Cesarean delivery is associated with celiac disease but not inflammatory bowel disease in children

Pathophysiology of celiac disease

Celiac disease results from the interplay of genetic, environmental, and immunologic factors. An understanding of the pathophysiology of celiac disease, in which the trigger (wheat, rye, and barley) is known, will undoubtedly reveal basic mechanisms that underlie other autoimmune diseases (eg, type 1 diabetes) that share many common pathogenic perturbations. This review describes seminal findings in each of the 3 domains of the pathogenesis of celiac disease, namely genetics, environmental triggers, and immune dysregulation, with a focus on newer areas of investigation such as non-HLA genetic variants, the intestinal microbiome, and the role of the innate immune system.

Systematic review: early infant feeding and the prevention of coeliac disease

BACKGROUND

PREVENTCD, Prevent Coeliac Disease, is an international project investigating the hypothesis of possible induction of tolerance to gluten in genetically predisposed children through introducing small quantities of gluten during the period of breastfeeding.

AIM

To summarise current knowledge on the possible relationship between early feeding practices and the risk of coeliac disease (CD).

METHODS

The Cochrane Library, MEDLINE, and EMBASE databases were searched in May 2011, and the search was updated in January 2012, and again in July 2012.

RESULTS

Breastfeeding (BF) and CD: some studies show a protective effect of BF, while others show no effect. No studies have shown a long-term preventive effect. BF at the time of gluten introduction and CD: Results from a meta-analysis of five observational case-control studies suggest that BF at gluten introduction is associated with a lower risk of CD compared with formula feeding. It is unclear whether BF provides a permanent protection or only delays the onset of CD. Timing of gluten introduction: The data suggest that both early (≤4 months) and late (≥7 months) introduction of gluten may increase the risk of CD. Amount of gluten at weaning (and later) and CD: One incident case-referent study documented that the introduction of gluten in large amounts compared with small or medium amounts increased the risk of CD.

CONCLUSIONS

In the absence of clear evidence, in order to decrease the risk of later coeliac disease, it is reasonable to avoid both early (<4 months) and late (≥7 months) introduction of gluten, and to introduce gluten while the infant is still being breastfed. Future studies may clarify the remaining uncertainties.

The human milk microbiome changes over lactation and is shaped by maternal weight and mode of delivery

BACKGROUND

Breast milk is recognized as the most important postpartum element in metabolic and immunologic programming of health of neonates. The factors influencing the milk microbiome and the potential impact of microbes on infant health have not yet been uncovered.

OBJECTIVE

Our objective was to identify pre- and postnatal factors that can potentially influence the bacterial communities inhabiting human milk.

DESIGN

We characterized the milk microbial community at 3 different time points by pyrosequencing and quantitative polymerase chain reaction in mothers (n = 18) who varied in BMI, weight gain, and mode of delivery.

RESULTS

We found that the human milk microbiome changes over lactation. Weisella, Leuconostoc, Staphylococcus, Streptococcus, and Lactococcus were predominant in colostrum samples, whereas in 1- and 6-mo milk samples the typical inhabitants of the oral cavity (eg, Veillonella, Leptotrichia, and Prevotella) increased significantly. Milk from obese mothers tended to contain a different and less diverse bacterial community compared with milk from normal-weight mothers. Milk samples from elective but not from nonelective mothers who underwent cesarean delivery contained a different bacterial community than did milk samples from individuals giving birth by vaginal delivery, suggesting that it is not the operation per se but rather the absence of physiological stress or hormonal signals that could influence the microbial transmission process to milk.

CONCLUSIONS

Our results indicate that milk bacteria are not contaminants and suggest that the milk microbiome is influenced by several factors that significantly skew its composition. Because bacteria present in breast milk are among the very first microbes entering the human body, our data emphasize the necessity to understand the biological role that the milk microbiome could potentially play for human health.

The role of intestinal alkaline phosphatase in pediatric inflammatory bowel and celiac diseases

Intestinal alkaline phosphatase enzyme plays a pivotal role in the maintenance of intestinal mucosal barrier integrity with the detoxification capacity of lipopolysaccharide, the ligand of Toll-like receptor 4. The inappropriate immune responses and the damage of the mucosal barrier may contribute to the initiation of inflammatory bowel and celiac diseases. In the inflamed colonic mucosa of children with inflammatory bowel disease and in the duodenal mucosa of newly diagnosed children with celiac disease, the decreased intestinal alkaline phosphatase and increased Toll-like receptor 4 protein expression may generate enhanced lipopolysaccharide activity, which may strengthen tissue damaging processes. The enhancement of intestinal alkaline phosphatase activity in an animal model of colitis and in therapy resistant, adult patients with ulcerative colitis reduced the symptoms of intestinal inflammation. In accordance with these results, the targeted intestinal administration of the enzyme in the two examined disorders may be a supplemental therapeutic option in the future. Orv. Hetil., 2012, 153, 1389–1395.

