada).

RESULTS

A total of 23 observational studies involving 1,253,035 participants were included. The meta-analysis showed that prenatal exposure to antibiotics was not significantly associated with childhood overweight or obesity, whereas an increased risk of overweight or obesity was seen in subgroup analysis of the second trimester (risk ratio = 1.13; 95% CI: 1.06-1.22; P = 0.001). In contrast, antibiotic exposure during infancy could increase the risk of childhood overweight or obesity (risk ratio = 1.14; 95% CI: 1.06-1.23; P = 0.001).

CONCLUSIONS

This meta-analysis found that antibiotic exposure during the second trimester and infancy could increase the risk of childhood overweight or obesity.

Association of Repeated Antibiotic Exposure Up to Age 4 Years With Body Mass at Age 4.5 Years

IMPORTANCE

Antibiotic exposures in early life may affect weight by altering gut microbiota, potentially increasing the likelihood of childhood obesity.

OBJECTIVE

To examine whether repeated antibiotic exposure by age 48 months is associated with higher body mass index (BMI) at age 54 months.

DESIGN, SETTING, AND PARTICIPANTS

This research was undertaken within a prospective cohort study in New Zealand (Growing Up in New Zealand) that recruited 6853 children antenatally during 2009 to 2010. At the 54-month follow-up, 5734 of 6156 children (93%) had their weight and height measured. Community pharmacy antibiotic dispensing data were obtained from the New Zealand Pharmaceutical Collection database for children whose parents consented to external data linkage. The analytic sample comprised singletons with 54-month weight and height measurements, community antibiotic dispensing and birth weight data, gestational age greater than 27 weeks, and no congenital anomalies. Data analysis took place from 2017 to 2018.

EXPOSURES

Antibiotic exposure (yes or no), the number of dispensings, age at first exposure, and timing (age) of exposures between birth and age 48 months.

MAIN OUTCOMES AND MEASURES

World Health Organization BMI-for-age z scores; and International Obesity Task Force overweight and obesity cutoff points that pass through adult BMI values of 25 and 30.

RESULTS

Of the 5128 singletons (2622 [51%] male; mean [SD] birth weight of 3527 [542] g), 4886 (95%) had an antibiotic prescription by age 48 months and 437 (9%) had obesity at age 54 months. Adjusted mean (SE) BMI-for-age z scores increased significantly with the number of antibiotic dispensings for 4 to 6, 7 to 9, and more than 9 dispensings (unexposed, 0.87 [0.09]; 1-3 exposures, 0.92 [0.06] [P = .57]; 4-6 exposures, 1.06 [0.06] [P = .02]; 7-9 exposures, 1.06 [0.06] [P = .02]; >9 exposures, 1.08 [0.05] [P = .01]). Additionally, receiving more than 9 dispensings was associated with greater likelihood of obesity compared with no exposure (adjusted odds ratio, 2.41; 95% CI, 1.07-5.41). Children whose exposure began in the first year of life had a higher adjusted mean (SD) BMI-for-age z score than those not exposed (1.06 [0.05] vs 0.89 [0.09]; P = .03), whereas those whose exposure commenced after the first year of life did not (1.02 [0.06] vs 0.89 [0.09]; P = .10).

CONCLUSIONS AND RELEVANCE

In this study, repeated antibiotic exposure in early childhood was associated with higher mean BMI-for-age z score and an increased likelihood of obesity. Future research could examine whether interventions such as antibiotic stewardship programs, which are designed to reduce overprescribing of antibiotics, also reduce early childhood obesity.

Associations of Prenatal and Childhood Antibiotic Exposure With Obesity at Age 4 Years

Importance

Although antibiotics are associated with obesity in animal models, the evidence in humans is conflicting.

Objective

To assess whether antibiotic exposure during pregnancy and/or early childhood is associated with the development of childhood obesity, focusing particularly on siblings and twins.

Design, Setting, and Participants

This cross-sectional national study included 284 211 participants (132 852 mothers and 151 359 children) in New Zealand. Data analyses were performed for 150 699 children for whom data were available, 30 696 siblings, and 4188 twins using covariate-adjusted analyses, and for 6249 siblings and 522 twins with discordant outcomes using fixed-effects analyses. Data analysis was performed November 2017 to March 2019.

Exposure

Exposure to antibiotics during pregnancy and/or early childhood.

