Association between caesarean section and childhood obesity: a systematic review and meta-analysis

The association between caesarean section delivery and obesity at age 17 years. Evidence from a longitudinal cohort study in the United Kingdom

BACKGROUND

Childhood and adolescent obesity are major, preventable public health concerns. Studies to date are inconclusive regarding an association between caesarean section (CS) delivery and offspring obesity, with fewer studies conducted in late adolescence. This study examined the association between CS delivery, with a specific focus on planned CS, and induction of labour and adolescent body mass index (BMI) and body fat percentage (BF%) at age 17 years.

METHODS

Data on 8,880 mother-child pairs from the United Kingdom Millennium Cohort Study were analysed. The exposures were mode of delivery (normal vaginal delivery (VD) (reference), assisted VD, planned CS and emergency CS) and mode of delivery by induction of labour status. Crude and adjusted binary logistic regression and linear regression models were fitted examining BMI and BF% at age 17 years respectively, adjusting for several potential confounders.

RESULTS

Adolescents born by CS did not have an elevated BMI or BF% compared to those born by normal VD. The fully adjusted results for overweight and obesity in children born by planned CS, compared to VD, were 1.05 (95% CI: 0.86-1.28) and 0.94 (95% CI: 0.72-1.23), respectively. The results were similar for the associations between CS and BF%, and between induction of labour and BMI.

CONCLUSION

Overall, this large longitudinal study did not support an association between CS or induction of labour and overweight, obesity or BF%. It is possible that previously reported associations are due to residual or unmeasured confounding and/or underlying indications for CS delivery.

The Accumulative Effect of Multiple Postnatal Risk Factors with the Risk of Being Overweight/Obese in Late Childhood

Most past studies focused on the associations of prenatal risk factors with the risks of childhood overweight/obesity. Instead, more postnatal risk factors are modifiable, with less knowledge of their cumulative effects on childhood obesity. We analyzed data of 1869 children in an Australian birth cohort. Key postnatal risk factors included: maternal and paternal overweight/obesity during the child's infancy, tobacco exposure, low family socioeconomic score, breastfeeding duration < 6 months, early introduction of solid foods, and rapid weight gain during infancy. The risk score was the sum of the number of risk factors. The primary outcome is overweight/obesity in late childhood (11-12 years); secondary outcomes are high-fat mass index (FMI), body fat percentage (BF%), and waist-to-height ratio (WHtR). Poisson regression models were used in the analyses. Children with higher risk scores had higher risks of overweight/obesity (p-for-trends < 0.001). After adjusting covariates, compared with those with 0-1 risk factors, children with 4-6 risk factors had 4.30 (95% confidence interval: 2.98, 6.21) times higher risk of being overweight/obesity; the relative risks for high FMI, BF%, and WHtR were 7.31 (3.97, 13.45), 4.41 (3.00, 6.50), and 6.52 (3.33, 12.74), respectively. Our findings highlighted that multiple postnatal risk factors were associated with increased risks of being overweight/obesity in late childhood.

What causes obesity in children and adolescents?

OBJECTIVE

To present the different aspects that may be involved in the genesis and maintenance of obesity in children and adolescents.

DATA SOURCE

Narrative review of articles published in the PubMed, Scielo, Lilacs, Scopus and Google Scholar databases, using the search terms: overweight, obesity, pre-conception, prenatal, infants, schoolchildren, children, and adolescents. The search was conducted in studies written in Portuguese, English and Spanish, including narrative, integrative or systematic reviews, meta-analyses, cross-sectional, case-control and cohort studies, published between 2003 and 2023.

DATA SYNTHESIS

A total of 598 studies were initially screened and 60 of them, which showed the main biopsychosocial aspects related to greater risks of excessive adiposity in the pediatric age, were included in the review. The data were presented taking into account the incidence of risk factors and their consequences in six periods: pre-conception, pre-natal, infant, preschool, school age, and adolescence.

CONCLUSIONS

The causal factors described in the scientific literature that have been shown to be related to obesity in childhood and adolescence are presented.

Fecal transplant from vaginally seeded infants decreases intraabdominal adiposity in mice

Exposing C-section infants to the maternal vaginal microbiome, coined "vaginal seeding", partially restores microbial colonization. However, whether vaginal seeding decreases metabolic disease risk is unknown. Therefore, we assessed the effect of vaginal seeding of human infants on adiposity in a murine model. Germ-free mice were colonized with transitional stool from human infants who received vaginal seeding or control (placebo) seeding in a double-blind randomized trial. There was a reduction in intraabdominal adipose tissue (IAAT) volume in male mice that received stool from vaginally seeded infants compared to control infants. Higher levels of isoleucine and lower levels of nucleic acid metabolites were observed in controls and correlated with increased IAAT. This suggests that early changes in the gut microbiome and metabolome caused by vaginal seeding have a positive impact on metabolic health.

Lactobacillus-derived indole-3-lactic acid ameliorates colitis in cesarean-born offspring via activation of aryl hydrocarbon receptor

Cesarean section (CS) delivery is known to disrupt the transmission of maternal microbiota to offspring, leading to an increased risk of inflammatory bowel disease (IBD). However, the underlying mechanisms remain poorly characterized. Here, we demonstrate that CS birth renders mice susceptible to dextran sulfate sodium (DSS)-induced colitis and impairs group 3 innate lymphoid cell (ILC3) development. Additionally, CS induces a sustained decrease in Lactobacillus abundance, which subsequently contributes to the colitis progression and ILC3 deficiency. Supplementation with a probiotic strain, L. acidophilus, or its metabolite, indole-3-lactic acid (ILA), can attenuate intestinal inflammation and restore ILC3 frequency and interleukin (IL)-22 level in CS offspring. Mechanistically, we indicate that ILA activates ILC3 through the aryl hydrocarbon receptor (AhR) signaling. Overall, our findings uncover a detrimental role of CS-induced gut dysbiosis in the pathogenesis of colitis and suggest L. acidophilus and ILA as potential targets to re-establish intestinal homeostasis in CS offspring.

Association of cesarean section with asthma in children/adolescents: a systematic review and meta-analysis based on cohort studies

BACKGROUND

Whether cesarean section (CS) is a risk factor for asthma in offspring is controversial. The purpose of this study was to investigate the association between CS and asthma in children/adolescents.

METHODS

Pubmed, Embase, Web of Science, and Cochrane Library electronic databases were searched for cohort studies on the relationship between mode of delivery and asthma in children/adolescents up to February 2023. Birth via CS was considered an exposure factor. Asthma incidence was taken as a result.

RESULTS

Thirty-five cohort studies (thirteen prospective and twenty-two retrospective cohort studies) were included. The results showed that the incidence of asthma was higher in CS offspring (odds ratio (OR) = 1.18, P < 0.001) than in the vaginal delivery (VD) group. Partial subgroup analyses showed a higher incidence of asthma in female offspring born via CS (OR = 1.26, P < 0.001) compared with the VD group, while there was no difference in males (OR = 1.07, P = 0.325). Asthma incidence was higher in CS offspring than in the VD group in Europe (OR = 1.20, P < 0.001), North America (OR = 1.15, P < 0.001), and Oceania (OR = 1.06, P = 0.008). This trend was not found in the Asian population (OR = 1.17, P = 0.102). The incidence of atopic asthma was higher in offspring born via CS (OR = 1.14, P < 0.001) compared to the VD group. The CS group had a higher incidence of persistent asthma, but the difference did not reach statistical significance (OR = 1.15, P = 0.063).

CONCLUSION

In this meta-analysis, CS may be a risk factor for asthma in offspring children/adolescents compared with VD. The relationship between CS and asthma was influenced by sex and region.

Evaluating the association between caesarean delivery and weight status in early childhood in a Japanese birth cohort study

To examine whether the prevailing hypothesis of an association between caesarean section (CS) delivery method and increased weight status in early childhood is observed in Japanese. A total of 1277 mother-infant pairs from a prospective hospital-based mother-infant birth cohort that recruited women in their first trimester from May 2010 to November 2013 were included. We assessed the relationship between delivery method and weight status of delivered children at 1, 3 and 6 years of age. In total, 366 children (28.7%) were delivered by CS. Delivery by CS was not associated with body mass index (BMI) z-score (≥ 75 percentile) at age 1 year, (odds ratio (OR) 0.97, 95% confidence interval (CI) 0.69-1.36), 3 years (OR 0.98, 95% CI 0.67-1.42), and 6 years (OR 0.71, 95% CI 0.45-1.12), and also showed no association with low weight status (< 25th percentile). Supplemental evaluations addressing the influence of preterm births, pre-pregnancy BMI, emergency CS, and modification by breastfeeding were consistent with the primary analyses. Our findings do not support the hypothesis that children born by CS are at risk of being overweight in childhood among the Japanese population.

Microbiome analysis of maternal and neonatal microbial communities associated with the different delivery modes based on 16S rRNA gene amplicon sequencing

OBJECTIVE

With the rising number of cases of non-vaginal delivery worldwide, scientists have been concerned about the influence of the different delivery modes on maternal and neonatal microbiomes. Although the birth rate trend is decreasing rapidly in Taiwan, more than 30 percent of newborns are delivered by caesarean section every year. However, it remains unclear whether the different delivery modes could have a certain impact on the postpartum maternal microbiome and whether it affects the mother-to-newborn vertical transmission of bacteria at birth.

