Infection, antibiotic exposure, and risk of celiac disease: A systematic review and meta-analysis

Single cell transcriptome sequencing indicates the cellular heterogeneity of small intestine tissue in celiac disease

Celiac disease (CeD) is an autoimmune small intestinal disease caused by gluten protein ingestion by genetically susceptible individuals. Genome-wide association studies and transcriptomic data have limited capacity to capture intercellular genetic variations. We aimed to construct a single cell transcriptome spectrum, analyze the immune microenvironment and cellular heterogeneity, discover disease-related specific genes and markers, and explore the pathogenesis of CeD. This study performed single cell RNA sequencing (scRNA-seq) on three small intestine biopsies from patients with CeD and three matched healthy Chinese controls. Immunohistochemistry (IHC) and quantitative polymerase chain reaction (qPCR) were used to validate potential diagnostic biomarkers of disease-differential genes. A total of 10 cell subpopulations were annotated, including three types of epithelial and stromal cells and seven types of immune cells. IHC revealed a pronounced overexpression of T cell disease-differential genes, TRAT1, BCL11B, and ETS1 in intraepithelial lymphocytes in the CeD group. Further clinical validation using qPCR confirmed that ETS1 (P = 0.010), TRAT1 (P < 0.001), and BCL11B (P = 0.036) were enriched in the CeD small intestinal tissue. The CD28/CTLA-4 pathway regulates the homeostasis of Treg cells. The IFITs family genes may serve as marker genes for antiviral specific CD4+ T cell subsets. CeD-derived subsets of CD8+ T cells frequently express genes associated with cytotoxicity, including IFNG, GZMK, GZMH, GZMB, SH2D1A, PRF1, and NKG7, as well as genes related to T cell exhaustion, such as PDCD10, CTLA4, TIGIT, PDCD1, and DUSP4. Inflammation and infection pathways were enriched in different cell populations. A single cell expression profile of CeD small intestinal tissue was successfully constructed using scRNA-seq in this study. New biomarkers for CeD-specific histopathology and potential therapeutic targets were discovered, and the biomarkers observed between inflammation and infection pathways were closely related to the onset of CeD.

Elucidating the non-genetic risk factors for celiac disease: an umbrella review of meta-analyses

The breadth and validity of the associations of nongenetic risk factors with celiac disease (CeD) are elusive in the literature. We aimed to evaluate which of these associations have strong epidemiological credibility and assessed presence and extent of potential literature biases. We systematically searched PubMed until April 2024 for systematic reviews and meta-analyses of studies examining associations between putative risk factors and CeD. Each association was categorized in five evidence grades (convincing, highly suggestive, suggestive, weak, and not statistically significant) based on broadly used criteria for evaluating quality of evidence in observational studies. Five eligible publications were included, describing 15 meta-analytic associations on seven nongenetic risk factors, three of which were nominally significant ( P  < 0.05). None of the associations received a strοng or highly suggestive evidence. One meta-analytic association received suggestive evidence, namely any infections during childhood and adulthood for a higher risk of CeD (OR, 1.37; 95% CI, 1.2-1.56; P =3.77 × 10 -6 ). Two meta-analyses reported weak evidence, pertaining to current smoking for a lower risk of CeD (OR, 0.52; 95% CI, 0.32-0.84; P =7.84 × 10 -3 ) and use of antibiotics for a higher risk (OR, 1.2; 95% CI, 1.04-1.38; P 14.8 × 10 -3 ). The rest of the meta-analyses did not report statistically significant results, and pertained to breastfeeding, time of gluten introduction, rotavirus vaccination, and cesarean section. No association of nongenetic risk factors for CeD received high levels of evidence. The evidence was suggestive for the association of any infections during childhood and adulthood with higher risk of CeD. More and prospective future research is warranted.