Prenatal and perinatal characteristics associated with pediatric-onset inflammatory bowel disease

BACKGROUND

The majority of studies that report early life risk factors for pediatric-onset inflammatory bowel disease (IBD) do not account for potential confounding, which can lead to spurious associations and incorrect inferences.

AIMS

To assess the relationship between prenatal and perinatal characteristics and the risk of pediatric-onset IBD accounting for potential confounding.

METHODS

We conducted a nested case-control study of 189 cases aged ≤18 years and 3,080 age- and membership-matched controls born at a Kaiser Permanente Northern California facility between 1984 and 2006. The cases were diagnosed with IBD between 1996 and 2006 and diagnosis was confirmed by chart review. We obtained prenatal and perinatal characteristics from the electronic clinical records of the mother and child. Conditional logistic regression was used to assess the associations between these factors and risk of incident IBD, Crohn's disease, and ulcerative colitis.

RESULTS

In analyses accounting for confounding, maternal IBD (odds ratio [OR] 5.1, 95 % confidence interval [CI] 2.0-12.9) and white race (OR 2.3, 95 % CI 1.6-3.2) were the only factors statistically associated with pediatric-onset IBD. Maternal respiratory infection during pregnancy (OR 2.0, 95 % CI 1.0-4.0), age < 20 years (OR 2.0, 95 % CI 0.8-4.7) and gestational hypertension (OR 1.7, 95 % CI 1.0-2.7) were associated with pediatric-onset IBD, but did not achieve statistical significance.

CONCLUSIONS

Maternal history of IBD and race were the only characteristics of those that we examined that were associated with the development of pediatric IBD in this well-documented population of cases and matched controls.

Microbial ecology and host-microbiota interactions during early life stages

The role of human microbiota has been redefined during recent years and its physiological role is now much more important than earlier understood. Intestinal microbial colonization is essential for the maturation of immune system and for the developmental regulation of the intestinal physiology. Alterations in this process of colonization have been shown to predispose and increase the risk to disease later in life. The first contact of neonates with microbes is provided by the maternal microbiota. Moreover, mode of delivery, type of infant feeding and other perinatal factors can influence the establishment of the infant microbiota. Taken into consideration all the available information it could be concluded that the exposure to the adequate microbes early in gestation and neonatal period seems to have a relevant role in health. Maternal microbial environment affects maternal and fetal immune physiology and, of relevance, this interaction with microbes at the fetal-maternal interface could be modulated by specific microbes administered to the pregnant mother. Indeed, probiotic interventions aiming to reduce the risk of immune-mediated diseases may appear effective during early life.

Development of healthy gut microbiota early in life

A healthy intestinal microbiota profile in early life is related to health later in life. An aberrant composition is associated with risks of systemic problems, such as obesity, diabetes and allergic diseases, including asthma and enteric inflammatory conditions, sometimes manifesting at 7 years of age. A healthy and balanced gut microbiota profile in infancy, especially with regard to bifidobacteria, is directly related to mode of delivery (natural birth) and quality of breast milk, which in turn is affected by the mother's own systemic health and nutritional status. Pregnant women of normal body weight and healthy microbiota profiles, both gut microbiota and breast milk microbiota, have greater opportunities to pass on compounds, antigens modified by the mother's gut and other agents that promote the development of a healthy immune system in the breastfed infant.

Expression of microbiota, Toll-like receptors, and their regulators in the small intestinal mucosa in celiac disease

OBJECTIVES

Less than one-tenth of the carriers of the risk genes HLA-DQ2 or HLA-DQ8 develop celiac disease, suggesting that other genetic and environmental factors are important in the pathogenesis. The role of gut microbiota has been addressed previously with inconsistent findings. Our aim was to evaluate microbiota, its receptors (Toll-like receptors [TLRs]), and regulators of the TLRs in the small intestinal mucosa in celiac disease.

METHODS

Microbiota was analyzed by quantitative polymerase chain reaction (total bacteria and 10 bacterial group- and species-specific primers) and gene expression of interleukin-8 (IL-8), TLR2, TLR3, TLR4, TLR5, TLR9, and regulators of TLRs, Toll-interacting protein (TOLLIP), and single immunoglobulin IL-1R-related molecule, by relative quantitative reverse transcription-polymerase chain reaction in 10 children with celiac disease (untreated celiacs), 9 children with normal small intestinal mucosa (controls), and 6 adults with celiac disease with normal small intestinal mucosa after following a gluten-free diet (treated celiacs).

RESULTS

Small intestinal microbiota was comparable among controls, untreated celiacs, and treated celiacs. Expression of IL-8 mRNA, a marker of intestinal inflammation, was significantly increased in untreated celiacs as compared with treated celiacs (P=0.002) and controls (P=0.001). Expression of TLR-2 mRNA was significantly decreased in untreated (P=0.001) and treated (P=0.03) celiacs, whereas expression of TLR-9 mRNA was increased in untreated celiacs (P=0.001) as compared with controls. Expression of TOLLIP mRNA was downregulated in untreated celiacs as compared with controls (P=0.02).

CONCLUSIONS

Altered gene expression of TLR2, TLR9, and TOLLIP in small intestinal biopsies in celiac disease suggests that microbiota-associated factors may be important in the development of the disease.

Cesarean section and offspring's risk of inflammatory bowel disease: a national cohort study

BACKGROUND

Intestinal bacteria have been implicated in the etiology of the common inflammatory bowel diseases (IBD) ulcerative colitis and Crohn's disease. Because delivery by cesarean section disturbs the normal bacterial colonization of the newborn's intestine, we determined the risk of IBD according to mode of delivery.

METHODS

A register-based national cohort study of 2.1 million Danes born 1973-2008. The effect of mode of delivery on IBD incidence in the age-span 0-35 years was estimated by means of confounder-adjusted incidence rate ratios (IRRs) with 95% confidence intervals (CIs) obtained in Poisson regression analysis. Information on mode of delivery was obtained from the Danish Medical Birth Registry and cases of IBD were identified in the Danish National Patient Registry 1977-2008.

RESULTS

During 32.6 million person-years of follow-up, a total of 8142 persons were diagnosed with IBD before age 36 years. Cesarean section was associated with moderately, yet significantly, increased risk of IBD at age 0-14 years (IRR 1.29, 95% CI 1.11-1.49), regardless of parental disposition to IBD. Assuming causality, an estimated 3.2% of IBD cases before age 15 years were attributable to cesarean section.

CONCLUSIONS

Rates of IBD with onset in childhood are moderately increased after birth by cesarean section but underlying mechanisms remain unclear. Even if the association is causal, the possible impact of increasing cesarean section practices on the overall burden of IBD in childhood is small.

Timing of introduction of gluten and celiac disease risk

Breast milk is the natural nutrition for infants, but in the second half of the first year of life, complementary feeding is needed. Many complementary foods contain gluten, but gluten exposure is associated with the risk of developing celiac disease (CD). CD is a disease with considerable morbidity and mortality. Although CD is associated with certain genetic features, carrying the human leukocyte antigen haplotypes DQ2 or DQ8 (a prerequisite for CD development) cannot fully explain who will or who will not develop CD. Potential risk factors for CD include perinatal events and infant feeding practice. With the exception that children who are breastfed at and beyond gluten introduction into the diet probably may be at a lower risk of developing CD, and that heavy gluten load early in life may increase the risk of future CD, data on the impact of infant feeding are inconsistent.

Cesarean section and the risk of pediatric Crohn's disease

BACKGROUND

Crohn's disease (CD) could involve an inappropriate immune response against normal bowel flora. Disrupted or atypical patterns of microbial bowel colonization may impair development of homeostasis between gut flora and the immune system. Perinatal microbial exposures may be particularly important in stimulating intestinal immune recognition. As birth by cesarean section is thought to represent an atypical pattern of early bowel colonization, we examined its association with pediatric CD.

METHODS

Some 1536 patients diagnosed with pediatric CD and 15,439 controls matched by delivery unit, week of birth, sex, and born between 1973 and 2006 were identified through Swedish registers. The association of birth by cesarean section with pediatric CD was examined using conditional logistic regression, with stratification by sex and adjustment for parental socioeconomic index and maternal infections during pregnancy.

RESULTS

Birth by cesarean section is associated with a modestly increased risk for pediatric CD among boys (odds ratio [OR] = 1.25, 95% confidence interval [CI] 1.01-1.54) but not girls, (OR = 0.99, 95% CI 0.76-1.29) and elective cesarean section is associated with a modest increased risk for the entire population (OR = 1.36, 95% CI 1.02-1.80).

CONCLUSIONS

This study does not suggest that the delivery procedure should be altered, but the findings may be of etiological significance in CD, indicating a potential role for perinatal exposures associated with delivery mode. Although the sex difference may have arisen by chance, the modestly increased CD risk for boys delivered by cesarean section is consistent with sex-specific differences in susceptibility to some exposures.

Cesarean section and risk of obesity in childhood, adolescence, and early adulthood: evidence from 3 Brazilian birth cohorts

BACKGROUND

The number of cesarean sections (CSs) is increasing in many countries, and there are concerns about their short- and long-term effects. A recent Brazilian study showed a 58% higher prevalence of obesity in young adults born by CS than in young adults born vaginally. Because CS-born individuals do not make contact at birth with maternal vaginal and intestinal bacteria, the authors proposed that this could lead to long-term changes in the gut microbiota that could contribute to obesity.

OBJECTIVE

We assessed whether CS births lead to increased obesity during childhood, adolescence, and early adulthood in 3 birth cohorts.

DESIGN

We analyzed data from 3 birth-cohort studies started in 1982, 1993, and 2004 in Southern Brazil. Subjects were assessed at different ages until 23 y of age. Poisson regression was used to estimate prevalence ratios with adjustment for ≤15 socioeconomic, demographic, maternal, anthropometric, and behavioral covariates.

RESULTS

In the crude analyses, subjects born by CS had ∼50% higher prevalence of obesity at 4, 11, and 15 y of age but not at 23 y of age. After adjustment for covariates, prevalence ratios were markedly reduced and no longer significant for men or women. The only exception was an association for 4-y-old boys in the 1993 cohort, which was not observed in the other 2 cohorts or for girls.

CONCLUSION

In these 3 birth cohorts, CSs do not seem to lead to an important increased risk of obesity during childhood, adolescence, or early adulthood.

Pregnancy outcome and risk of celiac disease in offspring: a nationwide case-control study

BACKGROUND & AIMS

Studies on pregnancy characteristics and mode of delivery and risk of later celiac disease in offspring are inconsistent. In recent decades rates of cesarean delivery and preterm birth survival have increased while at the same time the prevalence of celiac disease has doubled.

METHODS

In this population-based case-control study we examined the risk of celiac disease in individuals exposed to cesarean delivery and adverse fetal events (ie, low Apgar score, small for gestational age, low birth weight, preterm birth, and neonatal infections). Prospectively recorded pregnancy data were obtained from the Swedish Medical Birth Register between 1973 and 2008. Study participants consisted of 11,749 offspring with biopsy-verified celiac disease identified through histopathology reports from Sweden's 28 pathology departments, and 53,887 age- and sex-matched controls from the general population.

RESULTS

We found a positive association between elective cesarean delivery and later celiac disease (adjusted odds ratio [OR], 1.15; 95% confidence interval [CI], 1.04-1.26), but no increased risk of celiac disease after emergency (adjusted OR, 1.02; 95% CI, 0.92-1.13) or any cesarean delivery (adjusted OR, 1.06; 95% CI, 0.99-1.13). Infants born small for gestational age were at a 21% increased risk of celiac disease (95% CI, 1.09-1.35), whereas other pregnancy exposures did not increase the risk of future celiac disease.

CONCLUSIONS

The positive association with elective, but not emergency, cesarean delivery is consistent with the hypothesis that the bacterial flora of the newborn plays a role in the development of celiac disease.

The impact of perinatal immune development on mucosal homeostasis and chronic inflammation

The mucosal surfaces of the gut and airways have important barrier functions and regulate the induction of immunological tolerance. The rapidly increasing incidence of chronic inflammatory disorders of these surfaces, such as inflammatory bowel disease and asthma, indicates that the immune functions of these mucosae are becoming disrupted in humans. Recent data indicate that events in prenatal and neonatal life orchestrate mucosal homeostasis. Several environmental factors promote the perinatal programming of the immune system, including colonization of the gut and airways by commensal microorganisms. These complex microbial-host interactions operate in a delicate temporal and spatial manner and have an important role in the induction of homeostatic mechanisms.

Coeliac disease and pregnancy outcomes

Coeliac disease is a gluten-sensitive enteropathy affecting up to 1% of the population. An accumulating body of evidence supports the association of coeliac disease with adverse pregnancy outcomes, including increased risk of miscarriage and intrauterine growth restriction. Reports differ regarding the extent and severity of these associations, in addition to the exact pathophysiology underlying these associations. Overall, coeliac disease is believed to be a significant condition in pregnancy and reproductive medicine with some advocating the screening of coeliac disease in all pregnant women or some specific high-risk groups.

Cesarean versus vaginal delivery: long-term infant outcomes and the hygiene hypothesis

Concurrent with the trend of increasing cesarean delivery numbers, there has been an epidemic of both autoimmune diseases and allergic diseases. Several theories have emerged suggesting that environmental influences are contributing to this phenomenon, most notably, the hygiene hypothesis. This article provides background about the human microbiota and its relationship to the developing immune system as well as the relationship of mode of delivery on the colonization of the infant intestine, development of the immune system, and subsequent childhood allergies, asthma, and autoimmune diseases.

Pediatric surgery and the human microbiome

Bold advances in the past decade have made it possible to carefully study the contributions of microbes to normal human development and to disease pathogenesis. The intestinal microbiota has been implicated in adult diseases ranging from obesity to cancer, but there have been relatively few investigations of bacteria in surgical diseases of infancy and childhood. In this review, we discuss how novel culture-independent approaches have been harnessed to profile microbes present within clinical specimens. Unique features of the pediatric microbiota and innovative approaches to manipulate the gut flora are also reviewed. Finally, we detail the contributions of gut microbes to 3 diseases relevant to pediatric surgeons: necrotizing enterocolitis, obesity, and inflammatory bowel disease. Current and future research regarding the pediatric microbiota is likely to translate to improved outcomes for infants and children with surgical diseases.

Contribution of the intestinal microbiota to human health: from birth to 100 years of age

Our intestinal tract is colonized since birth by multiple microbial species that show a characteristic succession in time. Notably the establishment of the microbiota in early life is important as it appears to impact later health. While apparently stable in healthy adults, the intestinal microbiota is changing significantly during aging. After 100 years of symbiosis marked changes have been observed that may relate to an increased level of intestinal inflammation. There is considerable interest in the microbiota in health and disease as it may provide functional biomarkers, the possibility to differentiate subjects, and avenues for interventions. This chapter reviews the present state of the art on the research to investigate the contribution of the intestinal microbiota to human health. Specific attention will be given to the healthy microbiota and aberrations due to disturbances such as celiac disease, irritable bowel syndrome, inflammatory bowel disease, obesity and diabetes, and non-alcoholic fatty liver disease.

Reproductive changes associated with celiac disease

Celiac disease is a mucosal disorder of the small intestine that may be triggered by dietary exposure to gluten in genetically-susceptible individuals. The disorder is often associated with diarrhea, malabsorption and weight loss along with other extra-intestinal complications. Reproductive changes have been described, including impaired fertility and adverse pregnancy outcomes possibly related to immune-mediated mechanisms or nutrient deficiency. Other possible pathogenetic factors that may alter placental function include maternal celiac disease autoantibodies binding to placental transglutaminase, and genetic mutations that may facilitate microthrombus formation. Reports noting activation during pregnancy or the puerperium may be important, and suggest that celiac disease may also be hypothetically precipitated by maternal exposure to one or more fetal antigens.

Childbirth experience questionnaire (CEQ): development and evaluation of a multidimensional instrument

Background

Negative experiences of first childbirth increase risks for maternal postpartum depression and may negatively affect mothers' attitudes toward future pregnancies and choice of delivery method. Postpartum questionnaires assessing mothers' childbirth experiences are needed to aid in identifying mothers in need of support and counselling and in isolating areas of labour and birth management and care potentially in need of improvement. The aim of this study was to develop and evaluate a questionnaire for assessing different aspects of first-time mothers' childbirth experiences.

Methods

Childbirth domains were derived from literature searches, discussions with experienced midwives and interviews with first-time mothers. A draft version of the Childbirth Experience Questionnaire (CEQ) was pilot tested for face validity among 25 primiparous women. The revised questionnaire was mailed one month postpartum to 1177 primiparous women with a normal pregnancy and spontaneous onset of active labor and 920 returned evaluable questionnaires. Exploratory factor analysis using principal components analysis and promax rotation was performed to identify dimensions of the childbirth experience. Multitrait scaling analysis was performed to test scaling assumptions and reliability of scales. Discriminant validity was assessed by comparing scores from subgroups known to differ in childbirth experiences.

Results

Factor analysis of the 22 item questionnaire yielded four factors accounting for 54% of the variance. The dimensions were labelled Own capacity, Professional support, Perceived safety, and Participation. Multitrait scaling analysis confirmed the fit of the four-dimensional model and scaling success was achieved in all four sub-scales. The questionnaire showed good sensitivity with dimensions discriminating well between groups hypothesized to differ in experience of childbirth.

Conclusion

The CEQ measures important dimensions of the first childbirth experience and may be used to measure different aspects of maternal satisfaction with labour and birth.