MATERIALS AND METHODS

To address this, we recruited 30 mother-newborn pairs to participate in this study, including 23 pairs of vaginal delivery (VD) and seven pairs of caesarean section (CS). We here investigate the development of the maternal prenatal and postnatal microbiomes across multiple body habitats. Moreover, we also explore the early acquisition of neonatal gut microbiome through a vertical multi-body site microbiome analysis.

RESULTS AND CONCLUSION

The results indicate that no matter the delivery mode, it only slightly affects the maternal microbiome in multiple body habitats from pregnancy to postpartum. On the other hand, about 95% of species in the meconium microbiome were derived from one of the maternal body habitats; notably, the infants born by caesarean section acquire bacterial communities resembling their mother's oral microbiome. Consequently, the delivery modes play a crucial role in the initial colonization of the neonatal gut microbiome, potentially impacting children's health and development.

Maternal Bacterial Engraftment in Multiple Body Sites of Cesarean Section Born Neonates after Vaginal Seeding-a Randomized Controlled Trial

Children delivered by elective, prelabor Cesarean section (C-section) are not exposed to the birth canal microbiota and, in relation to vaginally delivered children, show altered microbiota development. Perturbed microbial colonization during critical early-life windows of development alters metabolic and immune programming and is associated with an increased risk of immune and metabolic diseases. In nonrandomized studies, vaginal seeding of C-section-born neonates partially restores their microbiota colonization to that of their vaginally delivered counterparts, but without randomization, confounding factors cannot be excluded. In a double-blind, randomized, placebo-controlled trial, we determined the effect of vaginal seeding versus placebo seeding (control arm) on the skin and stool microbiota of elective, prelabor C-section-born neonates (n = 20) at 1 day and 1 month after birth. We also examined whether there were between-arm differences in engraftment of maternal microbes in the neonatal microbiota. In relation to the control arm, vaginal seeding increased mother-to-neonate microbiota transmission and caused compositional changes and a reduction in alpha diversity (Shannon Index) of the skin and stool microbiota. The neonatal skin and stool microbiota alpha diversity when maternal vaginal microbiota is provided is intriguing and highlights the need of larger randomized studies to determine the ecological mechanisms and effects of vaginal seeding on clinical outcomes. IMPORTANCE Children delivered by elective C-section are not exposed to the birth canal and show altered microbiota development. Impairing microbial colonization during early life alters metabolic and immune programming and is associated with an increased risk of immune and metabolic diseases. In a double-blind, randomized, placebo-controlled trial, we determined the effect of vaginal seeding on the skin and stool microbiota of elective C-section born neonates and found that vaginal seeding increased mother-to-neonate microbiota transmission and caused compositional changes and a reduction in the skin and stool microbiota diversity. The reduction of neonatal skin and stool microbiota diversity when maternal vaginal microbiota is provided is intriguing and highlights the need of larger randomized studies to determine the ecological mechanisms and effects of vaginal seeding on clinical outcomes.

Association between Cesarean section and neurodevelopmental disorders in a Japanese birth cohort: the Japan Environment and Children's Study

BACKGROUND

The long-term effects of a Cesarean section (CS) birth on child neurodevelopment are of increasing interest. In this study, we examined the associations between mode of delivery and presence of neurodevelopmental disorders in toddlers. Moreover, given that the prevalence of several neurodevelopmental disorders such as autism spectrum disorder (ASD) is known to differ by sex, we also investigated these associations separately in male and female toddlers.

METHODS

We investigated 65,701 mother-toddler pairs from the Japan Environment and Children's Study, a nationally representative children's cohort study. To investigate the associations between mode of delivery (CS or vaginal delivery) and neurodevelopmental disorders (motor delay, intellectual disability, and ASD) in 3-year-old toddlers as a whole and stratified by sex, we used logistic regression models to calculate adjusted odds ratios (aORs) with 95% confidence intervals (CIs).

RESULTS

The morbidity of ASD at age 3 years was higher for children delivered by CS than those delivered vaginally (aOR 1.38, 95% CI 1.04-1.83). However, no such difference was evident in the case of motor delay or intellectual disability (aOR 1.33, 95% CI 0.94-1.89; aOR 1.18, 95% CI 0.94-1.49, respectively). In the analysis by sex, CS was not associated with increased risk of any of the neurodevelopmental disorders in males, but it was associated with increased risks of motor delay (aOR 1.88, 95% CI 1.02-3.47) and ASD (aOR 1.82, 95% CI 1.04-3.16) in females.

CONCLUSIONS

This study provides evidence of significant associations between mode of delivery and neurodevelopmental disorders in early childhood. Females may be more sensitive to the effects of CS than males.

Caesarean-section delivery and caries risk of 3-year-old Chinese children: a retrospective cohort study

BACKGROUND

Caesarean-section (C-section) may influence children's long-term health by affecting bacterial colonization. However, few studies have focused on the association between C-section delivery (CSD) and dental caries, and previous conclusions have been conflicting. This study aimed to explore whether CSD would increase the risk of early childhood caries (ECC) in preschool children in China.

METHODS

This study was a retrospective cohort study. Three-year-old children with full primary dentition were included through the medical records system. Children in the nonexposure group were vaginally delivered (VD), while children in the exposure group were delivered through C-section. The outcome was the occurrence of ECC. After agreeing to participate in this study, guardians of included children completed a structured questionnaire on maternal sociodemographic factors, children's oral hygiene and feeding habits. The chi-square test was used to determine differences in the prevalence and severity of ECC between the CSD and VD groups and to analyse the prevalence of ECC according to sample characteristics. Subsequently, potential risk factors for ECC were preliminarily identified through univariate analysis, and the adjusted odds ratios (ORs) were further calculated through multiple logistic regression analysis after controlling for confounding factors.

RESULTS

The VD group included 2115 participants while CSD group included 2996 participants. The prevalence of ECC was higher in CSD children than in VD children (27.6% vs. 20.9%, P < 0.05), and the severity of ECC in CSD children was higher (mean number of decayed, missing, and filled teeth, dmft: 2.1 vs. 1.7, P < 0.05). CSD was a risk factor for ECC in 3-year-old children (OR = 1.43, 95% CI = 1.10-2.83). In addition, irregular tooth brushing and always prechewing children's food were risk factors for ECC (P < 0.05). Low maternal educational attainment (high school or below) or socioeconomic status (SES-5) may also increase the prevalence of ECC in preschool children and CSD children (P < 0.05).

CONCLUSIONS

CSD would increase the risk of ECC in 3-year-old Chinese children. Paediatric dentists should devote more attention to the development of caries in CSD children. Obstetricians should also prevent excessive and unnecessary CSD.

Caesarean section and childhood obesity at age 3 years derived from the Japan Environment and Children's Study

Caesarean section (CS) birth is widely reported to be a risk factor for childhood obesity. Although susceptibility to childhood obesity is influenced by race and ethnicity, it is unclear whether this risk of childhood obesity with CS birth also applies in the Japanese population. We investigated the impact of CS birth on obesity at 3 years of age in Japanese children. We obtained data from 60,769 mother-toddler pairs in the Japan Environment and Children's Study, a large-scale birth cohort study. Obesity was determined by body mass index measured at 3 years of age. Analysis revealed that 11,241 toddlers (18.5%) had a CS birth and that 4912 toddlers (8.1%) were obese. The adjusted risk ratio for obesity at 3 years of age when born by CS compared with vaginal delivery, estimated using inverse probability of treatment weighting, was 1.16 (95% confidence interval 1.08-1.25). These results suggest that CS birth modestly increases the risk of obesity at 3 years of age in Japanese children.

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.

Caesarean Section Delivery Is Associated with Childhood Overweight and Obesity, Low Childbirth Weight and Postnatal Complications: A Cross-Sectional Study

Background and Objectives: In the last decades, simultaneously increasing trends have been recorded for both caesarean section delivery and childhood overweight/obesity around the world, which are considered serious public health concerns, negatively affecting child health. Aim: The present study aims to investigate whether caesarean section is associated with the increased rates of childhood overweight/obesity, low childbirth anthropometric indices and postnatal complications in pre-school age. Materials and Methods: This is a cross-sectional study in which 5215 pre-school children aged 2–5 years old were enrolled from nine different Greek regions after applying specific inclusion and exclusion criteria. Non-adjusted and adjusted statistical analysis was performed to assess the impact of caesarean section in comparison to vaginal delivery. Results: Children delivered by caesarean section were significantly more frequently overweight or obese at the age of 2–5 years, also presenting a higher prevalence of low birth weight, length and head circumference. Caesarean section was also associated with higher incidence of asthma and diabetes type I at the age of 2–5 years. In a multivariate analysis, caesarean section increased the risk of childhood overweight/obesity and low childbirth anthropometric indices even if adjusting for several childhood and maternal confounding factors. Conclusions: Increasing trends were recorded for both caesarean section delivery and childhood overweight/obesity, which are considered serious public health concerns. Caesarean section independently increased childhood overweight/obesity in pre-school age, highlighting the emergent need to promote health policies and strategies to inform future mothers about its short and long-term risks and that this mode of delivery should preferably be performed only when there are strong medical recommendations in emergency obstetric conditions.

Overweight and Obesity in Adult Birth by Cesarean Section: A Systematic Review With Meta-analysis

CONTEXT

Overweight/obesity is one of the most important health problems. Birth by cesarean section has been shown to influence long-term health outcomes including obesity.

OBJECTIVE

The aim of this systematic review-meta-analysis is to update acknowledgment of the increased risk of cesarean section on offspring's overweight/obesity.

METHODS

This study follows the PRISMA guidelines. A systematic literature search was conducted on Scopus, PubMed, and Web of Science; we have selected all the articles published until January 2, 2022. For inclusion, studies must have reported either (i) both birth by cesarean section and adult (≥18 years) offspring's body mass index; (ii) cohort or case-control study design; and (iii) a risk estimate. Heterogeneity testing was performed using Cochran's Q and I2 statistics. Publication bias was assessed by the Egger test and the Begg test. Meta-analysis was performed through a random-effects model.

RESULTS

Twelve studies with a combined population of 180 065 subjects were included in the meta-analysis. The overall analysis (N = 19) yielded a combined risk estimate for overweight/obesity of 1.19 (95% CI, 1.08-1.30) and the test of heterogeneity resulted into Q = 57.44 ( I2 = 68.67%, P ≤ .001). The risk of offspring obesity is 1.23 (95% CI, 1.09-1.39) and the test of heterogeneity resulted into Q = 39.55 ( I2 = 69.66%, P ≤ .001). Children born by cesarean section have an increased risk of obesity in adulthood.

Effects of vaginal seeding on gut microbiota, body mass index, and allergy risks in infants born through cesarean delivery: a randomized clinical trial

BACKGROUND

Vaginal seeding-exposure of neonates to maternal vaginal fluids-has been proposed to improve the microbiota of infants born through cesarean delivery, but its impacts on the infants' subsequent health outcomes remain unclear.

OBJECTIVE

This study aimed to examine the impacts of vaginal seeding on gut microbiota, growth, and allergy risks in infants born through cesarean delivery.

STUDY DESIGN

This randomized controlled trial was conducted at Liuyang Maternal and Child Health Care Hospital in Hunan, China. We estimated that a minimum sample size of 106 was needed by assuming a standardized effect size of 0.6 for the primary outcomes, with a statistical power of 80%, a 2-sided type I error of 0.05, and an expected loss to follow-up rate of 15%. Finally, 120 singleton term pregnant women scheduled for cesarean delivery were enrolled from November 2018 to September 2019. Infant follow-up was completed in September 2021. The participants were randomized in a 1:1 ratio to the vaginal seeding group (n=60; infants were swabbed immediately after birth using gauze preincubated in maternal vagina) or the control group (n=60; routine standard care). The first set of primary outcomes was infant body mass index and body mass index z-scores at 6, 12, 18, and 24 months of age. The other primary outcome was the total allergy risk score at 18 months for 20 common allergens (each scored from 0-6 points). Characteristics of gut microbiota, overweight/obesity, and allergic diseases and symptoms were included as secondary outcomes. The main analyses were performed according to the modified intention-to-treat principle.

RESULTS

Of 120 infants, 117 were included in the analyses. Infant body mass index and body mass index z-scores did not significantly differ between the 2 groups at any of the 4 time points, with the largest difference in point estimates occurring at 6 months: the mean (standard deviation) body mass index was 17.5 (1.4) kg/m² and 17.8 (1.8) kg/m² in the vaginal seeding and control groups, respectively (mean difference, -0.31 kg/m² [95% confidence interval, -0.91 to 0.28]; P=.30), and body mass index z-score was 0.2 (1.0) and 0.4 (1.1), respectively (mean difference, -0.20 [95% confidence interval, -0.58 to 0.18]; P=.31). The median total allergy risk score was 1.5 (interquartile range, 0.0-4.0) in the vaginal seeding group and 2.0 (interquartile range, 1.0-3.0) in the control group (median difference, 0.00 [95% confidence interval, -1.00 to 1.00]; P=.48). For infants from the vaginal seeding group, the relative abundance of genera Lactobacillus and Bacteroides in the gut microbiota was slightly yet nonsignificantly elevated at birth and 6 months, and the risk of overweight/obesity was lower at 6 months (0/57 vs 6/59; relative risk, 0.03 [95% confidence interval, 0.00-0.57]; P=.03) though not at subsequent time points. Other secondary outcomes did not differ between groups. No adverse events related to the intervention were reported.

CONCLUSION

For infants born through cesarean delivery, vaginal seeding has no significant impacts on the gut microbiota, growth, or allergy risks during the first 2 years of life.

Cesarean birth and risk of obesity from birth to adolescence: A cohort study

BACKGROUND

Recent studies have shown associations between cesarean birth and overweight. However, very few studies have evaluated weight gain or adiposity throughout life, and the majority are restricted to analysis during childhood. The purpose of this study was to analyze the effect of cesarean birth on obesity risk from birth to adolescence.

METHODS

The study sample was drawn from live births that occurred in 1999 and 2000 in Mato Grosso-Brazil. Participants were evaluated once when they were between 0 and 5 years of age and again after approximately 10 years (2009-2011). To measure the association between cesarean birth and obesity (Body Mass Index/age &gt;+2 z-scores), we used generalized estimation equations (GEE) with binomial distribution and log-binomial models for repeated measures, controlled by the following confounding factors: weight and length at birth, sex, gestational age, breastfeeding, maternal age and schooling, economic class in childhood, and maternal smoking during pregnancy. The exposure-time interaction term was evaluated to verify differences in the change in the risk of obesity over time.

RESULTS

56.8% of children in the sample were born by cesarean birth. Children born by cesarean had a higher risk of obesity from birth through adolescence (RR = 1.22, 95% CI = 1.02; 1.46), even after adjusting for covariates, when compared with those born vaginally. However, the time-exposure interaction term was not significant, which indicates that there was no increased risk of obesity over time.

CONCLUSION

Cesarean birth was positively associated with obesity from birth to adolescence, with a persistent risk in the period evaluated.

Disquiet concerning cesarean birth

Cesarean birth has increased substantially in many parts of the world over recent decades and concerns have been raised about the propriety of this change in obstetric practice. Sometimes, a cesarean is necessary to preserve fetal and maternal health. But in balancing the risks of surgical intervention the implicit assumption has been that cesarean birth is an equivalent alternative to vaginal birth from the standpoint of the immediate and long-term health of the fetus and neonate. Increasingly, we realize this is not necessarily so. Delivery mode per se may influence short-term and abiding problems with homeostasis in offspring, quite independent of the indications for the delivery and other potentially confounding factors. The probability of developing various disorders, including respiratory compromise, obesity, immune dysfunction, and neurobehavioral disorders has been shown in some studies to be higher among individuals born by cesarean. Moreover, many of these adverse effects are not confined to the neonatal period and may develop over many years. Although the associations between delivery mode and long-term health are persuasive, their pathogenesis and causality remain uncertain. Full exploration and a clear understanding of these relationships is of great importance to the health of offspring.

Beneficial Effects of Maternal Physical Activity during Pregnancy on Fetal, Newborn, and Child Health: Guidelines for Interventions during the Perinatal Period from the French National College of Midwives

The objective of this work is to synthesize current knowledge about the effects of maternal physical activity during pregnancy on children's health. During the prenatal and postnatal periods, maternal physical activity has protective effects against the risks of macrosomia, obesity, and other associated cardiometabolic disorders. Even though longitudinal studies in humans are still necessary to validate them, these effects have been consistently observed in animal studies. A remarkable effect of maternal physical activity is its positive role on neurogenesis, language development, memory, and other cognitive functions related to learning.

Estimating the effect of cesarean delivery on long-term childhood health across two countries

Assessing the impact of cesarean delivery (CD) on long-term childhood outcomes is challenging as conducting a randomized controlled trial is rarely feasible and inferring it from observational data may be confounded. Utilizing data from electronic health records of 737,904 births, we defined and emulated a target trial to estimate the effect of CD on predefined long-term pediatric outcomes. Causal effects were estimated using pooled logistic regression and standardized survival curves, leveraging data breadth to account for potential confounders. Diverse sensitivity analyses were performed including replication of results in an external validation set from the UK including 625,044 births. Children born in CD had an increased risk to develop asthma (10-year risk differences (95% CI) 0.64% (0.31, 0.98)), an average treatment effect of 0.10 (0.07-0.12) on body mass index (BMI) z-scores at age 5 years old and 0.92 (0.68-1.14) on the number of respiratory infection events until 5 years of age. A positive 10-year risk difference was also observed for atopy (10-year risk differences (95% CI) 0.74% (-0.06, 1.52)) and allergy 0.47% (-0.32, 1.28)). Increased risk for these outcomes was also observed in the UK cohort. Our findings add to a growing body of evidence on the long-term effects of CD on pediatric morbidity, may assist in the decision to perform CD when not medically indicated and paves the way to future research on the mechanisms underlying these effects and intervention strategies targeting them.

Developmental origins of adult diseases

The occurrence and mechanisms of developmental adult diseases have gradually attracted attention in recent years. Exposure of gametes and embryos to adverse environments, especially during plastic development, can alter the expression of certain tissue-specific genes, leading to increased susceptibility to certain diseases in adulthood, such as diabetes, cardiovascular disease, neuropsychiatric, and reproductive system diseases, etc. The occurrence of chronic disease in adulthood is partly due to genetic factors, and the remaining risk is partly due to environmental-dependent epigenetic information alteration, including DNA methylation, histone modifications, and noncoding RNAs. Changes in this epigenetic information potentially damage our health, which has also been supported by numerous epidemiological and animal studies in recent years. Environmental factors functionally affect embryo development through epimutation, transmitting diseases to offspring and even later generations. This review mainly elaborated on the concept of developmental origins of adult diseases, and revealed the epigenetic mechanisms underlying these events, discussed the theoretical basis for the prevention and treatment of related diseases.

Does a Healthy Lifestyle Lower the Elevated Risk of Obesity Caused by Caesarian Section Delivery in Children and Adolescents?

Background: Both caesarean section (CS) and lifestyle were linked with child adiposity. This study aimed to investigate whether CS delivery is linked with elevated risk of child adiposity regardless of a healthy lifestyle. Methods: All the subjects in this study came from a baseline survey of a national school-based program on healthy lifestyle interventions against adiposity among Chinese children and adolescents. A questionnaire was used to collect the information on delivery mode and lifestyle. According to the weighted lifestyle score, subjects were categorized into healthy, intermediate, and unhealthy lifestyle. Results: A total of 44,961 children aged 6−18 years were enrolled in the current study. Overall, 41.9% (18,855/44,961) of children were delivered by CS. Compared with children delivered by vaginal delivery, children delivered by CS had a higher adiposity risk (OR = 1.56; 95%CI: 1.46−1.66; p < 0.001) after adjustment for age, sex, region, mother adiposity, ethnicity, and weighted lifestyle factors. Compared with children with a healthy lifestyle, children with an unhealthy lifestyle had a higher risk of child adiposity (OR = 1.31; 95%CI: 1.19−1.44). Children delivered by CS who had an unhealthy lifestyle had a 106% higher (OR = 2.06; 95%CI: 1.79−2.37) risk of child adiposity compared with children delivered by vaginal delivery who had a healthy lifestyle. However, keeping a healthy lifestyle in later life seems not to offset the increased risk of child adiposity caused by CS (OR = 1.59; 95%CI: 1.39−1.82). Conclusions: Both CS and unhealthy lifestyle were linked with child adiposity risk. Keeping a healthy lifestyle did not counteract the elevated risk of child adiposity caused by CS.

Relationship between caesarean section delivery and risk of overweight/obesity among children aged 6–23 months in the Tamale Metropolis of Ghana

The recent exponential increase in caesarean section (CS) rates in many countries including Ghana requires an understanding of the potential long-term consequences on child health. The present study investigated the relationship between CS delivery and risk of childhood overweight/obesity. A retrospective cohort study was conducted from October 2019 to March 2020 in Ghana. Using multi-stage sampling, 553 mother–child pairs aged 6–23 months were selected from ten health facilities during child welfare clinic (CWC) services. We assessed the association between delivery mode (caesarean v. vaginal) and subsequent body mass index for age (BMI/age Z-score) using hierarchical multivariable linear regression analysis. The prevalence of overweight/obesity (BMI/age Z-score > +2 sd) in children was 3⋅6 %. After adjusting for maternal gestational weight gain, macrosomia and child feeding practices, children who were born through CS had mean BAZ which was 0⋅105 standard units significantly higher than their colleagues who were delivered through normal vaginal [beta coefficient (β) 0⋅105, (95 % CI 0⋅03, 0⋅55)]. CS birth was also associated with 3⋅2 times higher odds of overweight/obesity than vaginal delivery (AOR 3⋅23; 95 % CI 1⋅14, 9⋅13). Consequently, CS delivery was associated positively with increased body mass (adiposity) in the study sample. The association between CS delivery and risk of childhood obesity was attenuated after adjusting for macrosomia. These results would be important for informing clinicians and expectant mothers in considering CS delivery.

Has the cesarean epidemic in Czechia been reversed despite fertility postponement?

Background

Although the percentage of cesarean sections (CS) in Czechia is below the average of that of other developed countries (23.6%), it still exceeds WHO recommendations (15%). The first aim of the study is to examine the association between a CS birth and the main health factors and sociodemographic characteristics involved, while the second aim is to examine recent trends in the CS rate in Czechia. 

Methods

Anonymized data on all mothers in Czechia for 2018 taken from the National Register of Expectant Mothers was employed. The risk of cesarean delivery for the observed factors was tested via the construction of a binary logistic regression model that allowed for adjustments for all the other covariates in the model.

Results

Despite all the covariates being found to be statistically significant, it was determined that health factors represented a higher risk of a CS than sociodemographic characteristics. A previous CS was found to increase the risk of its recurrence by 33 times (OR = 32.96, 95% CI 30.95–35.11, p<0.001). The breech position increased the risk of CS by 31 times (OR = 31.03, 95% CI 28.14–34.29, p<0.001). A multiple pregnancy increased the odds of CS six-fold and the use of ART 1.8-fold. Mothers who suffered from diabetes before pregnancy were found to be twice as likely to give birth via CS (OR = 2.14, 95% CI 1.76–2.60, p<0.001), while mothers with gestational diabetes had just 23% higher odds of a CS birth (OR = 1.23, 95% CI 1.16–1.31, p<0.001). Mothers who suffered from hypertension gave birth via CS twice as often as did mothers without such complications (OR = 2.01, 95% CI 1.86–2.21, p<0.001).

Conclusions

The increasing age of mothers, a significant risk factor for a CS, was found to be independent of other health factors. Accordingly, delayed childbearing is thought to be associated with the increase in the CS rate in Czechia. However, since other factors come into play, further research is needed to assess whether the recent slight decline in the CS rate is not merely a temporal trend.

Differences in nutritional status between rural and urban Yucatec Maya children: The importance of early life conditions

Early‐life conditions shape childhood growth and are affected by urbanization and the nutritional transition. To investigate how early‐life conditions (across the “first” and “second” 1000 days) are associated with rural and urban children's nutritional status, we analyzed anthropometric data from Maya children in Yucatan, Mexico. We collected weight, height and triceps skinfold measures, then computed body mass and fat mass indices (BMI/FMI), in a cross‐sectional sample of 6‐year‐olds (urban n = 72, rural n = 66). Demographic, socioeconomic and early‐life variables (birthweight/mode, rural/urban residence, household crowding) were collected by maternal interview. We statistically analyzed rural‐urban differences in demographic, socioeconomic, early‐life, and anthropometric variables, then created linear mixed models to evaluate associations between early‐life variables and child anthropometric outcomes. Two‐way interactions were tested between early‐life variables and child sex, and between early‐life variables and rural‐urban residence. Results showed that rural children were shorter‐statured, with lower overweight/obesity and cesarean delivery rates, compared to urban children. Household crowding was a negative predictor of anthropometric outcomes; the strongest effect was in boys and in urban children. Birthweight positively predicted anthropometric outcomes, especially weight/BMI. Birth mode was positively (not statistically) associated with any anthropometric outcome. Cesarean delivery was more common in boys than in girls, and predicted increased height in urban boys. In conclusion, urbanization and household crowding were the most powerful predictors of Maya 6‐year‐old anthropometry. The negative effects of crowding may disproportionately affect Maya boys versus girls and urban versus rural children. Early‐life conditions shape Maya children's nutritional status both in the “first” and “second” 1000 days.

Association of Cesarean Delivery with Trajectories of Growth and Body Composition in Preschool Children

This study aimed to examine the association of cesarean delivery with trajectories of growth and body composition in preschool children. This ambidirectional cohort study was conducted between 2017 and 2020 in China. Information on the delivery mode, weight, and length/height of the children measured at routine healthcare visits was obtained from maternal and child health records. For three years while in kindergarten, children’s body mass index (BMI), fat mass index (FMI), fat-free mass index (FFMI), and percentage of body fat (FM%) were repeatedly measured. A BMI z score (zBMI) was calculated and standardized to WHO measures, and overweight and obesity were defined using the WHO reference. After adjustment for maternal age, maternal education, annual family income, prepregnancy BMI, gestational weight gain, gravidity, parity, gestational age, child sex, birthweight, breastfeeding duration, and the parent-reported dietary intake of the children, children born via cesarean delivery (n = 1992) versus those born vaginally (n = 1578) had higher zBMI growth rates beyond 36 months (β: 0.003; 95% CI: 0.001, 0.005 SD units/month) and elevated levels of FMI (β: 0.097; 95% CI: 0.026, 0.168 kg/m²), FM% (β: 0.402; 95% CI: 0.058, 0.745%) and zBMI (β: 0.073; 95% CI: 0.012, 0.133 units), but not FFMI (β: 0.022; 95% CI: −0.022, 0.066 kg/m²). The adjusted OR of overweight and obesity was 1.21 (95% CI: 1.04, 1.40). Cesarean delivery likely elevated zBMI growth rates and increased the risk of overweight and obesity in preschool children, with the elevation of fat mass but not fat-free mass.

Cesarean delivery on maternal request and common child health outcomes: A prospective cohort study in China

Background

Cesarean delivery vs vaginal delivery was reported to increase the risks of childhood obesity, pneumonia, anemia, and neurobehavioral disorders, but few studies were able to deal with the confounding biases associated with medical conditions indicating cesareans. This prospective cohort study aims to investigate the associations of non-medically indicated cesarean delivery on maternal request (CDMR) with these child health outcomes.

Methods

Among 17 748 liveborn infants whose mothers (primiparas) participated in a randomized controlled trial on micronutrient supplementation and pregnancy outcomes during 2006-2009 in 5 rural counties in Hebei Province, China, 6972 singletons born by full-term spontaneous vaginal delivery (SVD) and 3626 by CDMR were extracted for the assessments of obesity (weight-for-height z-score >3) and pneumonia (self-reported) at 1.5-5 years in 2011. Some children were further randomly selected from these two groups for the assessments of anemia (hemoglobin <110 g/L, 2341 SVD and 2417 CDMR) and neurobehavioral disorders (raw score of Child Behavior Checklist larger than the 90th percentile of the normative sample, 1257 SVD and 1060 CDMR).

Results

Compared with SVD, CDMR was associated with increased risks of obesity (adjusted odds ratio (aOR) = 1.41, 95% confidence interval (CI) = 1.14-1.75, P = 0.002) and anemia (aOR = 1.65, 95% CI = 1.28-2.12, P < 0.001), but not with the risk of pneumonia (aOR = 1.16, 95% CI = 0.94-1.45, P = 0.17) or neurobehavioral disorders (aORs varied from 0.82 to 0.91, P > 0.05) in childhood.

Conclusions

Cesarean delivery, independent of cesarean indications, is likely associated with childhood obesity and anemia, indicating a need to keep pregnant women informed, especially those seeking CDMR, a need to explore possible improvement on obstetric service, and even a need for main stakeholders to reach a compromise in making a cesarean decision.

Trial registration

ClinicalTrials.gov: NCT00133744 and NCT01404416

The association of cesarean section with overweight and neurodevelopment of Chinese children aged 1-5 months

OBJECTIVE

The purpose of this survey was to explore the association of delivery mode with overweight and neurodevelopment of Chinese infants aged 1-5 months.

MATERIALS AND METHODS

This study was based on a cross-sectional survey. Data for this study were obtained from the Children's Nutrition and Health System Survey in China which was conducted from 2019 to 2020. Characteristics of parents and children and the delivery mode were obtained using interview-administered questionnaires. Body mass index-for age z-score (BMI z) was calculated using World Health Organization (WHO) child growth standards. Children's neurodevelopment was assessed by a trained child health care physician using the Child Psychological Development Scale. The association of delivery mode with infant overweight was analyzed using a multivariable logistic regression model. We conducted a multivariable linear regression model to explore the relationship between delivery modes with neurodevelopment.

RESULTS

In total, the present analysis included 1,347 children aged 1-5 months, 35.61% were born via cesarean section, of which 15.21% were overweight. After adjustment for infant characteristics and parental factors, the cesarean section was significantly related with the likehood of being overweight [OR = 1.95; 95% confidence interval (CI): 1.27 to 2.98]. Children born via cesarean section had a 3.41-point decrease in gross motor development (β = -3.41; 95% CI: -5.77 to -1.05), a 3.65-point decrease in fine motor development (β = -3.65; 95% CI: -6.03 to -1.28), and a 2.96-point in language development (β = -2.96; 95% CI: -5.20 to -0.73), a 1.65-point in total development (β = -1.65; 95% CI: -3.17 to -0.14) compared with those who were vaginal birth.

CONCLUSION

In our study population, cesarean section was associated with overweight and neurodevelopment outcomes. The cesarean section might increase the likehood of infant overweight, and might decrease the developmental scores of gross motor, fine motor and language. Further studies should be conducted to verify the associations and explore the possible mechanisms.

Cesarean delivery and metabolic health and inflammation biomarkers during mid-childhood and early adolescence

BACKGROUND

We assessed differences in plasma levels of metabolic health and inflammation biomarkers during mid-childhood and early adolescence between children born by cesarean section vs. vaginal delivery.

METHODS

Mother-child pairs (N = 942) enrolled during pregnancy in obstetric practices and child follow-up started at birth. Risk biomarkers were assessed in blood samples collected at the mild-childhood (median = 7 years) and early adolescence (median = 13 years) in-person visits.

RESULTS

Two hundred and six children (22%) were born by cesarean section. There were no significant differences in biomarker levels between children born by cesarean and children born vaginally in mid-childhood. However, adolescents born by cesarean section had significantly lower adiponectin [% difference (95% confidence interval (CI)) = -11.3 (-18.1, -4.0) µg/mL] compared to vaginal delivery. We also found some suggestion of higher insulin resistance [insulin levels % difference (95% CI) = 11.5 (-0.40, 25.0) µU/mL and HOMA-IR (homeostatic model assessment of insulin resistance) % difference (95% CI) = 9.1 (-2.30, 21.8) U] in adolescents born by cesarean section compared to those born vaginally.

CONCLUSIONS

We found suggestive evidence that adolescents born by cesarean section show differences in certain metabolic health biomarkers relative to adolescents born by vaginal delivery. Further studies are needed to reevaluate these associations since the clinical significance of these differences is unclear.

IMPACT

Multiple studies show that children born by cesarean section are at higher risk of obesity compared to those born vaginally. It is unclear yet to what extent this elevated risk may extend to a more adverse profile of biomarkers of metabolic health and inflammation. Adolescents born by cesarean section show small differences in adiponectin and insulin relative to adolescents born by vaginal delivery. Adolescents born by cesarean section may be at higher risk to a more adverse profile of biomarkers of metabolic health and inflammation, but the clinical significance of these differences is uncertain.

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

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

Association of mode of delivery with offspring pubertal development in Project Viva: a prospective pre-birth cohort study in the USA

STUDY QUESTION

Is cesarean delivery associated with earlier offspring pubertal development?

SUMMARY ANSWER

We identified that boys born by cesarean delivery developed puberty earlier, evidenced by an earlier age at peak height velocity and earlier attainment of puberty score > 1, than boys born by vaginal delivery.

WHAT IS KNOWN ALREADY

Cesarean delivery is posited to have long-term effects on health outcomes. However, few studies have examined whether mode of delivery is related to pubertal development.

STUDY DESIGN, SIZE, DURATION

Prospective pre-birth cohort study consisting of 1485 mother-child pairs enrolled during pregnancy from obstetric practices and followed up until early adolescence (median age 12.9 years). Participant inclusion required data on mode of delivery and at least one measure of pubertal development.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Participants are children from the Project Viva study. We abstracted information on delivery mode from electronic medical records from children followed since birth (1999-2002) and examined the following markers of pubertal development: age at peak height velocity (APHV); age at menarche (girls only); parent-reported pubertal development score; and child-reported pictograph Tanner pubic hair staging. We used multivariable regression models to examine associations of delivery mode with these four pubertal indices, adjusting for the following confounders: demographic and socioeconomic factors; maternal height, pre-pregnancy BMI, total gestational weight gain, pregnancy conditions, parity, and maternal age at menarche; paternal height and BMI; gestational age at delivery and birthweight-for-gestational-age z-score.

MAIN RESULTS AND THE ROLE OF CHANCE

In this study, 23.2% of children were born by cesarean delivery. Girls had an earlier APHV, had a higher pubertal score throughout childhood and in early adolescence, and were more likely to attain puberty score >1 and Tanner pubic hair Stage >1 earlier compared to boys. Mean (SD) age at menarche in girls was 12.4 (1.0) years. Boys born by cesarean delivery had significantly earlier APHV (β -0.23 years; 95% CI -0.40, -0.05) and higher risk of earlier attainment of puberty score > 1 (hazard ratio 1.09; 95% CI 1.01, 1.19) than boys born by vaginal delivery, after adjusting for confounders. These associations were not mediated by pre-pubertal BMI and were similar for planned (no labor) and unplanned (labor) cesarean delivery. No associations were observed between delivery mode and time to attain Tanner pubic hair Stage > 1 in boys. In girls, mode of delivery was not associated with any of the measured pubertal development markers.

LIMITATIONS, REASONS FOR CAUTION

This study used, as secondary outcomes, parent- and child-reported measures of pubertal development, which may be more prone to error and misclassification than information collected by trained observers or physicians during clinical examinations. The findings may also not be generalizable to populations from different settings, because all participants lived in one geographic area, were well educated, and had health care.

WIDER IMPLICATIONS OF THE FINDINGS

Our findings provide support for cesarean delivery as a potential indicator of identifying children who are likely to experience earlier pubertal development; however, more studies are needed to confirm or refute these observations.

STUDY FUNDING/COMPETING INTEREST(S)

The project was funded by grants from the National Institutes of Health. The authors have no financial relationships or competing interests to disclose.

TRIAL REGISTRATION NUMBER

N/A.

A randomized, double blind, parallel, placebo-controlled study to investigate the efficacy of Lactobacillus paracasei N1115 in gut development of young children

In this clinical trial, the safety and effectiveness of Lactobacillus paracasei N1115 (LP N1115) were investigated as a potential probiotic to enhance gut development in young children born by caesarean section. Infants and young children between the ages of 6 months and 3 years were administered with a probiotic consisting of LP N1115 strain (n = 30) or placebo supplement (n = 30) over an 8 weeks intervention. And the stool consistency, bowel habits, salivary cortisol, fecal microbiota, and short-chain fatty acid metabolism were investigated. Efficacy data were obtained from 58 participants who completed the study. Overall, the placebo functioned similarly to LP N1115 group in relation to stool consistency, gastrointestinal symptoms, salivary cortisol, and short-chain fatty acids. However, the scoring data relating to the 6-18 months subgroup receiving LP N1115 remained stable over 8 weeks in comparison to placebo. Analysis of the fecal microbiota using 16S rRNA amplicon sequencing revealed that the phyla Firmicutes represented 62% of the microbial relative abundance in the feces of the subjects during the intervening period. No significant changes in alpha- or beta-diversity were noted between the placebo and LP N1115 groups overtime and at each time point. Differential abundance analysis indicated an increase in Lactobacillus in LP N1115 group at weeks 4 (p < .05) and 8 (p < .05) in comparison to the placebo group. These results suggest that probiotic supplementation with LP N1115 was well tolerated by the young children and subtle changes in the microbiome were noted throughout the intervention period.

From Short- to Long-Term Effects of C-Section Delivery on Microbiome Establishment and Host Health

The establishment of gut microbiota has been proven to be impacted by several factors during pregnancy, delivery, and neonate periods. The body of evidence describing C-section delivery (CSD) as one of the most disruptive events during early life has expanded in recent years, concluding that CSD results in a drastic change in microbiota establishment patterns. When comparing the gut microbiota composition of CSD babies with vaginally delivered (VD) babies, the former show a microbiome that closely resembles that found in the environment and the mother’s skin, while VD babies show a microbiome more similar to the vaginal microbiome. Although these alterations of normal gut microbiota establishment tend to disappear during the first months of life, they still affect host health in the mid–long term since CSD has been correlated with a higher risk of early life infections and non-transmissible diseases, such as inflammatory diseases, allergies, and metabolic diseases. In recent years, this phenomenon has also been studied in other mammals, shedding light on the mechanisms involved in the effects of a CSD on host health. In addition, strategies to revert the disruptions in gut microbiomes caused by a CSD are currently in the process of development and evaluation. In this review, we discuss the recent advances in CSD research, from the alteration of gut microbiota establishment to the possible effects on host health during early life and development.

Association of Mode of Obstetric Delivery With Child and Adolescent Body Composition

IMPORTANCE

Although the literature on the association between birth by cesarean delivery and children's anthropometry has continued to increase, only a few studies have examined the association of cesarean delivery with measures of body composition assessed using dual-energy x-ray absorptiometry (DXA), which allows the differentiation of fat and lean mass overall and in specific regions of the body.

OBJECTIVE

To investigate whether differences exist in DXA-measured body composition between children and adolescents born by cesarean delivery and those born by vaginal delivery.

DESIGN, SETTING, AND PARTICIPANTS

This prospective cohort study included singleton children of mothers enrolled between April 1999 and July 2002 in Project Viva, a longitudinal prebirth cohort of mother-child pairs in Massachusetts. The children had at least 1 DXA scan at a follow-up visit during middle childhood (2007-2010) and/or early adolescence (2013-2016). Data analysis was performed from October 16, 2020, to May 9, 2021.

EXPOSURES

Mode of delivery (cesarean vs vaginal).

MAIN OUTCOMES AND MEASURES

Total lean mass index, total and truncal fat mass indexes, visceral adipose tissue (VAT), subcutaneous abdominal adipose tissue, and total abdominal adipose tissue (TAAT) were estimated using DXA. Multivariable linear regression models were used to estimate the association between mode of delivery and DXA-derived outcomes with adjustment for confounders. Stabilized inverse probability weights were used to control for potential selection bias owing to loss to follow-up.

RESULTS

A total of 975 mother-child pairs were included in the study. The mean (SD) maternal age at study entry was 32.0 (5.5) years, and the mean (SD) self-reported prepregnancy body mass index (BMI; calculated as weight in kilograms divided by height in meters squared) was 25.0 (5.4). Of the children included in the study, 491 (50%) were female; 212 (22%) were born by cesarean delivery and 763 (78%) by vaginal delivery. Body composition in middle childhood as measured by DXA did not differ by mode of delivery. In early adolescence, participants born by cesarean delivery had a significantly greater total lean mass index (β, 0.4; 95% CI, 0.0-0.7), total fat mass index (β, 0.6; 95% CI, 0.1-1.1), truncal fat mass index (β, 0.3; 95% CI, 0.0-0.5), VAT area (β, 4.7; 95% CI, 0.9-8.6), and TAAT area (β, 23.8; 95% CI, 0.8-46.8) in a model adjusted for child sex and age at the time of DXA measurements; maternal age, educational level, race and ethnicity, total gestational weight gain, and smoking status during pregnancy; birth-weight-per-gestational-age z score; and paternal BMI. Associations between mode of delivery and measures of adiposity were found for cesarean deliveries performed in the absence of labor (total fat mass index: β, 1.3; 95% CI, 0.3-2.3; truncal fat mass index: β, 0.6; 95% CI, 0.1-1.0; VAT area: β, 10.7; 95% CI, 3.1-18.3; TAAT area: β, 47.3; 95% CI, 2.3-92.2). There were no associations after adjustment for maternal self-reported prepregnancy BMI (total lean mass index: β, 0.2; 95% CI, -0.1 to 0.6; total fat mass index: β, 0.4; 95% CI, -0.1 to 0.9; truncal fat mass index: β, 0.2; 95% CI, -0.1 to 0.4; VAT area: β, 3.0; 95% CI, -0.6 to 6.7; TAAT area: β, 13.6; 95% CI, -8.2 to 35.3).

CONCLUSIONS AND RELEVANCE

In this cohort study, adolescents born by cesarean delivery had significantly higher measures of lean mass, fat mass, and central adiposity compared with those born by vaginal delivery, but associations did not remain after adjustment for the mothers' self-reported prepregnancy BMI. The findings suggest that the association between birth by cesarean delivery and adolescent adiposity may partly be explained by maternal self-reported prepregnancy BMI.

C-section birth increases offspring obesity risk dependent on maternal diet and obesity status in rats

OBJECTIVE

The gut microbiota is a complex ecosystem that shapes host metabolism, especially in early life. Maternal vaginal and gut microbiota is vertically transmitted to offspring during natural birth. Offspring born by cesarean section (CS) do not receive these bacteria and exhibit higher obesity risk later in life. The objective of this study was to examine differences in obesity risk between offspring born naturally (NB) or by CS to lean/obese dams.

METHODS

Lean and obese rat dams gave birth to offspring naturally or by CS. Offspring obesity risk was analyzed via body weight/composition, food intake, sucrose preference, gut microbiota, and gene expression in gut and brain tissues.

RESULTS

Obese (O)+CS offspring showed greater weight gain and caloric intake but a reduction in hypothalamic agouti related neuropeptide, neuropeptide Y, and interleukin 1β expression compared with O+NB offspring. Lean (L)+CS offspring had higher serum corticosterone concentration and reduced liver peroxisome proliferator-activated receptor γ expression compared with L+NB. O+CS offspring had long-term alterations to gut microbiota, including increased relative abundance of Faecalibaculum and reduced Muribaculaceae.

CONCLUSIONS

Overall, CS alters obesity risk differentially based on maternal obesity status. Further studies looking at the risks of obesity associated with CS are needed, with special attention paid to maternal obesity status and gut microbiota.

An innovative postnatal risk assessment and corresponding care pathways in Preventive Child Healthcare

Aims

This study aims to evaluate the effectiveness of an innovative postnatal risk assessment (the postnatal Rotterdam Reproductive Risk Reduction checklist: R4U) and corresponding care pathways in Preventive Child Healthcare (PCHC), along with PCHC professional satisfaction.

Design

Four PCHC organizations located in three municipalities with a higher adverse perinatal outcome than the national average were selected for participation. The study concerns a historically controlled study design.

Methods

The study enrolled participants from September 2016 until December 2017. The historical cohort existed of children born in previous years from 2008 until 2016. The outcome measure was defined as catch‐up growth: more than 0.67 standard deviation score weight for height increase in the first 6 months of life. PCHC professional opinion was assessed with a digital survey.

Results

After the inclusion period, 1,953 children were included in the intervention cohort and 7,436 children in the historical cohort. Catch‐up growth was significantly less common in the intervention cohort; 14.9% versus 19.5% in the historical cohort (p < 0.001). A regression sensitivity analysis, using matching, showed an odds ratio of 0.957 (95% CI 0.938–0.976) for the intervention cohort. In the survey, 74 PCHC physicians and nurses participated; most of them were neutral concerning the benefits of the postnatal R4U.

Conclusion

This study shows that the implementation of a novel postnatal risk assessment including in PCHC is feasible and effective. Final efforts to ensure a widespread implementation should be taken.

Impact

PCHC offers a unique opportunity to recognize and address risk factors for growth and development in children and to implement care pathways. Effective and widely implemented risk assessments in antenatal and PCHC are scarce. To our knowledge, this kind of evidence‐based postnatal risk assessment has not been implemented in PCHC before and seizes the opportunity to prevent catch‐up growth and its long‐term effects.

Association of cesarean birth with prevalence of functional constipation in toddlers at 3 years of age: results from the Japan Environment and Children's Study (JECS)

BACKGROUND

The association between delivery mode and subsequent development of diseases is a growing area of research. Cesarean delivery affects the diversity of the microbiota in the infant gut, which may be associated with gastrointestinal disorders, including functional constipation, in infants. In this study, we investigated the association between delivery mode and prevalence of functional constipation in 3-year-old Japanese toddlers.

METHODS

This study used data from the Japan Environment and Children's Study, an ongoing nationwide birth cohort study. We analyzed 71,878 toddler-mother pairs. The presence of functional constipation was determined according to the Rome III diagnostic criteria. Odds ratios and 95% confidence intervals were calculated using logistic regression analysis.

RESULTS

The prevalence of functional constipation in 3-year-old Japanese toddlers was estimated to be 12.3%. Logistic regression analysis revealed that the prevalence of functional constipation was higher in toddlers born by cesarean delivery (13.1%) compared with those born by vaginal delivery (12.1%), independent of 22 confounders (adjusted odds ratios = 1.064, 95% confidence interval = 1.004-1.128).

CONCLUSIONS

We determined the prevalence of functional constipation in 3-year-old Japanese toddlers and found that delivery mode was associated with the prevalence of functional constipation in Japanese toddlers.

The Influence of Cesarean Section on the Composition and Development of Gut Microbiota During the First 3 Months of Life

The intestinal microbiota has emerged as a critical regulator of growth and development in the early postnatal period of life. Cesarean section (CS) delivery is one of the strongest disrupting factors of the normal colonization process and has been reported as a risk factor for disorders in later life. In this study, we dynamically and longitudinally evaluated the impact of CS on the initial colonization pattern and development of gut microbiota by 16 healthy Chinese infants with fecal samples collected at 9 time points (day 5, day 8, day 11, week 2, week 4, week 6, week 7, month 2, and month 3) during the first 3 months of life. The V3–V4 regions of 16S rRNA gene were analyzed by Illumina sequencing. In comparison with vaginally delivered (VD) infants, infants born by CS showed decreased relative abundance of Bacteroides and Parabacteroides and enrichment of Clostridium_sensu_stricto_1, Enterococcus, Klebsiella, Clostridioides, and Veillonella. Most interestingly, Firmicutes/Bacteroidetes ratio was found to be significantly higher in the CS group than in the VD group from day 5 until month 3. Besides, the results of microbial functions showed that the VD group harbored significantly higher levels of functional genes in vitamin B6 metabolism at day 5, day 8, week 2, week 4, week 6, week 7, month 2, and month 3 and taurine and hypotaurine metabolism at day 5, while the phosphotransferase system and starch and sucrose metabolism involved functional genes were plentiful in the CS group at day 11, week 2, week 4, week 6, week 7, and month 2 and at week 2, week 7, and month 2, respectively. Our results establish a new evidence that CS affected the composition and development of gut microbiota in the first 3 months and provide a novel insight into strategies for CS-related disorders in later life.

Early Risk Factors for Obesity in the First 1000 Days-Relationship with Body Fat and BMI at 2 Years

(1) Background: Obesity is defined as an excessive accumulation of body fat. Several early developmental factors have been identified which are associated with an increased risk of childhood obesity and increased adiposity in childhood. The primary objective of the present study is to analyse the effect of various early risk factors on Body Mass Index (BMI) and body fat percentage at 2 years of age. (2) Methods: A prospective cohort study design was used, with the sample consisting of 109 mother-child pairs from whom data were collected between early pregnancy and 2 years old. Adiposity was determined based on skinfold measurements using the Brooks and Siri formulae. Mean comparison tests (Student's t-test and ANOVAs) and multiple linear regression models were used to analyse the relationship between early programming factors and dependent variables. (3) Results: Maternal excess weight during early pregnancy (β = 0.203, p = 0.026), gestational smoking (β = 0.192, p = 0.036), and accelerated weight gain in the first 2 years (β = - 0.269, p = 0.004) were significantly associated with high body fat percentage. Pre-pregnancy BMI and accelerated weight gain in the first 2 years were associated with high BMI z-score (β = 0.174, p = 0.047 and β = 0.417, p = 0.000 respectively). The cumulative effect of these variables resulted in high values compared to the baseline zero-factor group, with significant differences in BMI z-score (F = 8.640, p = 0.000) and body fat percentage (F = 5.402, p = 0.002) when three factors were present. (4) Conclusions: The presence of several early risk factors related to obesity in infancy was significantly associated with higher BMI z-score and body fat percentage at 2 years of age. The presence of more than one of these variables was also associated with higher adiposity at 2 years of age. Early prevention strategies should address as many of these factors as possible.

Associations of caesarean section with body mass and waist circumference trajectories from age 2 to 13 years: A nationally representative birth cohort study in Australia

BACKGROUND

Measuring obesity at a single time point does not explain the independent association between C-section birth and obesity in a child's life course.

OBJECTIVES

This study aimed to explore the longitudinal link between C-section with obesity trajectories during childhood.

METHODS

We analysed data from a nationally representative birth cohort study named "Longitudinal Study of Australian Children (LSAC)", commenced in 2004. General obesity was measured through the Body Mass Index (BMI) and abdominal obesity by the Waist Circumference (WC) using the biennially collected data from age 2 to 13 years (2006-2016). Group-based trajectory modelling was applied to identify the distinct pattern of BMI & WC trajectories. Multivariable multinomial logistic regression models were used to assess the association between C-section and obesity trajectories after adjusting for perinatal factors.

RESULTS

Of the 3524 study children, 30% were born by C-section. Three distinct BMI trajectory groups emerged: stable normal (60%), moderately rising (33%) and accelerated (7%). The WC trajectories were, stable normal (58%), moderate (34%) and accelerated (8%). Compared with the stable normal group, children born through C-section had a higher risk to follow accelerated trajectories for both BMI (OR:1.72; 95% CI: 1.28-2.32) and WC (OR: 1.51; 95% CI: 1.15-1.98) with P-value <0.01. Adjustment of potential confounders did not alter these associations substantially.

CONCLUSIONS

C-section birth significantly increases the risk of having an accelerated obesity trajectory in children. Limiting the C-section for absolute clinical causes and early institution of preventive approach can reduce the obesity burden among children delivered through C-section.

Oral administration of maternal vaginal microbes at birth to restore gut microbiome development in infants born by caesarean section: A pilot randomised placebo-controlled trial

BACKGROUND

Birth by caesarean section (CS) is associated with aberrant gut microbiome development and greater disease susceptibility later in life. We investigated whether oral administration of maternal vaginal microbiota to infants born by CS could restore their gut microbiome development in a pilot single-blinded, randomised placebo-controlled trial (Australian New Zealand Clinical Trials Registry, ACTRN12618000339257).

METHODS

Pregnant women scheduled for a CS underwent comprehensive antenatal pathogen screening. At birth, healthy neonates were randomised to receive a 3 ml solution of either maternal vaginal microbes (CS-seeded, n = 12) or sterile water (CS-placebo, n = 13). Vaginally-born neonates were used as the reference control (VB, n = 22). Clinical assessments occurred within the first 2 h of birth, and at 1 month and 3 months of age. Infant stool samples and maternal vaginal extracts from CS women underwent shotgun metagenomic sequencing. The primary outcome was gut microbiome composition at 1 month of age. Secondary outcomes included maternal strain engraftment, functional potential of the gut microbiome, anthropometry, body composition, and adverse events.

FINDINGS

Despite the presence of viable microbial cells within transplant solutions, there were no observed differences in gut microbiome composition or functional potential between CS-seeded and CS-placebo infants at 1 month or 3 months of age. Both CS groups displayed the characteristic signature of low Bacteroides abundance, which contributed to a number of biosynthesis pathways being underrepresented when compared with VB microbiomes. Maternal vaginal strain engraftment was rare. Vaginal seeding had no observed effects on anthropometry or body composition. There were no serious adverse events associated with treatment.

INTERPRETATION

Our pilot findings question the value of vaginal seeding given that oral administration of maternal vaginal microbiota did not alter early gut microbiome development in CS-born infants. The limited colonisation of maternal vaginal strains suggest that other maternal sources, such as the perianal area, may play a larger role in seeding the neonatal gut microbiome.

FUNDING

Health Research Council of New Zealand, A Better Start - National Science Challenge.

Neonatal Immune System Ontogeny: The Role of Maternal Microbiota and Associated Factors. How Might the Non-Human Primate Model Enlighten the Path?

Interactions between the immune system and the microbiome play a crucial role on the human health. These interactions start in the prenatal period and are critical for the maturation of the immune system in newborns and infants. Several factors influence the composition of the infant's microbiota and subsequently the development of the immune system. They include maternal infection, antibiotic treatment, environmental exposure, mode of delivery, breastfeeding, and food introduction. In this review, we focus on the ontogeny of the immune system and its association to microbial colonization from conception to food diversification. In this context, we give an overview of the mother-fetus interactions during pregnancy, the impact of the time of birth and the mode of delivery, the neonate gastrointestinal colonization and the role of breastfeeding, weaning, and food diversification. We further review the impact of the vaccination on the infant's microbiota and the reciprocal case. Finally, we discuss several potential therapeutic interventions that might help to improve the newborn and infant's health and their responses to vaccination. Throughout the review, we underline the main scientific questions that are left to be answered and how the non-human primate model could help enlighten the path.

Association between mode of delivery and body mass index at 4-5 years in White British and Pakistani children: the Born in Bradford birth cohort

BACKGROUND

Globally, it is becoming more common for pregnant women to deliver by caesarean section (CS). In 2020, 31% of births in England were CS, surpassing the recommended prevalence of CS. Concerns have been raised regarding potential unknown consequences of this mode of delivery. Childhood adiposity is also an increasing concern. Previous research provides inconsistent conclusions on the association between CS and childhood adiposity. More studies are needed to investigate the consequences of CS in different populations and ethnicities. Therefore, this study investigates the association between mode of delivery and BMI, in children of 4-5 years and if this differs between White British (WB) and Pakistani ethnicities, in Bradford UK.

METHODS

Data were obtained from the Born in Bradford (BiB) cohort, which recruited pregnant women at the Bradford Royal Infirmary, between 2007 and 2010. For these analyses, a sub-sample (n = 6410) of the BiB cohort (n = 13,858) was used. Linear regression models determined the association between mode of delivery (vaginal or CS) and BMI z-scores at 4-5 years. Children were categorised as underweight/healthy weight, overweight and obese, and logistic regression models determined the odds of adiposity. Effect modification by ethnicity was also explored.

RESULTS

Multivariable analysis found no evidence for a difference in BMI z-score between children of CS and vaginal delivery (0.005 kg/m², 95% CI = - 0.062-0.072, p = 0.88). Neither was there evidence of CS affecting the odds of being overweight (OR = 1.05, 95% CI = 0.86-1.28, p = 0.65), or obese (OR = 0.98, 95% CI = 0.74-1.29, p = 0.87). There was no evidence that ethnicity was an effect modifier of these associations (p = 0.97).

CONCLUSION

Having CS, compared to a vaginal delivery, was not associated with greater adiposity in children of 4-5 years in this population. Concerns over CS increasing adiposity in children are not supported by the findings reported here using the BiB study population, of both WB and Pakistani families.

Are there adverse outcomes for child health and development following caesarean section delivery? Can we justify using elective caesarean section to prevent obstetric pelvic floor damage?

INTRODUCTION AND HYPOTHESIS

Elective pre-labour Caesarean section (CS) delivery is widely regarded as the panacea for all pelvic floor dysfunction despite substantial epidemiological evidence that it is only partially protective. To demand a CS is also considered a right for the well-counselled patient, even without an elevated risk of incontinence or prolapse. In recent years there has been increasing data on possible adverse health outcomes for children delivered by CS over those delivered vaginally. This includes respiratory illness, atopic conditions, obesity, diabetes and other severe auto-immune diseases. Concern has also been raised over possible impacts on cognitive and neuropsychological development in these children. Often the response has been to dismiss these outcomes as a result of the indication for the CS birth such as antenatal compromise or maternal disease. However the marked increase in non-medical Caesarean delivery throughout many regions of the world has allowed us to better distinguish these contributing factors.

METHODS

This narrative review looks at some of the more recent evidence on adverse health and developmental outcomes associated with CS, particularly pre-labour CS and the implications for the long term health of our society.

RESULTS

Epidemiological studies and animal research indicate an increased risk of negative impacts on child physical health and neuro-cognitive development aftercaesarean section delivery, particularly pre-labour Caesarean section, compared with vaginal delivery. This elevated risk persists after correction forobstetric and maternal factors.

CONCLUSION

Caesarean section delivery can result in adverse outcomes for infant, maternal and societal wellbeing. Elective Caesarean section, purely to potentially minimise pelvic floor dysfunction, cannot be justified.

Global Changes of 5-mC/5h-mC Ratio and Methylation of Adiponectin and Leptin Gene in Placenta Depending on Mode of Delivery

It was suggested that the epigenetic alterations of the placenta are associated with obesity, as well as the delivery mode. This study aimed to assess the effect of maternal outcome and delivery procedure on global placental DNA methylation status, as well as selected 5'-Cytosine-phosphate-Guanine-3' (CpG) sites in ADIPOQ and LEP genes. Global DNA methylation profile in the placenta was assessed using the 5-methylcytosine (5-mC) and 5-hydroxymethylcytosine (5-hmC) ratio evaluated with the ELISA, followed by target gene methylation patterns at selected gene regions which were determined using methylation-specific qPCR in 70 placentas from healthy, pregnant women with single pregnancy. We found no statistically significant differences in 5-mC/5-hmC ratio between intrapartum cesarean sections (CS) and vaginal deliveries (p = 0.214), as well as between elective cesarean sections and vaginal deliveries (p = 0.221). In intrapartum cesarean sections, the ADIPOQ demethylation index was significantly higher (the average: 1.75) compared to elective cesarean section (the average: 1.23, p = 0.010) and vaginal deliveries (the average: 1.23, p = 0.011). The LEP demethylation index did not significantly differ among elective CS, intrapartum CS, and vaginal delivery groups. The demethylation index of ADIPOQ correlated negatively with LEP in the placenta in the vaginal delivery group (r = -0.456, p = 0.017), but not with the global methylation. The methylation of a singular locus might be different depending on the mode of delivery and uterine contractions. Further studies should be conducted with locus-specific analysis of the whole genome to detect the methylation index of specific genes involved in metabolism.

A good start in life is important-perinatal factors dictate early microbiota development and longer term maturation

Maternal health status is vital for the development of the offspring of humans, including physiological health and psychological functions. The complex and diverse microbial ecosystem residing within humans contributes critically to these intergenerational impacts. Perinatal factors, including maternal nutrition, antibiotic use and maternal stress, alter the maternal gut microbiota during pregnancy, which can be transmitted to the offspring. In addition, gestational age at birth and mode of delivery are indicated frequently to modulate the acquisition and development of gut microbiota in early life. The early-life gut microbiota engages in a range of host biological processes, particularly immunity, cognitive neurodevelopment and metabolism. The perturbed early-life gut microbiota increases the risk for disease in early and later life, highlighting the importance of understanding relationships of perinatal factors with early-life microbial composition and functions. In this review, we present an overview of the crucial perinatal factors and summarise updated knowledge of early-life microbiota, as well as how the perinatal factors shape gut microbiota in short and long terms. We further discuss the clinical consequences of perturbations of early-life gut microbiota and potential therapeutic interventions with probiotics/live biotherapeutics.

The Pediatric Obesity Microbiome and Metabolism Study (POMMS): Methods, Baseline Data, and Early Insights

OBJECTIVE

The purpose of this study was to establish a biorepository of clinical, metabolomic, and microbiome samples from adolescents with obesity as they undergo lifestyle modification.

METHODS

A total of 223 adolescents aged 10 to 18 years with BMI ≥95th percentile were enrolled, along with 71 healthy weight participants. Clinical data, fasting serum, and fecal samples were collected at repeated intervals over 6 months. Herein, the study design, data collection methods, and interim analysis-including targeted serum metabolite measurements and fecal 16S ribosomal RNA gene amplicon sequencing among adolescents with obesity (n = 27) and healthy weight controls (n = 27)-are presented.

RESULTS

Adolescents with obesity have higher serum alanine aminotransferase, C-reactive protein, and glycated hemoglobin, and they have lower high-density lipoprotein cholesterol when compared with healthy weight controls. Metabolomics revealed differences in branched-chain amino acid-related metabolites. Also observed was a differential abundance of specific microbial taxa and lower species diversity among adolescents with obesity when compared with the healthy weight group.

CONCLUSIONS

The Pediatric Metabolism and Microbiome Study (POMMS) biorepository is available as a shared resource. Early findings suggest evidence of a metabolic signature of obesity unique to adolescents, along with confirmation of previously reported findings that describe metabolic and microbiome markers of obesity.

Obesity, Early Life Gut Microbiota, and Antibiotics

Obesity is a major public health problem that continues to be one of the leading risk factors for premature death. Early life is a critical period of time when the gut microbiota and host metabolism are developing in tandem and significantly contribute to long-term health outcomes. Dysbiosis of the gut microbiota, particularly in early life, can have detrimental effects on host health and increase the susceptibility of developing obesity later in life. Antibiotics are an essential lifesaving treatment; however, their use in early life may not be without risk. Antibiotics are a leading cause of intestinal dysbiosis, and early life administration is associated with obesity risk. The following review explores the relevant literature that simultaneously examines antibiotic-induced dysbiosis and obesity risk. Current evidence suggests that disruptions to the composition and maturation of the gut microbiota caused by antibiotic use in early life are a key mechanism linking the association between antibiotics and obesity. Without compromising clinical practice, increased consideration of the long-term adverse effects of antibiotic treatment on host health, particularly when used in early life is warranted. Novel adjunct interventions should be investigated (e.g., prebiotics) to help mitigate metabolic risk when antibiotic treatment is clinically necessary.

Crosstalk between sIgA-Coated Bacteria in Infant Gut and Early-Life Health

Gut microbiota transmission from mother to offspring has attracted much interest in recent years. The gut microbiota in the infant plays a potentially significant role in modulating and maintaining the development of infant immunity. Secretory immunoglobulin A (sIgA), the major immunoglobulin in the intestine, can target polysaccharides and flagellin on the bacterial surface, resulting in sIgA-coated bacteria. The presentation of specific bacteria coated with sIgA may be a signal of disease and provide novel insights into the relationship between infant microbiota and disease. Here, we review the composition of sIgA-coated bacteria in the adult intestine, human milk, and the infant intestine, as well as the factors that influence the development of gut microbiota in early life. Then, we highlight the diseases that are related to variations in sIgA-coated bacteria in the infant and adult intestine. Furthermore, we discuss the possibility that sIgA-coated bacteria could play a role in mediating both innate and adaptive immune responses. Finally, we propose directions for future research to promote our understanding within this field.