Celiac Disease in Children: A 2023 Update

Celiac disease (CeD) is a chronic immune-mediated enteropathy, which occurs in genetically predisposed individuals by the ingestion of gluten proteins present in wheat, barley and rye. The global pooled prevalence of CeD is 0.7% and it has been reported from nations all around the globe and can affect individuals of any age. It has a wide clinical spectrum ranging from being asymptomatic to being symptomatic with severe manifestations. Though initial descriptions of CeD focused on the classical presentation with gastrointestinal manifestations, in recent years it has been found that more patients have non-classical manifestations such as anemia, osteoporosis, increased transaminases, failure to thrive or short stature. The definitive diagnosis of CeD is based on a combination of clinical history, serologic testing with/without examination of duodenal biopsies. The preferred initial serologic test regardless of age for the detection of CeD is the tissue transglutaminase (IgA anti-tTG). Children with a high tTG-IgA (≥10 ULN) AND a positive anti-endomysial IgA antibody (EMA) can be diagnosed to have CeD without the need for duodenal biopsies. The rest should undergo biopsies with at least 4 biopsies from the distal duodenum and at least 1 from the bulb. A correctly orientated biopsy showing increased intraepithelial cells and a villous to crypt ratio of <2 is suggestive of CeD. The management of CeD is a lifelong complete dietary avoidance of gluten. IgA-TGA acts as a surrogate marker for healing of the small-bowel mucosa and should be performed every 6 mo until normalization and then every 12-24 mo thereafter.

Effect of helicobacter pylori infection eradication on serum level of anti-tissue transglutaminase in children with celiac disease

BACKGROUND

Evidence shows the increase of anti-tissue transglutaminase (tTG) levels in various conditions, including infectious agents, independently of celiac disease (CD). The aim of this study was to investigate the effect of helicobacter pylori (H.pylori) infection eradication on serum level of tTG in children with CD.

METHODS

This study was conducted on children aged 2 to 18 who referred to reference hospitals for diagnosis of CD. After upper endoscopy and biopsy to confirm CD and H.pylori infection, the children were divided into three groups (including group one: 16 CD patients with positive H. pylori; group two: 16 non-CD patients with positive H. pylori; and group three: 56 CD patients with negative H. pylori), respectively. The tTG level in study groups were compared after the eradication of H.pylori.

RESULTS

The mean age of the subjects in the group one, two, and three was 9.7 ± 3.33, 11.8 ± 3.14, and 7.6 ± 3.32 years, respectively. Our results showed that in group one, mean tTG increased after eradication of H.pylori infection, however, these changes were not significant (182.43 vs. 157.18, P = 0.121). In the second group, although unlike the first group, mean tTG decreased after eradication of the infection, but still these changes were not significant (9.56 vs. 22.18, P = 0.449). Furthermore, at the baseline level, the mean tTG in the group three was closer to the mean tTG in the first group.

CONCLUSION

Our findings showed that the eradication of H.pylori infection does not have a significant effect on tTG levels in children with and without CD.

Antibiotics in the pathogenesis of diabetes and inflammatory diseases of the gastrointestinal tract

Antibiotic use is increasing worldwide. However, the use of antibiotics is clearly associated with changes in gut microbiome composition and function, and perturbations have been identified as potential environmental risk factors for chronic inflammatory disorders of the gastrointestinal tract. In this Review, we examine the association between the use of antibiotics and the onset and development of both type 1 and type 2 diabetes, inflammatory bowel disease, including ulcerative colitis and Crohn's disease, as well as coeliac disease and eosinophilic oesophagitis. We discuss the key findings of epidemiological studies, provide mechanistic insights into the pathways by which the gut microbiota might contribute to these diseases, and assess clinical trials investigating the effects of antibiotics. Such studies indicate that antibiotic exposures, varying in type, timing and dosage, could explain differences in disease risk. There seems to be a critical window in early life in which perturbation of the microbiome has a substantial effect on disease development. Identifying the antibiotic-perturbed gut microbiota as a factor that contributes to the pathophysiology of these inflammatory disorders might stimulate new approaches to prevention, diagnosis and treatment.

Why are western diet and western lifestyle pro-inflammatory risk factors of celiac disease?

The prevalence of celiac disease increased in recent years. In addition to the genetic and immunological factors, it appears that environmental determinants are also involved in the pathophysiology of celiac disease. Gastrointestinal infections impact the development of celiac disease. Current research does not directly confirm the protective effect of natural childbirth and breastfeeding on celiac disease. However, it seems that in genetically predisposed children, the amount of gluten introduced into the diet may have an impact on celiac disease development. Also western lifestyle, including western dietary patterns high in fat, sugar, and gliadin, potentially may increase the risk of celiac disease due to changes in intestinal microbiota, intestinal permeability, or mucosal inflammation. Further research is needed to expand the knowledge of the relationship between environmental factors and the development of celiac disease to define evidence-based preventive interventions against the development of celiac disease. The manuscript summarizes current knowledge on factors predisposing to the development of celiac disease including factors associated with the western lifestyle.

Review article: Epidemiology of coeliac disease

Coeliac disease is an immune-mediated disease caused by ingestion of gluten in genetically susceptible individuals. Coeliac disease has been thought to affect mainly people of European origin but subsequently many studies revealed that it affects people living in North America, Oceania, South America, Asia as well as Africa. The global pooled seroprevalence and prevalence of biopsy-confirmed coeliac disease are 1.4% and 0.7% respectively. The pooled incidence rates in women and men are 17.4 (95% CI: 13.7-21.1) and 7.8 (95% CI: 6.3-9.2) per 100 000 person-years respectively. The systematic reviews, based on many population-based data, suggest that both the prevalence and the incidence of coeliac disease has increased over past three decades, which may be attributable not only to an increase in the detection rate (improvement in diagnostic tests, simplification of diagnostic criteria and increase in awareness about the disease) but also because of modernisation and globalisation related changes in the dietary practices including increase in the use of convenience food and dietary gluten. In addition to genetic factors, while there are many environmental risk factors, including age at the first introduction of gluten, breastfeeding, caesarean section, exposure to antibiotics and gut microbiome; the amount of gluten ingestion during early part of life, however, has been shown to increase the risk of coeliac disease, and this is relevant from the point of view of primary prevention. In this review, we have reviewed and summarised the literature, up till year 2021, related to the global and continent-wise epidemiology and risk factors associated with coeliac disease.

Adherence to Gluten-Free Diet Restores Alpha Diversity in Celiac People but the Microbiome Composition Is Different to Healthy People

Celiac disease (CD) is an autoimmune disease with the destruction of small intestinal villi, which occurs in genetically predisposed individuals. At the present moment, a gluten-free diet (GFD) is the only way to restore the functionality of gut mucosa. However, there is an open debate on the effects of long-term supplementation through a GFD, because some authors report an unbalance in microbial taxa composition. Methods: For microbiome analysis, fecal specimens were collected from 46 CD individuals in GFD for at least 2 years and 30 specimens from the healthy controls (HC). Data were analyzed using an ensemble of software packages: QIIME2, Coda-lasso, Clr-lasso, Selbal, PICRUSt2, ALDEx2, dissimilarity-overlap analysis, and dysbiosis detection tests. Results: The adherence to GFD restored the alpha biodiversity of the gut microbiota in celiac people but microbial composition at beta diversity resulted as different to HC. The microbial composition of the CD subjects was decreased in a number of taxa, namely Bifidobacterium longum and several belonging to Lachnospiraceae family, whereas Bacteroides genus was found to be more abundant. Predicted metabolic pathways among the CD bacterial communities revealed an important role in tetrapyrrole biosynthesis. Conclusions: CD patients in GFD had a non-dysbiotic microbial composition for the crude alpha diversity metrics. We found significant differences in beta diversity, in certain taxon, and pathways between subjects with inactive CD in GFD and controls. Collectively, our data may suggest the development of new GFD products by modulating the gut microbiota through diet, supplements of vitamins, and the addition of specific prebiotics.

Cesarean section is not associated with increased risk of celiac disease in the offspring: a meta-analysis

OBJECTIVE

Epidemiologic findings are inconsistent concerning the association between cesarean section (C-section) and celiac disease in offspring.

METHODS

We performed a systematic literature search of PubMed and Embase databases until July 2021. A meta-analysis was performed for each outcome in which a summary odds ratio (OR) was calculated while taking heterogeneity into account.

RESULTS

A total of 11 observational were identified for the literature review. We found that C-section was not associated with an increase in the risk of CD (OR = 1.03, 95% CI, 0.95-1.12; p = .501). In subgroup analyses, the association remained insignificant for both infants born after elective C-section (OR 1.05; 0.95-1.16; p = .329) and emergency C-section (OR 1.06; 1-1.13; p = .051).

CONCLUSIONS

Our results indicate that C-section is not associated with CD in offspring.

Checkpoint Inhibitors and Induction of Celiac Disease-like Condition

Immune checkpoint inhibitors herald a new era in oncological therapy-resistant cancer, thus bringing hope for better outcomes and quality of life for patients. However, as with other medications, they are not without serious side effects over time. Despite this, their advantages outweigh their disadvantages. Understanding the adverse effects will help therapists locate, apprehend, treat, and perhaps diminish them. The major ones are termed immune-related adverse events (irAEs), representing their auto-immunogenic capacity. This narrative review concentrates on the immune checkpoint inhibitors induced celiac disease (CD), highlighting the importance of the costimulatory inhibitors in CD evolvement and suggesting several mechanisms for CD induction. Unraveling those cross-talks and pathways might reveal some new therapeutic strategies.

Investigation of multidrug-resistant Helicobacter pylori in pediatric patients: A Bulgarian study and literature data

Antibiotic resistance of Helicobacter pylori strains from 106 symptomatic children was evaluated according to EUCAST breakpoints and rate of multidrug resistance (MDR) was analyzed. Overall resistance rates were amoxicillin 7.5%, metronidazole 25.5%, clarithromycin 34.0% and ciprofloxacin 14.1%. There were no significant differences in resistance rates according to patients' age (2-6 and 7-18 years) and sex. Combined resistance rate was 19.8%, including double, triple, and quadruple resistance in 13.2% (14 strains), 5.7% (6) and 0.9% (1) of the strains, respectively. MDR was found in 5.9% (5/84) of the children with gastritis and in two of the four children with celiac disease. The MDR was present in three children aged 4-6 years and in four children aged 10-17 years. The total MDR rate (6.6%) in Bulgarian children in 2012-2021 was higher than those in other studies based on EUCAST breakpoints such as those in pediatric patients in Slovenia in 2011-2014 (3.8%), Lithuania in 2013-2015 (0%) and Spain in 2014-2019 (0%), although being lower than those (20.7% in the untreated and 47.0% in the treated children) in China in 2019. In brief, it is of concern that MDR can strongly limit the choice of H. pylori therapy of one out of fifteen Bulgarian children and that overall resistance to both metronidazole and clarithromycin can hinder the treatment of 15.1% of the pediatric patients. Susceptibility-guided tailored eradication therapy of H. pylori infection should be more frequently implemented in the symptomatic children to avoid risks of both the infection itself and multiple antibiotic treatments.

Cesarean delivery and risk of hospitalization for autoimmune disorders before 14 years of age

It is supposed that cesarean birth is implicated in the development of autoimmunity. We evaluated the association between cesarean delivery and the risk of hospitalization for autoimmune disease in children up to 14 years of age. We performed a longitudinal cohort study of 934,873 children born between 2006 and 2019 in Quebec, Canada. The main exposure measure was cesarean delivery versus vaginal delivery (spontaneous or induced). Outcomes included hospitalization for type 1 diabetes, celiac disease, or other autoimmune disorders before 14 years of age. We used Cox regression models to estimate hazard ratios (HR) and 95% confidence intervals (CI) for the association between cesarean delivery and hospitalization for autoimmune disorders, adjusted for patient characteristics. A total of 248,963 children (27%) were delivered by cesarean. