Relation Between Infant Microbiota and Autism?: Results from a National Cohort Sibling Design Study

Antibiotic use and risk of autism spectrum disorder and attention-deficit/hyperactivity disorder: a population-based cohort study

BACKGROUND

The gut microbiota is believed to influence neurodevelopment through the gut-brain axis, but prior studies have shown inconsistent results regarding early childhood antibiotic exposure and subsequent risk of autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD). The purpose of this study was to evaluate the hypothesis that exposure to antibacterial agents in the first 2 years of life increases the risk of ASD and/or ADHD.

METHODS

This was a retrospective cohort study using 2003-2019 data from the National Health Insurance Research Database in Taiwan. Livebirths born between 2004 and 2016 were identified and separated into singleton, full sibling, and exposure-discordant sibling pair cohorts. The exposure group included children who filled at least one prescription for antibacterial agents between 0 and 2 years old in outpatient settings. The outcome, ASD and/or ADHD, was defined by at least one inpatient or outpatient diagnosis. The maximum follow-up age was 15 years in this study. Potential neonatal, maternal and paternal confounders were adjusted for. Cox proportional hazards models were used to estimate the relative event risk.

RESULTS

The final sample contained 946,581 children in the singleton cohort, 1,142,693 children in the full sibling cohort, and 352,612 children in the exposure-discordant sibling pair cohort. Antibiotic exposure marginally increased the risk of ASD and/or ADHD in the singleton cohort (adjusted hazard ratio [aHR]: 1.06, 95% confidence interval [CI]: 1.04-1.07) and in the full sibling cohort (aHR: 1.03, 95% CI: 1.01-1.04). A slight decrease in the risk of ASD and/or ADHD was observed in the exposure-discordant sibling pair cohort (aHR: 0.92, 95% CI: 0.90-0.94).

CONCLUSIONS

The results suggest that early life antibiotic exposure has minimal impact on the risk of ASD and/or ADHD. Given that the estimated effects are marginal and close to null, concerns about ASD and/or ADHD risk increase should not postpone or deter timely and reasonable antibiotic use.

Microbiota-brain axis: Exploring the role of gut microbiota in psychiatric disorders - A comprehensive review

Mental illness is a hidden epidemic in modern science that has gradually spread worldwide. According to estimates from the World Health Organization (WHO), approximately 10% of the world's population suffers from various mental diseases each year. Worldwide, financial and health burdens on society are increasing annually. Therefore, understanding the different factors that can influence mental illness is required to formulate novel and effective treatments and interventions to combat mental illness. Gut microbiota, consisting of diverse microbial communities residing in the gastrointestinal tract, exert profound effects on the central nervous system through the gut-brain axis. The gut-brain axis serves as a conduit for bidirectional communication between the two systems, enabling the gut microbiota to affect emotional and cognitive functions. Dysbiosis, or an imbalance in the gut microbiota, is associated with an increased susceptibility to mental health disorders and psychiatric illnesses. Gut microbiota is one of the most diverse and abundant groups of microbes that have been found to interact with the central nervous system and play important physiological functions in the human gut, thus greatly affecting the development of mental illnesses. The interaction between gut microbiota and mental health-related illnesses is a multifaceted and promising field of study. This review explores the mechanisms by which gut microbiota influences mental health, encompassing the modulation of neurotransmitter production, neuroinflammation, and integrity of the gut barrier. In addition, it emphasizes a thorough understanding of how the gut microbiome affects various psychiatric conditions.

Effect of cesarean section on the risk of autism spectrum disorders/attention deficit hyperactivity disorder in offspring: a meta-analysis

PURPOSE

This study was conducted to investigate the relationship between cesarean section (CS) offspring and autism spectrum disorders (ASD)/attention deficit hyperactivity disorder (ADHD).

METHODS

Searching of the databases (PubMed, Web of Science, Embase, and Cochrane Library) for studies on the relationship between mode of delivery and ASD/ADHD until August 2022. The primary outcome was the incidence of ASD/ADHD in the offspring.

RESULTS

This meta-analysis included 35 studies (12 cohort studies and 23 case-control studies). Statistical results showed a higher risk of ASD (odds ratio (OR) = 1.25, P < 0.001) and ADHD (OR = 1.11, P < 0.001) in CS offspring compared to the VD group. Partial subgroup analysis showed no difference in ASD risk between CS and VD offspring in sibling-matched groups (OR = 0.98, P = 0.625). The risk of ASD was higher in females (OR = 1.66, P = 0.003) than in males (OR = 1.17, P = 0.004) in the CS offspring compared with the VD group. There was no difference in the risk of ASD between CS under regional anesthesia group and VD group (OR = 1.07, P = 0.173). However, the risk of ASD was higher in the CS offspring under general anesthesia than in the VD offspring (OR = 1.62, P < 0.001). CS offspring developed autism (OR = 1.38, P = 0.011) and pervasive developmental disorder-not otherwise specified (OR = 1.46, P = 0.004) had a higher risk than VD offspring, but there was no difference in Asperger syndrome (OR = 1.19, P = 0.115). Offspring born via CS had a higher incidence of ADHD in different subgroup analyses (sibling-matched, type of CS, and study design).

CONCLUSIONS

In this meta-analysis, CS was a risk factor for ASD/ADHD in offspring compared with VD.

Association of caesarean delivery with offspring health outcomes in full-cohort versus sibling-comparison studies: a comparative meta-analysis and simulation study

BACKGROUND

Full-cohort and sibling-comparison designs have yielded inconsistent results about the impacts of caesarean delivery on offspring health outcomes, with the effect estimates from the latter being more likely directed towards the null value. We hypothesized that the seemingly conservative results obtained from the sibling-comparison design might be attributed to inadequate adjustment for non-shared confounders between siblings, particularly maternal age at delivery.

METHODS

A systematic review and meta-analysis was first conducted. PubMed, Embase, and the Web of Science were searched from database inception to April 6, 2022. Included studies (1) examined the association of caesarean delivery, whether elective or emergency, with offspring health outcomes; (2) simultaneously conducted full-cohort and sibling-comparison analyses; and (3) reported adjusted effect estimates with 95% confidence intervals (95% CIs). No language restrictions were applied. Data were extracted by 2 reviewers independently. Three-level meta-analytic models were used to calculate the pooled odds ratios (ORs) and 95% CIs for caesarean versus vaginal delivery on multiple offspring health outcomes separately for full-cohort and sibling-comparison designs. Subgroup analyses were performed based on the method of adjustment for maternal age at delivery. A simulation study was then conducted. The simulated datasets were generated with some key parameters derived from the meta-analysis.

RESULTS

Eighteen studies involving 21,854,828 individuals were included. The outcomes assessed included mental and behavioral disorders; endocrine, nutritional and metabolic diseases; asthma; cardiorespiratory fitness; and multiple sclerosis. The overall pooled OR for estimates from the full-cohort design was 1.14 (95% CI: 1.11 to 1.17), higher than that for estimates from the sibling-comparison design (OR = 1.08; 95% CI: 1.02 to 1.14). Stratified analyses showed that estimates from the sibling-comparison design varied considerably across studies using different methods to adjust for maternal age at delivery in multivariate analyses, while those from the full-cohort design were rather stable: in studies that did not adjust maternal age at delivery, the pooled OR of full-cohort vs. sibling-comparison design was 1.10 (95% CI: 0.99 to 1.22) vs. 1.06 (95% CI: 0.85 to 1.31), in studies adjusting it as a categorical variable, 1.15 (95% CI: 1.11 to 1.19) vs. 1.07 (95% CI: 1.00 to 1.15), and in studies adjusting it as a continuous variable, 1.12 (95% CI: 1.05 to 1.19) vs. 1.12 (95% CI: 0.98 to 1.29). The severe underestimation bias related to the inadequate adjustment of maternal age at delivery in sibling-comparison analyses was fully replicated in the simulation study.

CONCLUSIONS

Sibling-comparison analyses may underestimate the association of caesarean delivery with multiple offspring health outcomes due to inadequate adjustment of non-shared confounders, such as maternal age at delivery. Thus, we should be cautious when interpreting the seemingly conservative results of sibling-comparison analyses in delivery-related studies.

Microbial Reprogramming in Obsessive-Compulsive Disorders: A Review of Gut-Brain Communication and Emerging Evidence

Obsessive-compulsive disorder (OCD) is a debilitating mental health disorder characterized by intrusive thoughts (obsessions) and repetitive behaviors (compulsions). Dysbiosis, an imbalance in the gut microbial composition, has been associated with various health conditions, including mental health disorders, autism, and inflammatory diseases. While the exact mechanisms underlying OCD remain unclear, this review presents a growing body of evidence suggesting a potential link between dysbiosis and the multifaceted etiology of OCD, interacting with genetic, neurobiological, immunological, and environmental factors. This review highlights the emerging evidence implicating the gut microbiota in the pathophysiology of OCD and its potential as a target for novel therapeutic approaches. We propose a model that positions dysbiosis as the central unifying element in the neurochemical, immunological, genetic, and environmental factors leading to OCD. The potential and challenges of microbial reprogramming strategies, such as probiotics and fecal transplants in OCD therapeutics, are discussed. This review raises awareness of the importance of adopting a holistic approach that considers the interplay between the gut and the brain to develop interventions that account for the multifaceted nature of OCD and contribute to the advancement of more personalized approaches.

Maternal and Early-Life Exposure to Antibiotics and the Risk of Autism and Attention-Deficit Hyperactivity Disorder in Childhood: a Swedish Population-Based Cohort Study

INTRODUCTION

Antibiotics represent the most common type of medication used during pregnancy and infancy. Antibiotics have been proposed as a possible factor in changes in microbiota composition, which may play a role in the aetiology of autism and attention deficit/hyperactivity disorder (ADHD). Our aim was to investigate the association between maternal and early-life antibiotic use and autism and ADHD in childhood.

METHODS

This Swedish nation-wide population-based cohort study included all first live singleton births (N = 483,459) between January 2006 and December 2016. The association of dispensed antibiotics with autism and ADHD in children aged ≤ 11 years was estimated by applying multivariable logistic regression and generalised estimating equations models.

RESULTS

Of the mothers, 25.9% (n = 125,106) were dispensed ≥1 antibiotic during the exposure period (from 3 months pre-conception to delivery), and 41.6% (n = 201,040) of the children received ≥ 1 antibiotic in early life (aged ≤ 2 years). Penicillin was the most prescribed antibiotic class (17.9% of mothers, 38.2% of children). Maternal antibiotic use was associated with an increased risk of autism [odds ratio (OR) = 1.16, 95% confidence interval (CI) 1.09-1.23] and ADHD (OR = 1.29, 95% CI 1.21-1.36) in childhood. Early-life exposure to antibiotics showed an even stronger association [autism (OR = 1.46, 95% CI 1.38-1.55); ADHD (OR = 1.90, 95% CI 1.80-2.00)]. Both maternal and childhood-exposure sub-analyses suggested a dose-response relationship.

CONCLUSION

Maternal and early-life antibiotic use was associated with an increased risk of autism and ADHD in childhood. However, differences were noted by exposure period and antibiotic classes.

Effect of mode of birth on development of mental disorders in the offspring

OBJECTIVE

Increasing rates of caesarean sections has led to concerns about long-term effects on the offspring's health, and it has been hypothesised that caesarean section induced differences in the child's microbiota could potentially increase the risk of mental disorders.

METHODS

Nationwide Danish cohort study of 2,196,687 births was conducted between 1980 and 2015, with 38.5 million observation-years. Exposure was 'Caesarean Section' and outcome was the child's risk of any mental disorder. Absolute and relative risks (RRs) were estimated using inverse probability weighting to adjust for age, calendar time and confounding variables while accounting for the competing risk of death.

RESULTS

Caesarean section (n = 364,908, 16.6%), compared to vaginal birth, was associated with a small RR increase of 8% (RR, 1.08; 95% CI, 1.04-1.13; n = 44,352) for the development of any in-patient psychiatric admission at age 36 for the offspring and with a small absolute risk difference of 0.47% (95% CI, 0.23-0.76). When looking at all in-patient, out-patient and emergency room psychiatric contacts among people born after 1995, the effect was diminished (RR, 1.04; 95% CI, 0.99-1.09; n = 15,211). The risk was comparable when comparing prelabour versus intrapartum caesarean section (RR, 0.98; 95% CI, 0.90-1.08) and acute versus planned caesarean section (RR, 1.00; 95% CI, 0.80-1.29).

CONCLUSION

Birth by caesarean section was associated with only a very slightly increased risk of any in-patient psychiatric admission for the offspring and diminished even further when including all psychiatric contacts. The very small associations observed may be explained by unmeasured confounding and is unlikely to be of substantial clinical relevance.

A Meta-Analysis on the Impact of Prenatal and Early Childhood Antimicrobial Use on Autism Spectrum Disorders

OBJECTIVE

To investigate the impact of prenatal and early childhood antimicrobial use on autism spectrum disorders (ASD).

DATA SOURCES

We searched PubMed and Embase databases for relevant studies from inception to August 2022.

STUDY SELECTION AND DATA EXTRACTION

Peer-reviewed, observational studies were all acceptable. Raw data were extracted into a predefined worksheet and quality analysis was performed using the Newcastle-Ottawa Scale.

DATA SYNTHESIS

Nineteen studies were identified in the meta-analysis. Prenatal antimicrobial exposure was not associated with ASD (P = 0.06 > 0.05), whereas early childhood antimicrobial exposure was associated with an increased odds ratio of ASD (OR = 1.17, 95% CI = [1.08-1.27], P value < 0.001). The sibling-matched analysis, with a very limited sample size, suggested that neither prenatal (P = 0.47 > 0.05) nor early childhood (P = 0.13 > 0.05) antimicrobial exposure was associated with ASD. Medical professionals may need to take the possible association into consideration when prescribing an antimicrobial in children.

CONCLUSIONS

Early childhood antimicrobial exposure could increase the incidence of ASD. In future studies, it would be necessary to control for confounding factors, such as genetic factors, parenteral age at birth, or low birthweight, to further validate the association.

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

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

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.

Role of Maternal Microbiota and Nutrition in Early-Life Neurodevelopmental Disorders

The rise in the prevalence of obesity and other related metabolic diseases has been paralleled by an increase in the frequency of neurodevelopmental problems, which has raised the likelihood of a link between these two phenomena. In this scenario, maternal microbiota is a possible linking mechanistic pathway. According to the "Developmental Origins of Health and Disease" paradigm, environmental exposures (in utero and early life) can permanently alter the body's structure, physiology, and metabolism, increasing illness risk and/or speeding up disease progression in offspring, adults, and even generations. Nutritional exposure during early developmental stages may induce susceptibility to the later development of human diseases via interactions in the microbiome, including alterations in brain function and behavior of offspring, as explained by the gut-brain axis theory. This review provides an overview of the implications of maternal nutrition on neurodevelopmental disorders and the establishment and maturation of gut microbiota in the offspring.

Insights into epidemiologic assessments of the microbiome and challenges in identifying microbiome relationships with adverse pregnancy outcomes

Purpose of review

We describe different methods for microbiome assessment and analysis and highlight some of the challenges of using omics data in epidemiologic studies of adverse pregnancy outcomes.

Recent findings

Human microbiomes are dynamic and vary by ancestry and geography. The composition and dynamics of the vaginal microbiome has been associated with risk of preterm birth.

Summary

There are several different methods for characterizing the microbiome. Choice of method depends on the research question and resources available. Added to known challenges of conducting and analyzing epidemiologic studies are the unique challenges associated with microbiome detection and analysis. The resulting omics assessments of human microbial communities have great potential to identify prognostics, diagnostics and potentially therapeutics for adverse pregnancy outcomes.

Early-life antibiotic use and risk of attention-deficit hyperactivity disorder and autism spectrum disorder: results of a discordant twin study

Background

Development of the gut-brain axis in early life may be disturbed by antibiotic use. It has been hypothesized that this disturbance may contribute to development of neurodevelopmental disorders, including autism spectrum disorder and attention-deficit hyperactivity disorder. We aimed to assess the association between antibiotic use in early life and the risk of developing attention-deficit hyperactivity disorder or autism spectrum disorder, while controlling for shared genetic and environmental factors in a discordant twin design.

Methods

We conducted a cohort study in twins (7–12 years; 25 781 twins) from the Netherlands Twin Register (NTR) and a replication study in the Childhood and Adolescent Twin Study in Sweden (CATSS; 7946 9-year-old twins). Antibiotic use was recorded before age 2 years. Attention-deficit hyperactivity disorder and autism spectrum disorder were parent-reported in the Netherlands Twin Register and register-based in the Childhood and Adolescent Twin Study in Sweden.

Results

Early-life antibiotic use was associated with increased risk of attention-deficit hyperactivity disorder development [pooled odds ratio (OR) 1.10, 95% confidence interval (CI) 1.02-1.17] and autism spectrum disorder (pooled OR 1.15, 95% CI 1.06-1.25) in a case-control design. When restricting to monozygotic twin pairs discordant for the outcome, associations disappeared for both disorders in both cohorts (attention-deficit hyperactivity disorder OR 0.90, 95% CI 0.48-1.69 and OR 0.80, 95% CI 0.37-1.76, and autism spectrum disorder OR 0.66, 95% CI 0.38-1.16 and OR 0.29, 95% CI 0.02-4.50, respectively).

Conclusions

Our findings suggest that the association between early-life antibiotic use and risk of attention-deficit hyperactivity and autism spectrum disorder may be confounded by shared familial environment and genetics.

Early Life Antibiotic Exposure and the Subsequent Risk of Autism Spectrum Disorder and Attention Deficit Hyperactivity Disorder: A Systematic Review and Meta-Analysis

This study was conducted to assess this association between early life antibiotic exposure and the risk of autism spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD) in later life. The results showed that early life antibiotic exposure was associated with an increased risk of ASD (OR = 1.13, 95% confidence interval (CI): 1.07-1.21) or ADHD (OR = 1.18, 95% CI: 1.1-1.27). However, this association for ASD (OR = 1.04, 95% CI: 0.97-1.11) or ADHD (OR = 0.98, 95% CI: 0.94-1.02) disappeared when data from sibling-matched studies were pooled. The statistically significant association between early life antibiotic exposure and ASD or ADHD in later life can be partially explained by unmeasured genetic and familial confounding factors.

Microbiota and Microglia Interactions in ASD

Autism spectrum disorders (ASD) are serious, highly variable neurodevelopmental disorders, commonly characterized by the manifestation of specific behavioral abnormalities, such as stereotypic behaviors and deficits in social skills, including communication. Although the neurobiological basis for ASD has attracted attention in recent decades, the role of microglial cells, which are the main resident myeloid cell population in the brain, is still controversial and underexplored. Microglia play several fundamental roles in orchestrating brain development and homeostasis. As such, alterations in the intrinsic functions of these cells could be one of the driving forces responsible for the development of various neurodevelopmental disorders, including ASD. Microglia are highly sensitive to environmental cues. Amongst the environmental factors known to influence their intrinsic functions, the gut microbiota has emerged as a central player, controlling both microglial maturation and activation. Strikingly, there is now compelling data suggesting that the intestinal microbiota can play a causative role in driving the behavioural changes associated with ASD. Not only is intestinal dysbiosis commonly reported in ASD patients, but therapies targeting the microbiome can markedly alleviate behavioral symptoms. Here we explore the emerging mechanisms by which altered microglial functions could contribute to several major etiological factors of ASD. We then demonstrate how pre- and postnatal environmental stimuli can modulate microglial cell phenotype and function, underpinning the notion that reciprocal interactions between microglia and intestinal microbes could play a crucial role in ASD aetiology.

Assessment of Cesarean Delivery and Neurodevelopmental and Psychiatric Disorders in the Children of a Population-Based Swedish Birth Cohort

IMPORTANCE

Recent studies suggest that cesarean delivery (CD) is associated with increased risk of neurodevelopmental disorders in children, although they were unable to control for indications for CD or familial confounding beyond full siblings.

OBJECTIVE

To examine the association between CD and neurodevelopmental and psychiatric disorders in children.

DESIGN, SETTING, AND PARTICIPANTS

This Swedish register-based cohort study included 1 179 341 term-birth singletons born between January 1, 1990, and December 31, 2003, and followed up through December 31, 2013. All individuals were linked to their full siblings, maternal and paternal half siblings, and maternal full cousins. Statistical analyses were performed from September 26, 2019, to January 16, 2021.

EXPOSURES

Birth by CD recorded at birth, stratified into planned and intrapartum CD.

MAIN OUTCOMES AND MEASURES

Registered diagnoses of neurodevelopmental disorders, including attention-deficit/hyperactivity disorder (ADHD), autism spectrum disorders (ASD), intellectual disability, tic disorders, communication disorders, learning disorders, and any neurodevelopmental disorder; and psychiatric disorders, including anxiety disorders, obsessive-compulsive disorder, depressive disorders, eating disorders, bipolar disorders, psychotic disorders, and any psychiatric disorder.

RESULTS

Of 1 179 341 individuals, 1 048 838 (533 140 boys [50.8%]) were delivered vaginally, 59 514 (30 138 boys [50.6%]) were delived via planned CD, and 70 989 (39 191 boys [55.2%]) were delivered via intrapartum CD. Mean (SD) age at follow-up was 17.7 (4.1) years for vaginal delivery, 16.6 (4.2) years for planned CD, and 16.8 (4.1) years for intrapartum CD. Compared with vaginal delivery, and after controlling for measured covariates (parental and neonatal characteristics, maternal comorbidities, and pregnancy complications), CD was associated with higher risk in children of any neurodevelopmental disorder (planned CD, hazard ratio [HR], 1.17; 95% CI, 1.13-1.22; intrapartum CD, HR, 1.10; 95% CI, 1.05-1.14), ADHD (planned CD, HR, 1.17; 95% CI, 1.12-1.23; intrapartum CD, HR, 1.10; 95% CI, 1.05-1.15), and intellectual disability (planned CD, HR, 1.26; 95% CI, 1.14-1.39; intrapartum CD, HR, 1.17; 95% CI, 1.06-1.28). Only planned CD was associated with a higher risk of ASD (HR, 1.20; 95% CI, 1.10-1.31), communication disorders (HR, 1.14; 95% CI, 1.02-1.28), and learning disorders (HR, 1.15; 95% CI, 1.01-1.30). Cesarean delivery was not associated with the remaining disorders. The associations between CD and any neurodevelopmental disorder, ADHD, ASD, and intellectual disability attenuated in full cousins and paternal half siblings, and further attenuated (became nonsignificant) in maternal half siblings and full siblings (risk of any neurodevelopmental disorder in full siblings, planned CD, HR, 0.93; 95% CI, 0.81-1.06; intrapartum CD, HR, 1.07; 95% CI, 0.96-1.21).

CONCLUSIONS AND RELEVANCE

The findings of this study suggest that the association between CD and increased risk of neurodevelopmental disorders in the children was most likely explained by unmeasured familial confounding.

Targeting the gut microbiome: A brief report on the awareness, practice, and readiness to engage in clinical interventions in Qatar

BACKGROUND

There has been a growing global interest in the role of gut microbiota in the pathogenesis of diseases and the potentials of targeting the microbiome in clinical interventions. Very few clinical studies in Qatar focused on gut microbiome. This study aimed to assess the awareness of healthcare professionals, scientists, and the general public on the role of gut microbiota in health and diseases and, more specifically, in disorders of the gut-brain axis such as neurodevelopmental disorders (NDDs) or gastrointestinal (GI) disorders. It also aimed to evaluate the readiness of the population to engage in clinical trials involving dietary interventions or fecal transplants.

METHODS

A total of 156 participants were recruited to answer questionnaires-from healthcare professionals and scientists (HSs; n = 44) and the general public (n = 112). Participants from the general public self-reported their diagnosis of NDDs-autism or attention deficit hyperactivity disorder (n = 36)-or GI diseases or disorders (n = 18) or as having none of them (n = 58). Two questionnaires for HSs and for the general public were distributed, and basic descriptive and statistical analyses were conducted using the Fisher's exact test.

RESULTS

Among the participating HSs, 95% admitted that they had minimum to no knowledge on the role of gut microbes in health and diseases, and only 15.9% felt that their peers were knowledgeable about it. Nevertheless, 97.7% of HSs thought that gut microbiota should be considered when devising treatment plans as 79.1% believed that gut dysbiosis is involved in the pathogenesis of diseases. For the general public, 54% stated that they have read about studies on the potential benefits of microbes in the prevention, treatment, and management of diseases, with a higher proportion of them belonging to the GI group (p = 0.0523). The GI group was also more aware of the existence of the use of fecal transplants for treating their condition (p = 0.01935). Awareness was also reflected in participants' attempts to engage in dietary changes, as 40% tried a dietary intervention, which has noticeably changed their or their child's symptoms. This study reported a highly significant association between being exposed to multiple antibiotic courses before three years of age and being part of the NDD group (p = 0.0003). Public readiness to engage in interventions that target the gut microbiome, such as intensive dietary interventions or even fecal transplants, was perceived by HSs to be lower than what was stated by the public, with 87.96% of public being ready to engage in intensive dietary interventions and 66.98% in fecal transplants.

CONCLUSION

The study revealed that the role of gut microbes in health and diseases, and especially through the gut-brain axis, is still unclear in both the scientific community and general public. While acknowledging the importance of gut microbes, the lack of information regarding the link between lifestyle and gut microbes is considered to hold the public in the precontemplation/contemplation stages of the transtheoretical model of behavioral change. An interdisciplinary approach to new knowledge produced by microbiome studies is needed to run awareness campaigns and continue professional development activities on the benefits of lifestyle-based modulation of gut microbiome, thus engaging the general public in lifestyle changes and facilitating clinical research in human microbiome investigations in Qatar.

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.

Environmental Tobacco Smoke Exposure and Breastfeeding Duration Influence the Composition and Dynamics of Gut Microbiota in Young Children Aged 0-2 Years

The colonization characteristics of infant gut microbiota are influenced by many factors at various stages, but few studies have explored the longitudinal effects of environmental tobacco smoke exposure and quantitative breastfeeding duration on young children' gut microbiota. We explored the effects of smoke exposure and breastfeeding duration on gut microbiota by following 37 maternal and children pairs in China for 2 years. We collected the demographic information, frequency of smoke exposure, breastfeeding duration, and fecal samples (mothers in the late pregnancy and infants at 6, 12, and 24 months), and analyzed the microbiota results using the V3-V4 gene sequence of 16S rRNA. The diversity of gut microbiota in children was the highest at 24 months and most similar to that in mothers. Breastfeeding duration was positively correlated with Lactobacillus and negatively correlated with Clostridium_sensu_stricto_1. The α diversity of microbiota and the relative abundance of [Ruminococcus]_gnavus_group was higher in the non-smoke exposed group. The higher the smoke exposure, the higher the relative abundance of Megasphaera. Prolonged breastfeeding and reduced smoke exposure are beneficial to the diversity and composition of gut microbiota in young children.

Analysis of Factors That May Affect the Effect of Atropine 0.01% on Myopia Control

Children respond differently to atropine treatment, and predicting patient factors associated with better myopia control is important. Therefore, we aimed to evaluate factors related to myopia progression in Chinese children treated with atropine 0.01%. This retrospective study included 133 children who were administered atropine 0.01% eyedrops every night for 1 year. Enrolled children were examined at follow-up visits at 3 and 6 months, and 1 year. The primary outcome was clinically significant myopia progression (over a -0.75 diopter (D) increase in spherical equivalent (SE)). Multivariate logistic analysis was used to identify predictive factors for myopia progression. The mean baseline SE was -3.92 ± 2.76D, and the average increase in SE and axial length at 1 year from baseline were -0.55 ± 0.57D and 0.43 ± 0.52 mm, respectively. The risk of myopia progression significantly increased in children whose mothers had moderate myopia of less than -6D compared to that in children whose mothers had no history of myopia (odd ratio [OR] = 2.76, 95% confidence interval [CI]: 1.06 to 7.19, P = 0.0382). Birth by cesarean section was also a risk factor for myopia progression (odd ratio [OR] = 2.35, 95% CI: 1.30 to 4.27, P = 0.0048). The correlation between SE and treatment efficiency was linear, and the risk of myopia progression significantly decreased with increasing SE. Atropine 0.01% controlled myopia more effectively in children with higher myopia, who were delivered naturally, and whose mothers had no genetic background of myopia.

Exploring the usefulness of Lexis diagrams for quality improvement

BACKGROUND

Visualization is important to aid practitioners in understanding local care processes and drive quality improvement (QI). Important aspects include timely feedback and ability to plot data over time. Moreover, the complexity of care also needs to be understood, as it affects the variation of care processes. However, there is a lack of QI methods visualizing multiple, related factors such as diagnosis date, death date, and cause of death to unravel their complexity, which is necessary to understand processes related to survival data. Lexis diagrams visualize individual patient processes as lines and mark additional factors such as key events. This study explores the potential of Lexis diagrams to support QI through survival data analysis, focusing on feedback, timeliness, and complexity, in a gynecological cancer setting in Sweden.

METHODS

Lexis diagrams were produced based on data from a gynecological cancer quality registry (4481 patients). The usefulness of Lexis diagrams was explored through iterative data identification and analysis through semi-structured dialogues between the researcher and domain experts (clinically active care process owners) during five meetings. Visualizations were produced and adapted by the researcher between meetings, based on the dialogues, to ensure clinical relevance, resulting in three relevant types of visualizations.

RESULTS

Domain experts identified different uses depending on diagnosis group and data visualization. Key results include timely feedback through close-to-real-time visualizations, supporting discussion and understanding of trends and hypothesis-building. Visualization of care process complexity facilitated evaluation of given care. Combined visualization of individual and population levels increased patient focus and may possibly also function to motivate practitioners and management.

CONCLUSION

Lexis diagrams can aid understanding of survival data, triggering important dialogues between care givers and supporting care quality improvement and new perspectives, and can therefore complement survival curves in quality improvement.

Early Life Exposure to Antibiotics and Autism Spectrum Disorders: A Systematic Review

We systematically reviewed evidence from observational studies on the associations between autism spectrum disorders (ASD) and early-life antibiotic exposure. Eleven articles were included in the review. Prenatal antibiotic exposure was associated with a slightly increased risk of ASD in two cohort studies on overlapping populations and in one case–control study; in three other case–control studies, no significant association was found. One cohort study found a slightly reduced risk of ASD after postnatal antibiotic exposure, while two other cohort studies on overlapping populations and three case–control studies reported an increased risk. Meta-analysis of the eligible studies showed no significant associations. Current data are conflicting and do not conclusively support the hypothesis that early-life antibiotic exposure is associated with subsequent ASD development.

Gut microbiome: An intermediary to neurotoxicity

There is growing recognition that the gut microbiome is an important regulator for neurological functions. This review provides a summary on the role of gut microbiota in various neurological disorders including neurotoxicity induced by environmental stressors such as drugs, environmental contaminants, and dietary factors. We propose that the gut microbiome remotely senses and regulates CNS signaling through the following mechanisms: 1) intestinal bacteria-mediated biotransformation of neurotoxicants that alters the neuro-reactivity of the parent compounds; 2) altered production of neuro-reactive microbial metabolites following exposure to certain environmental stressors; 3) bi-directional communication within the gut-brain axis to alter the intestinal barrier integrity; and 4) regulation of mucosal immune function. Distinct microbial metabolites may enter systemic circulation and epigenetically reprogram the expression of host genes in the CNS, regulating neuroinflammation, cell survival, or cell death. We will also review the current tools for the study of the gut-brain axis and provide some suggestions to move this field forward in the future.

Association of Cesarean Delivery With Risk of Neurodevelopmental and Psychiatric Disorders in the Offspring: A Systematic Review and Meta-analysis

Importance

Birth by cesarean delivery is increasing globally, particularly cesarean deliveries without medical indication. Children born via cesarean delivery may have an increased risk of negative health outcomes, but the evidence for psychiatric disorders is incomplete.

Objective

To evaluate the association between cesarean delivery and risk of neurodevelopmental and psychiatric disorders in the offspring.

Data Sources

Ovid MEDLINE, Embase, Web of Science, and PsycINFO were searched from inception to December 19, 2018. Search terms included all main mental disorders in the Diagnostic and Statistical Manual of Mental Disorders (Fifth Edition).

Study Selection

Two researchers independently selected observational studies that examined the association between cesarean delivery and neurodevelopmental and psychiatric disorders in the offspring.

Data Extraction and Synthesis

Two researchers independently extracted data according to Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) and Meta-analysis of Observational Studies in Epidemiology (MOOSE) reporting guidelines and assessed study quality using the Newcastle-Ottawa Scale. Random-effects meta-analyses were used to pool odds ratios (ORs) with 95% CIs for each outcome. Sensitivity and influence analyses tested the robustness of the results.

Main Outcomes and Measures

The ORs for the offspring with any neurodevelopmental or psychiatric disorder who were born via cesarean delivery compared with those were born via vaginal delivery.

Results

A total of 6953 articles were identified, of which 61 studies comprising 67 independent samples were included, totaling 20 607 935 deliveries. Compared with offspring born by vaginal delivery, offspring born via cesarean delivery had increased odds of autism spectrum disorders (OR, 1.33; 95% CI, 1.25-1.41; I2 = 69.5%) and attention-deficit/hyperactivity disorder (OR, 1.17; 95% CI, 1.07-1.26; I2 = 79.2%). Estimates were less precise for intellectual disabilities (OR, 1.83; 95% CI, 0.90-3.70; I2 = 88.2%), obsessive-compulsive disorder (OR, 1.49; 95% CI, 0.87-2.56; I2 = 67.3%), tic disorders (OR, 1.31; 95% CI, 0.98-1.76; I2 = 75.6%), and eating disorders (OR, 1.18; 95% CI, 0.96-1.47; I2 = 92.7%). No significant associations were found with depression/affective psychoses or nonaffective psychoses. Estimates were comparable for emergency and elective cesarean delivery. Study quality was high for 82% of the cohort studies and 50% of the case-control studies.

Conclusions and Relevance

The findings suggest that cesarean delivery births are associated with an increased risk of autism spectrum disorder and attention-deficit/hyperactivity disorder, irrespective of cesarean delivery modality, compared with vaginal delivery. Future studies on the mechanisms behind these associations appear to be warranted.