Main Outcomes and Measures

The main outcome is odds of obesity at age 4 years. Anthropometric data from children born between July 2008 and June 2011 were obtained from the B4 School Check, a national health screening program that records the height and weight of 4-year-old children in New Zealand. These data were linked to antibiotics (pharmaceutical records) dispensed to women before conception and during all 3 trimesters of pregnancy and to their children from birth until age 2 years.

Results

The overall study population consisted of 132 852 mothers and 151 359 children (77 610 [51.3%] boys) who were aged 4 to 5 years when their anthropometrical measurements were assessed. Antibiotic exposure was common, with at least 1 course dispensed to 35.7% of mothers during pregnancy and 82.3% of children during the first 2 years of life. Results from covariate-adjusted analyses showed that both prenatal and early childhood exposures to antibiotics were independently associated with obesity at age 4 years, in a dose-dependent manner. Every additional course of antibiotics dispensed to the mothers yielded an adjusted odds ratio (aOR) of obesity in their children (siblings) of 1.02 (95% CI, 0.99-1.06), which was similar to the odds across pregnancy for the whole population (aOR, 1.06; 95% CI, 1.04-1.07). For the child's exposure, the aOR for the association between antibiotic exposure and obesity was 1.04 (95% CI, 1.03-1.05) among siblings and 1.05 (95% CI, 1.02-1.09) among twins. However, fixed-effects analyses of siblings and twins showed no associations between antibiotic exposure and obesity, with aORs of 0.95 (95% CI, 0.90-1.00) for maternal exposure, 1.02 (95% CI, 0.99-1.04) for child's exposure, and 0.91 (95% CI, 0.81-1.02) for twins' exposure.

Conclusions and Relevance

Although covariate-adjusted analyses demonstrated an association between antibiotic exposure and odds of obesity, further analyses of siblings and twins with discordant outcomes showed no associations. Thus, these discordant results likely reflect unmeasured confounding factors.

The relationship of prenatal and infant antibiotic exposure with childhood overweight and obesity: a systematic review

This study aimed to assess the evidence regarding the relationship between early-life antibiotic exposure and childhood overweight/obesity by reviewing observational studies on prenatal antibiotic exposure and systematic reviews on infant antibiotic exposure. A search in Pubmed, Embase and Google Scholar covering the period 1st January till 1st December 2018 led to the identification of five studies on prenatal antibiotic exposure and four systematic reviews on infant antibiotic exposure. Positive trends between prenatal antibiotic exposure and overweight/obesity were reported in all studies; two studies reported a significant overall relationship and the other three reported significant relationships under certain conditions. Effect sizes ranged from odds ratio (OR): 1.04 (0.62-1.74) to relative risk (RR): 1.77 (1.25-2.51). Regarding infant antibiotics, one review concluded there was substantial evidence that infant antibiotic exposure increased the risk of childhood overweight/obesity [pooled effect sizes: RR: 1.21 (1.09-1.33) for overweight and RR: 1.18 (1.12-1.25) for obesity]. Two reviews concluded there was some evidence for a relationship [pooled effect sizes: OR: 1.05 (1.00-1.11) and OR: 1.11 (1.02-1.20)]. The fourth review concluded the studies were too heterogeneous for meta-analyses and the evidence regarding the relationship between infant antibiotic exposure and childhood overweight/obesity was inconclusive. More well-designed studies are needed that include data on intra-partum antibiotics and address important potential confounders (including maternal and childhood infections). This review points to some evidence of a relationship between early-life antibiotic exposure and childhood overweight/obesity; this is especially evident in certain children (i.e. exposed to multiple and broad-spectrum antibiotics, earlier postnatal exposure and male gender) and merits further research.

Association between early life (prenatal and postnatal) antibiotic administration and coeliac disease: a systematic review

OBJECTIVE

Whether prenatal or postnatal exposure to antibiotics is associated with an increased risk of coeliac disease (CD) is unclear. We systematically reviewed studies on the association between early life antibiotic exposure and the risk of CD or CD autoimmunity.

DESIGN

Systematic review of observational studies.

DATA SOURCES

The PubMed and Embase databases were searched up to December 2018, with no language restrictions. Additional references were obtained from reviewed articles.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Cohort, cross-sectional and case-control studies that assessed the association between prenatal and/or postnatal antibiotic exposure and the odds of developing CD (as defined by authors of the original studies) or CD autoimmunity were eligible for inclusion.

RESULTS

Six studies were included. In two large cohort studies that focused on prenatal antibiotic exposure, no association with the risk of CD was found (adjusted OR=1.16; 95% CI 0.94 to 1.43 and adjusted HR=1.33; 95% CI 0.69 to 2.56) in the Norwegian and Swedish cohorts, respectively. In three studies that evaluated the association of postnatal antibiotic exposure with the risk of CD, the results were contradictory, with only the Italian cohort study reporting a significant positive association (adjusted incidence rate ratio=1.24; 95% CI 1.07 to 1.43). A large, multicentre cohort study that evaluated the association between postnatal antibiotic exposure and CD autoimmunity in human leukocyte antigen (HLA)-positive subjects found no association.

CONCLUSIONS

We found no evidence of an association between prenatal or postnatal antibiotic exposure and CD.

Uso temprano de antibióticos en la infancia y obesidad pediátrica: revisión sistemática de la literatura

Introducción: la prevalencia de obesidad en el mundo es creciente y específicamente la obesidad en niños se ha convertido en un problema de salud pública que preocupa a varios países. La evidencia ha señalado al uso de antibióticos en la infancia como un factor relacionado con la presencia de obesidad infantil.Objetivo: Analizar sistemáticamente la evidencia reciente acerca de la relación entre el uso temprano de antibióticos en la infancia y la presencia de obesidad infantil.Métodos: Se realizó una búsqueda bibliográfica en las bases de Pubmed, Ovid, EBSCO, Lilacs, JAMA pediatrics de estudios observacionales en los últimos diez años que abordaran la relación entre el uso de antibióticos antes de los 24 meses de edad y la obesidad infantil.Resultados: Luego de realizar el tamizaje de los artículos, se seleccionaron 9 para la síntesis cualitativa. Con dos excepciones, los estudios analizados muestran una relación estadísticamente significativa entre el uso temprano de antibióticos y la obesidad o sobrepeso infantil, medido como peso para la edad o mediante el índice de masa corporal y aún con el ajuste por las potenciales variables de confusión, esta asociación permanece siendo estadísticamente significativa, debido a algunos de los diseños epidemiológicos, no se puede verificar la relación de antecedencia temporal de la exposición. 

Antibiotic use during pregnancy and childhood overweight: A population-based nationwide cohort study

Studies in mice suggest that early life represents a critical time window, where antibiotics may exert profound and lasting effects on the gut microbiota and metabolism. We aimed to test the hypothesis that prenatal antibiotic exposure is associated with increased risk of childhood overweight in a population-based cohort study. We linked 43,365 mother-child dyads from a nationwide cohort of pregnant women and their offspring to the Danish National Prescription Registry. Linear and logistic regression models were used to examine associations between prenatal exposure to antibiotics and BMI z-score and overweight (including obesity) at age seven and 11 years. Prenatal antibiotic exposure and childhood overweight were both associated with high pre-pregnancy BMI, maternal diabetes, multi-parity, smoking, low socioeconomic status, high paternal BMI, and short duration of breastfeeding. After adjustment for confounders, no associations were observed between prenatal antibiotic exposure and odds of overweight at age seven and 11 years. Whereas no association was observed between broad-spectrum antibiotics and overweight at age 11 years, exposure to broad-spectrum antibiotics was associated with higher odds of overweight at age seven years with an odds ratio of 1.27 (95% CI, 1.05–1.53) for ampicillin and an odds ratio of 1.56 (95% CI, 1.23–1.97) for amoxicillin. As we did not account for underlying infections, the observed associations with early childhood overweight could be explained by confounding by indication. In conclusion, our population-based study suggests that prenatal exposure to narrow-spectrum antibiotics is not associated with overweight in offspring. Exposure to some broad-spectrum antibiotics may increase the odds of overweight in early childhood, but the association does not persist in later childhood.

Antibiotic use in early childhood and risk of obesity: longitudinal analysis of a national cohort

BACKGROUND

Taking oral antibiotics during childhood has been linked with an increased risk of childhood obesity. This study assessed any potential association in number of courses of antibiotics taken between 2-3 and 4-5 years of age and body mass trajectory up to age 5.

METHODS

The study was a secondary analysis of 8186 children and their parents from the infant cohort of the Irish National Longitudinal Study of Children. Antibiotic use was measured by parental recall between ages 2-3 and 4-5. Longitudinal models described the relationship between antibiotic exposure and body mass index (BMI) standard deviation scores and binary outcomes, and examined interactions between covariates, which included socioeconomic status, diet assessed by food frequency questionnaires and maternal BMI.

RESULTS

Any antibiotic usage between 2 and 3 years did not predict risk of overweight or obesity at age 5. Four or more courses of antibiotics between 2 and 3 years were independently associated with obesity at age 5 (odds ratio 1.6, 95% confidence interval 1.11-2.31). Effect size was modest (coefficient + 0.09 body mass SD units, standard error 0.04, P = 0.037). Maternal BMI modified the relationship: ≥ 4 courses of antibiotics between 2 and 3 years were associated with a + 0.12 body mass SD units increase in weight at age 5 among children of normal-weight mothers (P = 0.035), but not in children of overweight mothers.

CONCLUSIONS

Number of antibiotic courses, rather than antibiotic use, may be an important factor in any link between early antibiotic exposure and subsequent childhood obesity. Research is needed to confirm differential effects on babies of normal versus overweight/obese mothers independent of socioeconomic factors.

A comprehensive diagnostic approach to detect underlying causes of obesity in adults

Obesity is a worldwide growing problem. When confronted with obesity, many health care providers focus on direct treatment of the consequences of adiposity. We plead for adequate diagnostics first, followed by an individualized treatment. We provide experience-based and evidence-based practical recommendations (illustrated by clinical examples), to detect potential underlying diseases and contributing factors. Adult patients consulting a doctor for weight gain or obesity should first be clinically assessed for underlying diseases, such as monogenetic or syndromic obesity, hypothyroidism, (cyclic) Cushing syndrome, polycystic ovarian syndrome (PCOS), hypogonadism, growth hormone deficiency, and hypothalamic obesity. The most important alarm symptoms for genetic obesity are early onset obesity, dysmorphic features/congenital malformations with or without intellectual deficit, behavioral problems, hyperphagia, and/or striking family history. Importantly, also common contributing factors to weight gain should be investigated, including medication (mainly psychiatric drugs, (local) corticosteroids, insulin, and specific β-adrenergic receptor blockers), sleeping habits and quality, crash diets and yoyo-effect, smoking cessation, and alcoholism. Other associated conditions include mental factors such as chronic stress or binge-eating disorder and depression.Identifying and optimizing the underlying diseases, contributing factors, and other associated conditions may not only result in more effective and personalized treatment but could also reduce the social stigma for patients with obesity.

Association between early antibiotic exposure and risk of childhood weight gain and obesity: a systematic review and meta-analysis

Background Recent studies have shown that antibiotic exposure during infancy is associated with increased body mass in healthy children. This study was performed to investigate the association between early-life antibiotic exposure and risk of childhood obesity. Methods A systematic review and meta-analysis was performed to comprehensively and quantitatively determine the association between early antibiotic exposure and risk of childhood obesity. Various databases such as PubMed, Embase, Scopus, Web of Science, ProQuest, Cochrane and Google Scholar were searched. A random-effects meta-analysis was performed to pool the statistical estimates. Additionally, a subgroup analysis was performed based on the time of follow-up. Results Nineteen studies involving at least 671,681 participants were finally included. Antibiotic exposure in early life was significantly associated with risk of childhood weight gain and obesity (odds ratio [OR]: 1.05, 95% confidence interval [CI]: 1.04-1.06). Conclusions Antibiotic exposure in early life significantly increases the risk of childhood weight gain and obesity.

Chronic antibiotic use during adulthood and weight change in the Sister Study

BACKGROUND/OBJECTIVES

Antibiotic use in early life has been associated with weight gain in several populations. However, associations between chronic antibiotic use and weight among adults in the general population are unknown.

SUBJECTS/METHODS

The NIEHS Sister Study is a longitudinal cohort of sisters of women with breast cancer. We examined associations between chronic antibiotic use (≥ 3 months) during the fourth decade of life (30-39 years) and subsequent obesity at enrollment (mean age = 55) via logistic regression. We also examined associations between chronic antibiotic use in the 5 years and 12 months prior to enrollment and weight gain after enrollment in linear mixed models. Models were adjusted for race/ethnicity, education, urban/rural status, age, and smoking.

RESULTS

In adjusted analyses (n = 50,237), chronic penicillin use during the 4th decade of life was associated with obesity at enrollment (OR 2.00, 95% CI 1.40, 2.87), and use in the 5 years prior to enrollment was associated with increased BMI change after enrollment (β 1.00 95% CI 0.01, 2.00). Use of bactericidals (OR 1.71, 95% CI 1.29, 2.26) during the 4th decade of life was also associated with obesity at enrollment. Associations for penicillins and bactericidals were consistent across indications for use. Bacteriostatic use in the 5 years prior to enrollment was associated with a reduction in BMI after enrollment (β -0.52, 95% CI -1.04, 0.00), and tetracycline use during the 4th decade of life was associated with reduced odds of obesity at enrollment (OR 0.72, 95% CI 0.56, 0.92). However, these inverse associations were only present for those who reported taking antibiotics for skin purposes. Cephalosporins, macrolides, quinolones, and sulfonamides were not associated with BMI change over time.

CONCLUSIONS

Chronic use of antibiotics during adulthood may have long-lasting impacts on BMI. Associations may differ by antibiotic class, and confounding by indication may be important for some antibiotic classes.

Predictors of becoming overweight among pediatric patients at risk for urinary tract infections

BACKGROUND

The association between obesity and urinary dysfunction in childhood has been described, albeit through retrospective analysis, making temporal relationships difficult to establish.

OBJECTIVE

The objective of this study was to determine risk factors for significant weight gain in children at risk for recurrent urinary tract infections.

STUDY DESIGN

A secondary analysis of the Randomized Intervention for Children with Vesicoureteral Reflux and Careful Urinary Tract Infection Evaluation trials was conducted. The outcome of interest in these children was significant increase in body mass index (BMI) percentile (>85th BMI percentile for sex and age) in previously normal-weight children. Multivariable logistic regression was used to determine the independent effects of predetermined risk factors.

RESULTS

In total, 446 patients were included in the study. Most patients aged less than 1 year at study entry (229, 51%), and 399 (89%) of patients were female. Eighty-four patients (17%) became clinically overweight. Patients assigned to prophylactic antibiotics were not more likely to gain significant BMI percentiles (adjusted odds ratio [aOR] = 1.1, 95% confidence interval [CI]=0.6-1.8). Significant BMI percentiles were gained in Hispanic/Latino patients compared with whites (aOR = 3.3, 95% CI=1.7-6.4), in children who were infants at study enrollment compared with non-infants (aOR = 2.1, 95% CI=1.2-3.8), and in those with persistent reflux during the study period (aOR = 2.1, 95% CI=1.0-4.3). Neither patients assigned to prophylactic antibiotics (aOR = 1.1, 95% CI=0.6-1.8) nor patients with bladder and bowel dysfunction (BBD) (aOR = 1.2, 95% CI=0.6-2.3) were more likely to gain significant BMI percentiles.

DISCUSSION

Significant BMI percentile gain is common in patients at risk for UTIs. Hispanic/Latino ethnicity, persistent reflux, and younger age, specifically infants than non-infants, were identified as independent risk factors for becoming overweight in this population. Exposure to prophylactic antibiotics and BBD were not associated with becoming overweight.

CONCLUSION

Risk for becoming overweight should be discussed when managing patients at risk for UTIs, especially in the subpopulations identified.

Early Antibiotics and Childhood Obesity: Do Future Risks Matter to Parents and Physicians?

To understand how parents and physicians make decisions regarding antibiotics and whether a potential associated risk of obesity would alter decisions, we conducted a qualitative study of parents and physicians who care for children. Parent focus groups and physician interviews used a guide focused on experience with antibiotics and perceptions of risks and benefits, including obesity. Content analysis was used to understand how a risk of obesity would influence antibiotic decisions. Most parents (n = 59) and physicians (n = 22) reported limited discussion about any risks at the time of antibiotic prescriptions. With an acute illness, most parents prioritized symptomatic improvement and chose to start antibiotics. Physicians' treatment preferences were varied. An obesity risk did not change most parents' or physicians' preferences. Given that parent-physician discussion at the time of acute illness is unlikely to change preferences, public health messaging may be a more successful approach to counter obesity and antibiotics overuse.

Early Antibiotic Exposure and Weight Outcomes in Young Children

: media-1vid110.1542/5839981580001PEDS-VA_2018-0290Video Abstract OBJECTIVES: To determine the association of antibiotic use with weight outcomes in a large cohort of children.

METHODS

Health care data were available from 2009 to 2016 for 35 institutions participating in the National Patient-Centered Clinical Research Network. Participant inclusion required same-day height and weight measurements at 0 to <12, 12 to <30, and 48 to <72 months of age. We assessed the association between any antibiotic use at <24 months of age with BMI z score and overweight or obesity prevalence at 48 to <72 months (5 years) of age, with secondary assessments of antibiotic spectrum and age-period exposures. We included children with and without complex chronic conditions.

RESULTS

Among 1 792 849 children with a same-day height and weight measurement at <12 months of age, 362 550 were eligible for the cohort. One-half of children (52%) were boys, 27% were African American, 18% were Hispanic, and 58% received ≥1 antibiotic prescription at <24 months of age. At 5 years, the mean BMI z score was 0.40 (SD 1.19), and 28% of children had overweight or obesity. In adjusted models for children without a complex chronic condition at 5 years, we estimated a higher mean BMI z score by 0.04 (95% confidence interval [CI] 0.03 to 0.05) and higher odds of overweight or obesity (odds ratio 1.05; 95% CI 1.03 to 1.07) associated with obtaining any (versus no) antibiotics at <24 months.

CONCLUSIONS

Antibiotic use at <24 months of age was associated with a slightly higher body weight at 5 years of age.

What exposures in early life are risk factors for childhood obesity?

Globally, estimates show that 41 million children younger than 5 years of age are affected by overweight and obesity. In many regions of the world, these prevalence rates have increased dramatically, especially in low- and middle-income countries, making childhood obesity a global policy issue. Recent data show that many children are already affected by overweight or obesity by the time they start school; hence, the examination of early exposures, with interventions around these exposures, is warranted. In this review, we outline the main modifiable exposures in early life that can lead to an increased risk of obesity. These exposures can be broadly categorised into parental factors such as obesity and gestational diabetes; dietary exposures in early life, including breastfeeding and complementary feeding and feeding behaviours; physical activity, sedentary behaviours and sleep; and environmental exposures such as maternal exposure to tobacco. We also identify research gaps and opportunities for further research.

The association between antibiotic use in infancy and childhood overweight or obesity: a systematic review and meta-analysis

PURPOSE

Antibiotic use is associated with alteration of the gut microbiome and metabolic activity. As childhood obesity is a predisposing factor for adult obesity, addressing childhood risk factors to weight gain in early life is important. This review aims to investigate the association between infant antibiotic exposure (aged < 24 months) and childhood obesity or overweight.

METHODS

Articles were retrieved from CINAHL, Cochrane CENTRAL, Embase and MEDLINE. Eligible articles investigated antibiotic use in exposed versus unexposed infants and measured childhood weight change. Data were synthesized narratively and meta-analysed where possible.

RESULTS

After title/abstract and full-text screening, 17 articles representing 15 unique studies were included for narrative synthesis. We found a small association between antibiotic exposure in infancy (<24 months) and childhood overweight or obesity. The strongest associations were observed in boys versus girls and children exposed to multiple antibiotic courses or broad-spectrum drugs. Meta-analysis of 12 sets of results comparing the earliest age of exposure to any antibiotic with overweight or obesity at the latest age of outcome found a pooled odds ratio of 1.05 (95% confidence interval: 1.00-1.11).

CONCLUSIONS

Antibiotic exposure in infants, aged < 24 months, was associated with a small increase in odds of childhood overweight or obesity in some subgroups of children.

Association between early life antibiotic use and childhood overweight and obesity: a narrative review

Background

Recent research implicates antibiotic use as a potential contributor to child obesity risk. In this narrative review, we examine current observational evidence on the relation between antibiotic use in early childhood and subsequent measures of child body mass.

Methods

We searched PubMed, Web of Science and the Cochrane Library to identify studies that assessed antibiotic exposure before 3 years of age and subsequent measures of body mass or risk of overweight or obesity in childhood.

Results

We identified 13 studies published before October 2017, based on a total of 6 81 332 individuals, which examined the relation between early life antibiotic exposure and measures of child body mass. Most studies did not appropriately account for confounding by indication for antibiotic use. Overall, we found no consistent and conclusive evidence of associations between early life antibiotic use and later child body mass [minimum overall adjusted odds ratio (aOR) reported: 1.01, 95% confidence interval (95% CI) 0.98-1.04, N = 2 60 556; maximum overall aOR reported: 2.56, 95% CI 1.36-4.79, N = 616], with no clinically meaningful increases in weight reported (maximum increase: 1.50 kg at 15 years of age). Notable methodological differences between studies, including variable measures of association and inclusion of confounders, limited more comprehensive interpretations.

Conclusions

Evidence to date is insufficient to indicate that antibiotic use is an important risk factor for child obesity, or leads to clinically important differences in weight. Further comparable studies using routine clinical data may help clarify this association.