Antibiotic treatment during infancy and increased body mass index in boys: an international cross-sectional study

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.

Testosterone disruptor effect and gut microbiome perturbation in mice: Early life exposure to doxycycline

Veterinary tetracyclines drugs are emerging organic pollutants detected at high concentrations in the urine of school children and a potential public health risk. However, the implications of early-life exposure to tetracyclines on testosterone production, being new endocrine disruptors, remain unknown. We investigated whether the early-life exposure to low-doxycycline, a widely used tetracycline, on mitochondria dysfunction and testosterone disruption in Leydig cells in vitro and in vivo. Next, we determined the mRNA levels of testis cells markers for early-life exposure to low-doxycycline outcomes of testis health in later-life. Finally, we compared the weight gain performance exposed to low- and therapeutic-doses through 15 weeks and examined the role of the microbiota during development. Our results showed doxycycline disturbed steroidogenesis process by mitochondrial dysfunction in mouse Leydig tumor cell line (MLTC-1) cells in vitro. Leydig cells mitochondrial function was disrupted by early-life exposure to low-doxycycline from birth to 49 days, causing testosterone deficiency and decreased quality of the sperm in mice. Early-life exposure to low-doxycycline significantly altered the mRNA levels of key genes in Leydig cells (Cyp11a1, Cyp17a1 and 17β-HSD) and spermatogenic cells (Grfal, Plzf, and Stra8) in later-life in mice. Subchronic low- and therapeutic-doses doxycycline changed gut microbiota differences in diversity reduction and compositional alteration. Moreover, the weight gain effects of doxycycline were only observed in low-dose in male mice. Overall, these results provide insight into the effects of doxycycline on both testis and gut microbiota health. The results provide insight that environmental antibiotics are needed additional research to classify as ECDs.

Probiotics in the next-generation sequencing era

Technological developments, including massively parallel DNA sequencing, gnotobiotics, metabolomics, RNA sequencing and culturomics, have markedly propelled the field of microbiome research in recent years. These methodologies can be harnessed to improve our in-depth mechanistic understanding of basic concepts related to consumption of probiotics, including their rules of engagement with the indigenous microbiome and impacts on the human host. We have recently demonstrated that even during probiotic supplementation, resident gut bacteria in a subset of individuals resist the mucosal presence of probiotic strains, limiting their modulatory effect on the microbiome and on the host gut transcriptional landscape. Resistance is partly alleviated by antibiotics treatment, which enables probiotics to interact with the host at the gut mucosal interface, although rather than promoting reconstitution of the indigenous microbiome and of the host transcriptional profile, they inhibit these components from returning to their naïve pre-antibiotic configurations. In this commentary, we discuss our findings in the context of previous and recent works, and suggest that incorporating the state-of-the-art methods currently utilized in microbiome research into the field of probiotics may lead to improved understanding of their mechanisms of activity, as well as their efficacy and long-term safety.

Investigating Caesarean Section Birth as a Risk Factor for Childhood Overweight

BACKGROUND

Caesarean section birth may be associated with overweight in childhood; however, findings to date have been inconsistent. This study explored the association of caesarean section vs. vaginal birth with childhood overweight in Vietnam.

METHODS

This longitudinal cohort study explored the association of delivery mode with overweight, obesity, and overweight/or obesity at 8 years of age in children (n = 1937) across 20 sites in Vietnam, using Young Lives longitudinal cohort study data. Categories were defined using BMI z-scores in relationship to the World Health Organization (WHO) reference median: overweight >1 and <2 standard deviations (SD) above WHO reference median, obese >2 SD, and overweight/or obese >1 SD. Individual questionnaire data collected sociodemographic information and pregnancy/birth information through face-to-face interviews with mothers/caregivers. Anthropometric measurements for mother and child were collected at baseline and at 8 years for children.

RESULTS

Adjusted multivariable logistic models revealed a twofold increase in odds at age 8 years of overweight [odds ratio (OR) = 1.8, 95% confidence interval (95% CI) 1.03-3.2, p = 0.039], obese (OR = 2.2, 95% CI 1.2-4.0, p = 0.014), or overweight/or obese (OR = 2.1, 95% CI 1.3-3.3, p = 0.002) for children born through caesarean section compared with vaginal birth. Children born through planned caesarean section (adjusted OR = 2.3, 95% CI 1.2-4.1, p < 0.001) and unplanned caesarean section (adjusted OR = 1.9, 95% CI 1.1-3.5, p = 0.03) had similar increased odds of overweight/or obesity compared with children born through vaginal birth.

CONCLUSIONS

These findings suggest that there may be an association between caesarean section and childhood overweight even after adjustment for confounders. Further research is needed to explore the underlying mechanisms of this finding.

Microbial Population Changes and Their Relationship with Human Health and Disease

Specific microbial profiles and changes in intestinal microbiota have been widely demonstrated to be associated with the pathogenesis of a number of extra-intestinal (obesity and metabolic syndrome) and intestinal (inflammatory bowel disease) diseases as well as other metabolic disorders, such as non-alcoholic fatty liver disease and type 2 diabetes. Thus, maintaining a healthy gut ecosystem could aid in avoiding the early onset and development of these diseases. Furthermore, it is mandatory to evaluate the alterations in the microbiota associated with pathophysiological conditions and how to counteract them to restore intestinal homeostasis. This review highlights and critically discusses recent literature focused on identifying changes in and developing gut microbiota-targeted interventions (probiotics, prebiotics, diet, and fecal microbiota transplantation, among others) for the above-mentioned pathologies. We also discuss future directions and promising approaches to counteract unhealthy alterations in the gut microbiota. Altogether, we conclude that research in this field is currently in its infancy, which may be due to the large number of factors that can elicit such alterations, the variety of related pathologies, and the heterogeneity of the population involved. Further research on the effects of probiotics, prebiotics, or fecal transplantations on the composition of the human gut microbiome is necessary.

The association between antibiotics in the first year of life and child growth trajectory

BACKGROUND

Antibiotics are frequently prescribed to children, and may be an environmental influence that contributes to the increasing prevalence of childhood obesity. The aim of this study was to examine the effect of antibiotic use in the first year of life on child growth trajectories from birth to age 6 years including significant covariates.

METHODS

Data from 586 children in the Infant Feeding Practices II (IFPS II) and 6 year follow-up study (6YFU) were included. Antibiotic exposures, weight and height measurements were collected from birth through the first 12 months, and then again at 6 years. Linear mixed effects growth modeling, controlling for exclusive breastfeeding, socio-demographic factors, smoking during pregnancy, gestational diabetes, and maternal pre-pregnancy weight status, was used to examine the association between antibiotic exposure and child growth trajectories through age 6 years.

RESULTS

The majority of infants (60.58%) did not receive any antibiotics; 33.79% received 1-2 courses and 5.63% received 3 or more antibiotic courses during the first year. In the unadjusted model, children with 1-2 antibiotic exposures had a 0.17 (SE 0.08) higher rate of change in BMI z-score (BMIz) than children without any antibiotics, and children with ≥3 exposures had a 0.42 (SE 0.16) higher rate of change in BMIz (p = 0.009). Growth trajectory over time for those who had ≥3 antibiotics was greater than those without any antibiotics (p = 0.002).

CONCLUSIONS

Efforts to guide the judicious use of antibiotics should continue, particularly in the first year of life.

Childhood infection, antibiotic exposure and subsequent metabolic risk in adolescent and young adult Aboriginal Australians: practical implications

There is now evidence linking antibiotic burden in infancy and subsequent risk factors for cardiometabolic disease. In this study we assessed the metabolic health of a community-based cohort of Aboriginal Australians aged 15-25 years and retrospectively examined their early childhood antibiotic burden to identify a possible link between the two. Metabolic health data were extracted from electronic files of 433 participants in prior Young Persons Checks between 2013 and 2016. More than one-third were overweight or obese. Males had more metabolic syndrome than females (20.6% vs 10%; P=0.03). Metabolic syndrome was twice as common in the 20- to 25-year age group than in the 15- to 19-year age group (19.8% vs 9.7%; P<0.001). A subsequent medical chart review focused on childhood infections and the antibiotic burden of participants in the Young Persons Check from birth to 15 years of age. Nearly 75% were prescribed antibiotics during their first 2 years of life and 29% were exposed four or more times. Childhood antibiotic burden decreased with age. This population of Aboriginal adolescents and young adults has high rates of antibiotic exposure in childhood and metabolic abnormalities. We did not find a correlation between the two within the cohort, potentially demonstrating a ceiling effect.

Prescription of Antibacterial Drugs for HIV-Exposed, Uninfected Infants, Malawi, 2004-2010

Antimicrobial drug resistance is a serious health hazard driven by overuse. Administration of antimicrobial drugs to HIV-exposed, uninfected infants, a population that is growing and at high risk for infection, is poorly studied. We therefore analyzed factors associated with antibacterial drug administration to HIV-exposed, uninfected infants during their first year of life. Our study population was 2,152 HIV-exposed, uninfected infants enrolled in the Breastfeeding, Antiretrovirals and Nutrition study in Lilongwe, Malawi, during 2004-2010. All infants were breastfed through 28 weeks of age. Antibacterial drugs were prescribed frequently (to 80% of infants), and most (67%) of the 5,329 prescriptions were for respiratory indications. Most commonly prescribed were penicillins (43%) and sulfonamides (23%). Factors associated with lower hazard for antibacterial drug prescription included receipt of cotrimoxazole preventive therapy, receipt of antiretroviral drugs, and increased age. Thus, cotrimoxazole preventive therapy may lead to fewer prescriptions for antibacterial drugs for these infants.

Exposure of Adults to Antibiotics in a Shanghai Suburban Area and Health Risk Assessment: A Biomonitoring-Based Study

An extensive exposure to antibiotics has been demonstrated in children and pregnant women by biomonitoring, but data from general adults remain limited. In the current study, we studied 822 adults aged 21-75 years in Shanghai in 2017 and analyzed 18 common antibiotics (five veterinary antibiotics (VAs), four human antibiotics (HAs), and nine human/veterinary antibiotics (H/VAs)) in spot urine by liquid chromatography coupled to high-resolution mass spectrometry. All 18 antibiotics were detected in urine with an overall detection frequency of 45.9% and the detection frequency for each ranged from 0.1% to 15.2%. HAs, VAs, H/VAs, and VAs+H/VAs were detected in 4.4%, 11.6%, 38.0, and 44.5% of urine samples, respectively. Adults with the sum of estimated daily exposure dose of all the antibiotics below 1.55 μg/kg/day accounted for 89.1% of adults tested positive. A hazard index value beyond one was seen in 7.2% of adults based on microbiological effect. Ciprofloxacin was the biggest contributor to HI and its hazard quotient value more than one was seen in 5.6% of adults. These findings indicated an extensive exposure to low-dose multiple antibiotics in adults in Shanghai and some adults were at health risk related to the disturbance of gut microbiota.

Obesity: A New Adverse Effect of Antibiotics?

Since the introduction of antibiotics, they have been used freely, with their prescription occurring almost always when they were not necessary. The other major form of contact between humans and antibiotics, now unintentionally, is with the large amount of these drugs in the environment and in our food. The relationship between antibiotic use and the development of obesity has become increasingly evident and apparent in humans, with some authors clearly establishing the relationship between the large-scale use of antibiotics in the past 70 years and the “epidemic” of obesity that has occurred in parallel, almost as an adverse epidemiological effect. In the research effort entertained herein, a correlation between the use and abuse of antibiotics and the onset of obesity was investigated.

Predictors of urinary antibiotics in children of Shanghai and health risk assessment

BACKGROUND

An extensive exposure to antibiotics has been confirmed in children, but the predictors and potential health risk remain unclear.

OBJECTIVE

To investigate the predictors of antibiotics in urine and potential health risk in children of Shanghai.

METHODS

We selected 284 school children aged 8-11 years from a central area of Shanghai, China, in 2017. Ultra-performance liquid chromatography coupled with high-resolution mass spectrometry was used to measure 20 antibiotics, including four human antibiotics (HAs), six veterinary antibiotics (VAs), 10 human/veterinary antibiotics (H/VAs), and three metabolites in first morning urine. Logistic regression model was used to examine the associations of 17 variables related to demographic and socioeconomic factors, recent antibiotic use, drinking water intake, food consumption, and anthropometric measurements with the detection frequency of HAs, VAs, or H/VAs in urine. After daily intake was estimated, health risk was assessed for VAs and H/VAs by using hazard quotient (HQ) and hazard index (HI) based on microbiological or toxicological effects.

RESULTS

The detection frequencies of 20 antibiotics and three metabolites ranged from 0 to 27.8% with an overall detection frequency being 56.0%. The detection frequency of HAs increased with age and screen time at weekend. Sex, age, family income and screen time were positively associated with the detection frequencies of VAs and H/VAs. Children reporting antibiotic use in the past three months had a higher detection frequency of HAs. Children with a higher consumption frequency of dairy products had a higher detection frequency of VAs + H/VAs, but a lower detection frequency of HAs. An increased overall detection frequency of all antibiotics was seen in children with higher consumption frequencies of aquatic products, livestock and poultry meat, or milk and dairy products. HQ >1 was only found for ciprofloxacin (5.6%) and ofloxacin (0.4%) based on microbiological effect. HI >1 was found in 6.0% of children for microbiological effect and none was found for toxicological effect.

CONCLUSIONS

Predictors for antibiotics in urine for children included sex, age, family income, screen time, clinical use, and animal-derived food consumption. There was potential health risk for children with exposure to antibiotics.

Obesity and asthma: risk, control and treatment

Asthma and obesity are currently one of the most common diseases. Observing an increase in morbidity of obesity and asthma, it can be concluded that there is a link between these diseases. But the mechanism of this relation is not well known. Due to reduced movement in patients and treatment, asthma is conducive to obesity, and obesity can exacerbate the symptoms associated with asthma. Obesity can affect bronchial hyperresponsiveness. Increasing body fat in obese people leads to systemic inflammation and elevated serum levels of many proinflammatory cytokines (e.g. leptin) and anti-inflammatory ones (e.g. adiponectin) that can have a causal relationship to bronchial asthma, but human studies are ambiguous. Obese asthmatics are characterized by a phenotype: heavier asthma, worse response to treatment and control of asthma. It has been found that in obese people, weight loss reduces the severity of asthma symptoms, so in these patients, treatment should include weight control.

Development of the Gut Microbiome in Children, and Lifetime Implications for Obesity and Cardiometabolic Disease

Emerging evidence suggests that microbiome composition and function is associated with development of obesity and metabolic disease. Microbial colonization expands rapidly following birth, and microbiome composition is particularly variable during infancy. Factors that influence the formation of the gut microbiome during infancy and childhood may have a significant impact on development of obesity and metabolic dysfunction, with life-long consequences. In this review, we examine the determinants of gut microbiome composition during infancy and childhood, and evaluate the potential impact on obesity and cardiometabolic risk.

Advances in optimizing the prescription of antibiotics in outpatient settings

The inappropriate use of antibiotics can increase the likelihood of antibiotic resistance and adverse events. In the United States, nearly a third of antibiotic prescriptions in outpatient settings are unnecessary, and the selection of antibiotics and duration of treatment are also often inappropriate. Evidence shows that antibiotic prescribing is influenced by psychosocial factors, including lack of accountability, perceived patient expectations, clinician workload, and habit. A varied and growing body of evidence, including meta-analyses and randomized controlled trials, has evaluated interventions to optimize the use of antibiotics. Interventions informed by behavioral science-such as communication skills training, audit and feedback with peer comparison, public commitment posters, and accountable justification-have been associated with improved antibiotic prescribing. In addition, delayed prescribing, active monitoring, and the use of diagnostics are guideline recommended practices that improve antibiotic use for some conditions. In 2016, the Centers for Disease Control and Prevention released the Core Elements of Outpatient Antibiotic Stewardship, which provides a framework for implementing these interventions in outpatient settings. This review summarizes the varied evidence on drivers of inappropriate prescription of antibiotics in outpatient settings and potential interventions to improve their use in such settings.

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.

Comparison of Glucose and Satiety Hormone Response to Oral Glucose vs. Two Mixed-Nutrient Meals in Rats

The obesity epidemic is driving interest in identifying strategies that enhance appetite control by altering the secretion of hormones that regulate satiety and food intake. An appropriate nutrient stimulus, such as a meal or oral nutrient solution, is needed to elicit the secretion of satiety hormones in order to evaluate the impact of dietary and other interventions. Our objective was to compare the effects of oral glucose vs. mixed nutrients on plasma concentrations of glucose and appetite-regulating hormones to determine the most appropriate oral nutrient challenge to trigger robust hormone secretion. A 120 min oral glucose tolerance test (OGTT) was compared with two meal tolerance tests (MTT) of differing formulation to evaluate glucose and satiety hormone responses. Following overnight feed deprivation, male Sprague-Dawley rats were given one of three oral gavages with equal carbohydrate content (2 g CHO/kg) in the form of: (1) Dextrose, (2) Ensure®, or (3) Mixed Meal. A fourth group was given saline as a control. Blood was collected via tail snip and analyzed for glucose, insulin, GLP-1, GIP, PYY, amylin, leptin, and ghrelin. Dextrose resulted in the highest blood glucose at T15 (P = 0.014), while the mixed meal was significantly higher than saline from T30-T120 (P < 0.05). Insulin was higher at T15 with dextrose compared to saline (P = 0.031) and Ensure® (P = 0.033). GLP-1 tAUC was significantly higher with dextrose compared to mixed meal (P = 0.04) while GIP tAUC was higher with dextrose and mixed meal compared to saline (P < 0.05). Changes in tAUC for insulin, amylin, leptin, ghrelin, and PYY did not reach significance. Based on these findings, dextrose appears to provide a robust acute glycemic and hormone response and is therefore likely an appropriate oral solution to reproducibly test the impact of various dietary, surgical, or pharmacological interventions on glucose and satiety hormone response.

Child Weight Gain Trajectories Linked To Oral Microbiota Composition

Gut and oral microbiota perturbations have been observed in obese adults and adolescents; less is known about their influence on weight gain in young children. Here we analyzed the gut and oral microbiota of 226 two-year-olds with 16S rRNA gene sequencing. Weight and length were measured at seven time points and used to identify children with rapid infant weight gain (a strong risk factor for childhood obesity), and to derive growth curves with innovative Functional Data Analysis (FDA) techniques. We showed that growth curves were associated negatively with diversity, and positively with the Firmicutes-to-Bacteroidetes ratio, of the oral microbiota. We also demonstrated an association between the gut microbiota and child growth, even after controlling for the effect of diet on the microbiota. Lastly, we identified several bacterial genera that were associated with child growth patterns. These results suggest that by the age of two, the oral microbiota of children with rapid infant weight gain may have already begun to establish patterns often seen in obese adults. They also suggest that the gut microbiota at age two, while strongly influenced by diet, does not harbor obesity signatures many researchers identified in later life stages.

Antibiotic exposure in early life and childhood overweight and obesity: A systematic review and meta-analysis

We conducted a systematic review and meta-analysis of observational studies investigating the association between antibiotic exposure in infancy and risk of childhood overweight and obesity. Thirteen studies, including a total of 527 504 children, were included in the systematic review and 8 were included in meta-analyses. Exposure to antibiotics in infancy was associated with an increased odds ratio (OR) of childhood overweight and obesity (OR 1.11, 95% confidence interval [CI] 1.02-1.20). Whereas exposure to 1 treatment only and exposure between 6 and 24 months were not associated with increased risk of childhood overweight and obesity, exposure to >1 treatment was associated with an OR of 1.24 (95% CI 1.09-1.43) and exposure within the first 6 months of life was associated with an OR of 1.20 (95% CI 1.04-1.37). In conclusion, antibiotic exposure in infancy was associated with a slightly increased risk of childhood overweight and obesity, mainly if children were exposed to repeated treatments or treatment within the first 6 months of life. It is unclear whether this association is mediated via direct effects of antibiotics on the gut microbiota.

Obesity, underweight and BMI distribution characteristics of children by gross national income and income inequality: results from an international survey

BACKGROUND

Economic wealth and income inequality may impact on childhood BMI distribution by affecting overconsumption of food and sedentary forms of transportation and entertainment across the whole or some of the population.

OBJECTIVES

To determine whether BMI distribution of children differs by gross national income (GNI) per capita and Gini index derived from World Bank data.

METHODS

Secondary analysis of largely self-reported height and weight data from a multi-country, cross-sectional study (ISAAC), of 77,963 children aged 6-7 (from 19 countries) and 205,388 adolescents aged 13-14 (from 36 countries), were used to examine underweight vs obesity prevalence and BMI distribution skewness, median and dispersion.

RESULTS

Children and adolescents from 'lower' GNI countries had higher prevalence of underweight than those from 'higher' GNI countries (6% vs 3%, p = 0.03; 2% vs 1%, p = 0.05 respectively), but the prevalence of obesity was not different (2% vs 5%, p = 0.29; 2% vs 2%, p = 0.66). BMI distribution of participants from 'higher' GNI countries had higher median, without significant difference in skewness or dispersion compared to 'lower' GNI countries (higher medians +1.1 kg/m2 for 6-7 year olds, and + 0.7 kg/m2, +1.2 kg/m2 for 13-14 year old girls and boys respectively). Gini index was not associated with underweight or obesity prevalence in either children or adolescents, nor with any BMI distribution characteristics with one exception. Adolescent girls from higher income inequality countries had a greater median BMI (+0.7 kg/m2) and a less skewed BMI distribution.

CONCLUSIONS

It appears that the obesogenic impact of economic prosperity affects all children similarly. Income inequality may have a gender specific effect affecting BMI distribution in adolescent girls.

Factors associated with body mass index in children and adolescents: An international cross-sectional study

BACKGROUND

The increasing prevalence of overweight and obesity in childhood has implications for their future health. There are many potential contributors to overweight and obesity in childhood. The aim was to investigate the association between postulated risk factors and body mass index (BMI) in children and adolescents.

METHODS

Secondary analysis of data from a multi-centre, multi-country, cross-sectional study (ISAAC Phase Three). Parents/guardians of children aged 6-7 years completed a questionnaire about their child's current height and weight, and the postulated risk factors. Adolescents aged 13-14 years reported their own height and weight and answered questions about the postulated risk factors. A general linear mixed model was used to determine the association between BMI and the postulated risk factors. Imputation was used if there were missing responses for 3 or fewer explanatory variables.

RESULTS

65,721 children (27 centres, 15 countries) and 189,282 adolescents (70 centres, 35 countries) were included in the final analyses. Many statistically significant associations were identified, although for most variables the effect sizes were small. In children birth weight (for each kg increase in birth weight the BMI increased by +0.43 kg/m2, p<0.001), television viewing (5+ hours/day +0.33 kg/m2 vs. <1 hour/day, p<0.001), fast food (≥3 times/week +0.16 kg/m2 vs. never, p<0.001) vigorous physical activity (3+ hours/week 0.071 kg/m2 vs. never, p = 0.023) and maternal smoking in the first year of life (+0.13 kg/m2, p<0.001) were associated with a higher BMI in the adjusted model. Nut consumption (≥3 times/week -0.11 kg/m2 vs. never, p = 0.002) was associated with a lower BMI. Early life exposures (antibiotics, paracetamol and breast feeding) were also associated with BMI. For adolescents statistically significant associations with BMI and were seen with maternal smoking (+0.25 kg/m2, p<0.001), television viewing (5+ hours/day +0.23 kg/m2 vs. <1 hour/day, p<0.001), fast food (≥3 times/week -0.19 kg/m2 vs. never, p<0.001), vigorous physical activity (3+ hours/week 0.047 kg/m2 vs. never, p<0.001) and nuts (≥3 times/week -0.22 kg/m2 vs. never, p<0.001).

CONCLUSIONS

Although several early life exposures were associated with small differences in BMI, most effect sizes were small. Larger effect sizes were seen with current maternal smoking, television viewing (both with higher BMI) and frequent nut consumption (lower BMI) in both children and adolescents, suggesting that current behaviours are more important than early exposures. Although many variables may influence BMI in childhood, the putative factors studied are not of sufficient magnitude to support major public health interventions.

Systemic use of antibiotics and risk of diabetes in adults: A nested case-control study of Alberta's Tomorrow Project

AIMS

Previous observational studies using administrative health records have suggested an increased risk of diabetes with use of antibiotics. However, unmeasured confounding factors may explain these results. This study characterized the association between systemic use of antibiotics and risk of diabetes in a cohort of adults in Canada, accounting for both clinical and self-reported disease risk factors.

MATERIALS AND METHODS

In this nested case-control study, we used data from Alberta's Tomorrow Project (ATP), a longitudinal cohort study in Canada, and the linked administrative health records (2000-2015). Incident cases of diabetes were matched with up to 8 age and sex-matched controls per case. Conditional logistic regression was used to examine the association between antibiotic exposures and incident diabetes after sequentially adjusting for important clinical and lifestyle factors.

RESULTS

This study included 1676 cases of diabetes and 13 401 controls. Although 17.9% of cases received more than 5 courses of antibiotics, compared to 13.8% of controls (P < .0001), the association between antibiotic use and risk of diabetes was progressively reduced as important clinical and lifestyle factors were accounted for. In fully adjusted models, compared to participants with 0 to 1 courses of antibiotics, participants receiving more antibiotics had no increased risk of diabetes [Odds Ratio, 0.97 (0.83-1.13) for 2 to 4 courses and 0.98 (0.82-1.18) for ≥5 courses].

CONCLUSIONS

After adjustment for clinical and difficult-to-capture lifestyle data, we found no association between systemic use of antibiotics and risk of diabetes. Our results suggest that those positive associations observed in previous studies using only administrative records might have been confounded.

Antibiotics, gut microbiome and obesity

Antibiotics have been hailed by many as "miracle drugs" that have been effectively treating infectious diseases for over a century, leading to a marked reduction in morbidity and mortality. However, with the increasing use of antibiotics, we are now faced not only with the increasing threat of antibiotic resistance, but also with a rising concern about potential long-term effects of antibiotics on human health, including the development of obesity. The obesity pandemic continues to increase, a problem that affects both adults and children alike. Disruptions to the gut microbiome have been linked to a multitude of adverse conditions, including obesity, type 2 diabetes, inflammatory bowel diseases, anxiety, autism, allergies, and autoimmune diseases. This review focuses on the association between antibiotics and obesity, and the role of the gut microbiome. There is strong evidence supporting the role of antibiotics in the development of obesity in well-controlled animal models. However, evidence for this link in humans is still inconclusive, and we need further well-designed clinical trials to clarify this association.

Bifidobacteria and the infant gut: an example of co-evolution and natural selection

Throughout the human life, the gut microbiota interacts with us in a number of different ways, thereby influencing our health status. The acquisition of such an interactive gut microbiota commences at birth. Medical and environmental factors including diet, antibiotic exposure and mode of delivery are major factors that shape the composition of the microbial communities in the infant gut. Among the most abundant members of the infant microbiota are species belonging to the Bifidobacterium genus, which are believed to confer beneficial effects upon their host. Bifidobacteria may be acquired directly from the mother by vertical transmission and their persistence in the infant gut is associated with their saccharolytic activity toward glycans that are abundant in the infant gut. Here, we discuss the establishment of the infant gut microbiota and the contribution of bifidobacteria to this early life microbial consortium.

Anti-microbial stewardship: antibiotic use in well-appearing term neonates born to mothers with chorioamnionitis

OBJECTIVE

To determine if implementation of a protocol based on a neonatal early-onset sepsis (EOS) calculator developed by Kaiser Permanente would safely reduce antibiotic use in well-appearing term infants born to mothers with chorioamnionitis in the unique setting of an Observation Nursery.

STUDY DESIGN

Data obtained from a retrospective chart review of well-appearing term infants born between 2009 and 2016 were entered into the EOS calculator to obtain management recommendations.

RESULTS

Three hundred and sixty-two infants met the study criteria. Management according to the EOS calculator would reduce antibiotic use from 99% to 2.5% (P<0.0001) of patients. Average length of therapy would also decrease from 2.08 to 0.05 days (P<0.0001). One infant, who remained asymptomatic, had Enterococcus bacteremia and received a 7-day course of broad-spectrum antibiotics.

CONCLUSIONS

Culture-positive sepsis in asymptomatic neonates born to mothers with chorioamnionitis is rare. Management according to the EOS calculator would markedly reduce the potential complications of antibiotic use. These data should initiate re-examination of existing protocols for management of this cohort of patients.

Veterinary antibiotics in food, drinking water, and the urine of preschool children in Hong Kong

Due to the harmful effects of veterinary antibiotics (VAs) residues in food on children's health, urine samples from 31 preschool and primary school children were analyzed for 13 common VAs. Samples of raw and cooked pork, chicken, fish, milk and drinking water from the children's living areas were also analyzed for residual VAs. Urinalysis revealed one to four target antibiotics in 77.4% of the sample group, with concentrations as high as 0.36ng/mL. Norfloxacin and penicillin had the highest detection rates (48.4% and 35.5%, respectively), with median concentrations of 0.037 and 0.13ng/mL, respectively. The VA burden of children in HK was lower than that in Shanghai. Enrofloxacin, penicillin, and erythromycin were the most detected VAs in raw and cooked food. Only oxytetracycline was detected in terminal tap water, and none were detected in milk. Tetracycline and doxycycline hyclate were detected in organic eggs (up to 7.1ng/g) and regular eggs (up to 6.6ng/g), which were common in children's diets. Traditional Chinese cooking processes did not completely eliminate VAs, and the concentrations of some VAs increased, especially after frying and roasting. The estimated daily intake (EDI) results show that the contribution of dietary intake and that based on the urine concentrations of VAs were far below the acceptable daily intake (ADI). The EDIs from urine were significantly lower than those based on cooked foods. The highest level of achievement percentage (LAP) based on dietary consumption and urine concentrations were 39.7% and 1.79%, respectively, and thus current levels of exposure to VAs would not seem to pose a risk to children's health. However, harmful effects of residual VAs during developmental periods may occur with exposure to much lower doses than those considered harmful to adults, and further investigation of these emerging pollutants is urgently encouraged.

Early Antibiotic Exposure in Low-resource Settings Is Associated With Increased Weight in the First Two Years of Life

OBJECTIVES

The potential growth-promoting effects of antibiotics are not well understood among undernourished children in environments with high pathogen exposure. We aimed to assess whether early antibiotic exposure duration and class were associated with growth to 2 years of age across 8 low-resource sites in the MAL-ED birth cohort study.

METHODS

We followed 1954 children twice per week from birth to 2 years to record maternally reported antibiotic exposures and measure anthropometry monthly. We estimated the associations between antibiotic exposure before 6 months of age and weight-for-age and length-for-age (LAZ) z scores to 2 years. We assessed the impact of class-specific exposures and duration, and compared these results to effects of antibiotic exposures after 6 months of age.

RESULTS

Antibiotic use before 6 months of age was associated with increased weight from 6 months to 2 years, whereas associations with length were less consistent across sites and antibiotic classes. Compared to unexposed children, 2 or more courses of metronidazole, macrolides, and cephalosporins were associated with adjusted increases in weight-for-age of 0.24 (95% confidence interval (CI): 0.04, 0.43), 0.23 (95% CI: 0.05, 0.42), and 0.19 (95% CI: 0.04, 0.35) from 6 months to 2 years, respectively.

CONCLUSIONS

Antibiotic use in low-resource settings was most associated with the ponderal growth of children who had multiple exposures to antibiotics with broad spectrum and anaerobic activity in early infancy. Opportunities for rational and targeted antibiotic therapy in low resource settings may also promote short-term weight gain in children, although longer-term physical growth and metabolic impacts are unknown.

Obesity and Asthma: A Missing Link

Obesity and asthma are two chronic conditions that affect millions of people. Genetic and lifestyle factors such as diet, physical activity, and early exposure to micro-organisms are important factors that may contribute to the escalating prevalence of both conditions. The prevalence of asthma is higher in obese individuals. Recently, two major phenotypes of asthma with obesity have been described: one phenotype of early-onset asthma that is aggravated by obesity, and a second phenotype of later-onset asthma that predominantly affects women. Systemic inflammation and mechanical effect, both due to the expansion of the adipose tissue, have been proposed as the main reasons for the association between obesity and asthma. However, the mechanisms involved are not yet fully understood. Moreover, it has also been suggested that insulin resistance syndrome can have a role in the association between these conditions. The intestinal microbiota is an important factor in the development of the immune system, and can be considered a link between obesity and asthma. In the obese state, higher lipopolysaccharide (LPS) serum levels as a consequence of a microbiota dysbiosis have been found. In addition, changes in microbiota composition result in a modification of carbohydrate fermentation capacity, therefore modifying short chain fatty acid (SCFA) levels. The main objective of this review is to summarize the principal findings that link obesity and asthma.

Gut microbiota composition strongly correlates to peripheral insulin sensitivity in obese men but not in women

Gut microbiota composition may play an important role in the development of obesity-related comorbidities. However, only few studies have investigated gender-differences in microbiota composition and gender-specific associations between microbiota or microbial products and insulin sensitivity. Insulin sensitivity (hyperinsulinemic-euglycemic clamp), body composition (dual energy X-ray absorptiometry), substrate oxidation (indirect calorimetry), systemic inflammatory markers and microbiota composition (PCR) were determined in male (n=15) and female (n=14) overweight and obese subjects. Bacteroidetes/Firmicutes-ratio was higher in men than in women (P=0.001). Bacteroidetes/Firmicutes-ratio was inversely related to peripheral insulin sensitivity only in men (men: P=0.003, women: P=0.882). This association between Bacteroidetes/Firmicutes-ratio and peripheral insulin sensitivity did not change after adjustment for dietary fibre and saturated fat intake, body composition, fat oxidation and markers of inflammation. Bacteroidetes/Firmicutes-ratio was not associated with hepatic insulin sensitivity. Men and women differ in microbiota composition and its impact on insulin sensitivity, implying that women might be less sensitive to gut microbiota-induced metabolic aberrations than men. This trial was registered at clinicaltrials.gov as NCT02381145.

Food additives, contaminants and other minor components: effects on human gut microbiota-a review

Gut bacteria play an important role in several metabolic processes and human diseases, such as obesity and accompanying co-morbidities, such as fatty liver disease, insulin resistance/diabetes, and cardiovascular events. Among other factors, dietary patterns, probiotics, prebiotics, synbiotics, antibiotics, and non-dietary factors, such as stress, age, exercise, and climatic conditions, can dramatically impact the human gut microbiota equilibrium and diversity. However, the effect of minor food constituents, including food additives and trace contaminants, on human gut microbiota has received less attention. Consequently, the present review aimed to provide an objective perspective of the current knowledge regarding the impacts of minor food constituents on human gut microbiota and consequently, on human health.

Early life antibiotic exposure affects pancreatic islet development and metabolic regulation

Childhood antibiotic exposure has been recently linked with increased risk of metabolic disease later in life. A better understanding of this association would potentially provide strategies to reduce the childhood chronic disease epidemic. Therefore, we explored the underlying mechanisms using a swine model that better mimics human infants than rodents, and demonstrated that early life antibiotic exposure affects glucose metabolism 5 weeks after antibiotic withdrawal, which was associated with changes in pancreatic development. Antibiotics exerted a transient impact on postnatal gut microbiota colonization and microbial metabolite production, yet changes in the expression of key genes involved in short-chain fatty acid signaling and pancreatic development were detected in later life. These findings suggest a programming effect of early life antibiotic exposure that merits further investigation.

Associations of prenatal and childhood antibiotic use with child body mass index at age 3 years

OBJECTIVE

Early-life antibiotic exposure, whether through prenatal or childhood antibiotic use, may contribute to increased child body mass. Associations of prenatal and childhood antibiotic use with body mass index z-score (BMIz) were evaluated at age 3 years.

METHODS

Electronic health records were utilized from 8,793 mothers and singleton children delivered at Geisinger Clinic in Pennsylvania between 2006 and 2012. Antibiotic orders were ascertained for mothers during pregnancy and for children through their age-3 BMI measurement. Linear mixed-effects regression models evaluated associations of prenatal and childhood antibiotic use with child BMIz.

RESULTS

Prenatal antibiotic orders were not associated with child BMIz. Children in the three largest categories of lifetime antibiotic orders had higher BMIz compared with children with no orders; associations persisted when controlling for prenatal antibiotics (β [95% confidence interval]) (4-5 child orders: 0.090 [0.011 to 0.170]; 6 to 8: 0.113 [0.029 to 0.197]; ≥9: 0.175 [0.088 to 0.263]; trend P value <0.001). Two or more first-year orders were also associated with BMIz (1: 0.021 [-0.038 to 0.081]; 2: 0.088 [0.017 to 0.160]; ≥3: 0.104 [0.038 to 0.170]; trend P value < 0.001).

CONCLUSIONS

Associations of early-life and lifetime childhood antibiotic use with increased child BMI highlight antibiotic exposure as a modifiable factor for reducing population-level excess weight.

Antibiotic Exposure in Early Life Increases Risk of Childhood Obesity: A Systematic Review and Meta-Analysis

A number of studies have previously assessed the impact of antibiotic exposure in early life on the risk of childhood obesity, but no systematic assessment is currently available. A systematic review and meta-analysis was performed to comprehensively and quantitatively elucidate the risk of childhood obesity caused by antibiotic exposure in early life. Literature search was performed in PubMed, Embase, and Web of Science. Random-effect meta-analysis was used to pool the statistical estimates. Fifteen cohort studies involving 445,880 participants were finally included, and all those studies were performed in developed countries. Antibiotic exposure in early life significantly increased risk of childhood overweight [relative risk (RR) = 1.23, 95% confidence interval (CI) 1.13-1.35, P < 0.001] and childhood obesity (RR = 1.21, 95% CI 1.13-1.30, P < 0.001). Antibiotic exposure in early life also significantly increased the z-score of childhood body mass index (mean difference: 0.07, 95% CI 0.05-0.09, P < 0.00001). Importantly, there was an obvious dose-response relationship between antibiotic exposure in early life and childhood adiposity, with a 7% increment in the risk of overweight (RR = 1.07, 95% CI 1.01-1.15, P = 0.03) and a 6% increment in the risk of obesity (RR = 1.06, 95% CI 1.02-1.09, P < 0.001) for each additional course of antibiotic exposure. In conclusion, antibiotic exposure in early life significantly increases risk of childhood obesity. Moreover, current analyses are mainly taken from developed countries, and therefore the impact of antibiotic exposure on risk of childhood obesity in vulnerable populations or developing countries still needs to be evaluated in future studies.

Management of Helicobacter pylori infection-the Maastricht V/Florence Consensus Report

Important progress has been made in the management of Helicobacter pylori infection and in this fifth edition of the Maastricht Consensus Report, key aspects related to the clinical role of H. pylori were re-evaluated in 2015. In the Maastricht V/Florence Consensus Conference, 43 experts from 24 countries examined new data related to H. pylori in five subdivided workshops: (1) Indications/Associations, (2) Diagnosis, (3) Treatment, (4) Prevention/Public Health, (5) H. pylori and the Gastric Microbiota. The results of the individual workshops were presented to a final consensus voting that included all participants. Recommendations are provided on the basis of the best available evidence and relevance to the management of H. pylori infection in the various clinical scenarios.

Antibiotics in the first year of life and subsequent neurocognitive outcomes

AIM

There may be a link between disruption to the gut microbiota in early life and later neurocognitive outcomes. We hypothesised that antibiotic use in early life is associated with a detrimental effect on later neurocognitive outcomes.

METHODS

Eight hundred and seventy-one European mothers and their children enrolled in the Auckland Birthweight Collaborative Study at birth. Information on antibiotic use during the first year of life and between 12 months and three-and-a-half years of age was gathered via maternal interview. Intelligence test scores and measures of behavioural difficulties were obtained when children were three-and-a-half years, seven years and 11 years of age.

RESULTS

Antibiotic use in the first year of life was reported in 70% of the 526 children with antibiotic data assessed at age three-and-a-half years. Those who had received antibiotics had more behavioural difficulties and more symptoms of depression at follow-up. Results were consistent across all standardised psychologist administered tests, as well as parent rated, teacher rated and self-report measures.

CONCLUSION

This study demonstrates an association between antibiotic use in the first year of life and subsequent neurocognitive outcomes in childhood. If confirmed by further research, these findings could have implications for the use of antibiotics for minor illnesses in infancy.

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

BACKGROUND

Data from previous studies have suggested a possible association between antibiotic use in infancy and risk of childhood obesity, with implications for health-care delivery and obesity prevention strategies. However, whether the observed association was due to antibiotic use or underlying infection, or both, is unclear. We aimed to disentangle the effect of antibiotic use in infancy from that of underlying infection on the risk of childhood obesity.

METHODS

In this longitudinal birth cohort study, we included infants in the Kaiser Permanente Northern California population born between Jan 1, 1997, and March 31, 2013. We used electronic medical records to ascertain data for antibiotic use, infection diagnosis, and anthropometric measurements (and thus BMI and obesity status) from birth up to age 18 years. We used standard mixed-effects logistic regression for repeated measurements to analyse multiple BMI measurements per child (median five measurements) and to obtain odds ratios (ORs) and 95% CIs for obesity risk. We also did a substudy in 547 same-sex twin pairs with discordant exposure status to substantiate our findings.

FINDINGS

260 556 individuals were included in our analysis. After controlling for maternal age, race or ethnic origin, pre-pregnancy BMI, preterm delivery, low birthweight, maternal antibiotic use, and infection during pregnancy, infection without antibiotic use in infancy was associated with an increased risk of childhood obesity compared with controls without infection (OR 1·25, 95% CI 1·20-1·29). A clear dose-response relation was seen between infection episodes and risk of childhood obesity (p_trend <0·0001). By contrast, compared with infants with untreated infection, antibiotic use during infancy was not associated with risk of childhood obesity (1·01, 0·98-1·04). Neither broad-spectrum nor narrow-spectrum antibiotics were associated with risk of childhood obesity. These findings were supported by the results of the twin set analysis.

INTERPRETATION

Infection, but not antibiotic use, during infancy is associated with risk of childhood obesity. This finding will need to be replicated in future studies. Although our results do not rule out a potential effect of antibiotics on microbiome composition and the use of antibiotics should always be judicious, they suggest that treatment of common infections with antibiotics in infancy is unlikely to be a main contributor to childhood obesity.

FUNDING

Kaiser Permanente Center for Effectiveness & Safety Research.

Early Life Antibiotic Exposure and Weight Development in Children

OBJECTIVE

To examine the timing, frequency, and type of antibiotic exposure during the first 10 years of life in association with (over)weight across this period in a cohort of 979 children.

STUDY DESIGN

Within the Child, Parents and Health: Lifestyle and Genetic Constitution Birth Cohort Study, antibiotic exposure record was obtained from general practitioners. Anthropometric outcomes (age- and sex-standardized body mass index, weight and height z-scores, and overweight) were measured repeatedly at 7 time points during the first 10 years of life. Generalized estimating equations method was used for statistical analysis.

RESULTS

After adjusting for confounding factors, children exposed to one course of antibiotics compared with none in the first 6 months of life had increased weight- (adjusted generalized estimating equations estimates [adjβ] 0.24; 95% CI 0.03-0.44) and height (adjβ 0.23; 95% CI 0.0002-0.46) z-scores; exposure to ≥2 courses during the second year of life was associated with both increased weight (adjβ 0.34; 95% CI 0.07-0.60), and height z-scores (adjβ 0.29; 95% CI -0.003 to 0.59). Exposure later in life was not associated with anthropometric outcomes. Associations with weight z-scores were mainly driven by exposure to broad- (≥2 courses: adjβ 0.11; 95% CI 0.003-0.22) and narrow-spectrum β-lactams (1 course: adjβ 0.18; 95% CI 0.005-0.35) during the follow-up period. Specific antibiotic used was not associated with body mass index z-scores and overweight.

CONCLUSIONS

Repeated exposure to antibiotics early in life, especially β-lactam agents, is associated with increased weight and height. If causality of obesity can be established in future studies, this further highlights the need for restrictive antibiotic use and avoidance of prescriptions when there is minimal clinical benefit.

Administration of Antibiotics to Children Before Age 2 Years Increases Risk for Childhood Obesity

BACKGROUND & AIMS

Childhood obesity is increasing and is associated with adult obesity. Antibiotics have been used to promote weight gain in livestock for several decades. Antibiotics are commonly prescribed for children, but it is not clear how exposure to antibiotics early in life affects risk for obesity. We performed a population-based cohort study to assess the association between antibiotic exposure before age 2 years and obesity at age 4 years.

METHODS

We performed a retrospective cohort study of 21,714 children in The Health Improvement Network-a population-representative dataset of >10 million individuals derived from electronic medical records from 1995 through 2013 in the United Kingdom. Eligible subjects were registered within 3 months of birth with complete follow-up and height and weight were recorded within 12 months of their 4th birthday. Antibiotic exposure was assessed before age 2 years, and classified based on anti-anaerobic activity. The primary outcome was obesity at age 4 years. We performed logistic regression analyses, adjusting for maternal and sibling obesity, maternal diabetes, mode of delivery, socioeconomic status, year and country of birth, and urban dwelling.

RESULTS

In the cohort, 1306 of the children (6.4%) were obese at 4 years of age. Antibiotic exposure was associated with an increased risk of obesity at 4 years (odds ratio [OR] = 1.21; 95% confidence interval [CI]: 1.07-1.38). ORs increased with repeated exposures: for 1-2 prescriptions, OR = 1.07 (95% CI, 0.91-1.23); for 3-5 prescriptions, OR = 1.41 (95% CI, 1.20-1.65); and for 6 or more prescriptions, OR = 1.47 (95% CI, 1.19-1.82). Antifungal agents were not associated with obesity (OR = 0.81; 95% CI, 0.59-1.11).

CONCLUSIONS

Administration of 3 or more courses of antibiotics before children reach an age of 2 years is associated with an increased risk of early childhood obesity.

The Long-Term Public Health Benefits of Breastfeeding

Breastfeeding has many health benefits, both in the short term and the longer term, to infants and their mothers. There is an increasing number of studies that report on associations between breastfeeding and long-term protection against chronic disease. Recent research evidence is reviewed in this study, building on previous authoritative reviews. The recent World Health Organization reviews of the short- and long-term benefits of breastfeeding concluded that there was strong evidence for many public health benefits of breastfeeding. Cognitive development is improved by breastfeeding, and infants who are breastfed and mothers who breastfeed have lower rates of obesity. Other chronic diseases that are reduced by breastfeeding include diabetes (both type 1 and type 2), obesity, hypertension, cardiovascular disease, hyperlipidemia, and some types of cancer.

Effect of antibiotics on gut microbiota, glucose metabolism and body weight regulation: a review of the literature

Gut bacteria are involved in a number of host metabolic processes and have been implicated in the development of obesity and type 2 diabetes in humans. The use of antibiotics changes the composition of the gut microbiota and there is accumulating evidence from observational studies for an association between exposure to antibiotics and development of obesity and type 2 diabetes. In the present paper, we review human studies examining the effects of antibiotics on body weight regulation and glucose metabolism and discuss whether the observed findings may relate to alterations in the composition and function of the gut microbiota.

Antibiotics detected in urines and adipogenesis in school children

BACKGROUND

Although antibiotic use during early life has been demonstrated to be related to the altered adipogenesis in later life, limited data are available for the effect of antibiotic exposure in school children on adiposity from various sources, including from the use or contaminated food or drinking water.

OBJECTIVE

To explore the association between the internal exposure of antibiotics from various sources and adipogenesis in school children using the biomonitoring of urinary antibiotics.

METHODS

After 586 school children aged 8-11years were selected from Shanghai in 2013, total urinary concentrations (free and conjugated) of 21 common antibiotics from six categories (macrolides, β-lactams, tetracyclines, fluoroquinolones, sulfonamides, and phenicols), including five human antibiotics (HAs), two antibiotics preferred as HA, four veterinary antibiotics (VAs), and ten antibiotics preferred as VA, were measured by ultra-performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry. Creatinine-corrected urinary concentrations of antibiotics were used to assess their exposure. Overweight or obesity was determined by the body mass index or waist circumference-based criteria deriving from national data.

RESULTS

All 21 antibiotics were found in urines with the overall detection frequency of 79.6%. The multinomial logistic regression analyses showed the significant associations of overweight and obesity with the exposure to VAs and antibiotics preferred as VA, but not with HAs or antibiotics preferred as HA. After adjusted for a number of obesity-relevant variables, the odds ratios (95% confidence interval) of BMI-based obesity risk of tertiles 2 and 3 of urinary concentrations relative to tertile 1 were respectively 2.54 (1.27, 5.07) and 2.92 (1.45, 5.87) for florfenicol, 0.57 (0.12, 2.63) and 3.63 (1.41, 9.32) for trimethoprim, and 3.00 (1.56, 5.76) and 1.99 (0.99, 4.01) for sum of veterinary antibiotics. Similar results were found when the outcome used WC-based obesity risk. The associations were sex related and mainly observed in boys.

CONCLUSIONS

Some types of antibiotic exposure, which were mainly from food or drinking water, were associated with an increased risk of obesity in school children. Due to the cross-sectional design, more longitudinal and experimental studies are warranted to further test these findings.

Posttraumatic Stress Disorder: Does the Gut Microbiome Hold the Key?

Gut bacteria strongly influence our metabolic, endocrine, immune, and both peripheral and central nervous systems. Microbiota do this directly and indirectly through their components, shed and secreted, ranging from fermented and digested dietary and host products to functionally active neurotransmitters including serotonin, dopamine, and γ-aminobutyric acid. Depression has been associated with enhanced levels of proinflammatory biomarkers and abnormal responses to stress. Posttraumatic stress disorder (PTSD) appears to be marked in addition by low cortisol responses, and these factors seem to predict and predispose individuals to develop PTSD after a traumatic event. Dysregulation of the immune system and of the hypothalamic-pituitary-adrenal axis observed in PTSD may reflect prior trauma exposure, especially early in life. Early life, including the prenatal period, is a critical time in rodents, and may well be for humans, for the functional and structural development of the immune and nervous systems. These, in turn, are likely shaped and programmed by gut and possibly other bacteria. Recent experimental and clinical data converge on the hypothesis that imbalanced gut microbiota in early life may have long-lasting immune and other physiologic effects that make individuals more susceptible to develop PTSD after a traumatic event and contribute to the disorder. This suggests that it may be possible to target abnormalities in these systems by manipulation of certain gut bacterial communities directly through supplementation or indirectly by dietary and other novel approaches.

Adverse consequences of neonatal antibiotic exposure

PURPOSE OF REVIEW

Antibiotics have not only saved lives and improved outcomes, but they also influence the evolving microbiome. This review summarizes reports on neonatal infections and variation in antibiotic utilization, discusses the emergence of resistant organisms, and presents data from human neonates and animal models demonstrating the impact of antibiotics on the microbiome, and how microbiome alterations impact health. The importance of antibiotic stewardship is also discussed.

RECENT FINDINGS

Infections increase neonatal morbidity and mortality. Furthermore, the clinical presentation of infections can be subtle, prompting clinicians to empirically start antibiotics when infection is a possibility. Antibiotic-resistant infections are a growing problem. Cohort studies have identified extensive center variations in antibiotic usage and associations between antibiotic exposures and outcomes. Studies of antibiotic-induced microbiome alterations and downstream effects on the developing immune system have increased our understanding of the mechanisms underlying the associations between antibiotics and adverse outcomes. The emergence of resistant microorganisms and recent evidence linking antibiotic practice variations with health outcomes has led to the initiation of antibiotic stewardship programs.

SUMMARY

The review encourages practitioners to assess local antibiotic use with regard to local microbiology, and to adopt steps to reduce infections and use antibiotics wisely.

Effect of long-term antibiotic use on weight in adolescents with acne

OBJECTIVES

Antibiotics increase weight in farm animals and may cause weight gain in humans. We used electronic health records from a large primary care organization to determine the effect of antibiotics on weight and BMI in healthy adolescents with acne.

METHODS

We performed a retrospective cohort study of adolescents with acne prescribed ≥4 weeks of oral antibiotics with weight measurements within 18 months pre-antibiotics and 12 months post-antibiotics. We compared within-individual changes in weight-for-age Z-scores (WAZs) and BMI-for-age Z-scores (BMIZs). We used: (i) paired t-tests to analyse changes between the last pre-antibiotics versus the first post-antibiotic measurements; (ii) piecewise-constant-mixed models to capture changes between mean measurements pre- versus post-antibiotics; (iii) piecewise-linear-mixed models to capture changes in trajectory slopes pre- versus post-antibiotics; and (iv) χ(2) tests to compare proportions of adolescents with ≥0.2 Z-scores WAZ or BMIZ increase or decrease.

RESULTS

Our cohort included 1012 adolescents with WAZs; 542 also had BMIZs. WAZs decreased post-antibiotics in all analyses [change between last WAZ pre-antibiotics versus first WAZ post-antibiotics = -0.041 Z-scores (P < 0.001); change between mean WAZ pre- versus post-antibiotics = -0.050 Z-scores (P < 0.001); change in WAZ trajectory slopes pre- versus post-antibiotics = -0.025 Z-scores/6 months (P = 0.002)]. More adolescents had a WAZ decrease post-antibiotics ≥0.2 Z-scores than an increase (26% versus 18%; P < 0.001). Trends were similar, though not statistically significant, for BMIZ changes.

CONCLUSIONS

Contrary to original expectations, long-term antibiotic use in healthy adolescents with acne was not associated with weight gain. This finding, which was consistent across all analyses, does not support a weight-promoting effect of antibiotics in adolescents.

Role of Gut Microbiota in the Aetiology of Obesity: Proposed Mechanisms and Review of the Literature

The aetiology of obesity has been attributed to several factors (environmental, dietary, lifestyle, host, and genetic factors); however none of these fully explain the increase in the prevalence of obesity worldwide. Gut microbiota located at the interface of host and environment in the gut are a new area of research being explored to explain the excess accumulation of energy in obese individuals and may be a potential target for therapeutic manipulation to reduce host energy storage. Several mechanisms have been suggested to explain the role of gut microbiota in the aetiology of obesity such as short chain fatty acid production, stimulation of hormones, chronic low-grade inflammation, lipoprotein and bile acid metabolism, and increased endocannabinoid receptor system tone. However, evidence from animal and human studies clearly indicates controversies in determining the cause or effect relationship between the gut microbiota and obesity. Metagenomics based studies indicate that functionality rather than the composition of gut microbiota may be important. Further mechanistic studies controlling for environmental and epigenetic factors are therefore required to help unravel obesity pathogenesis.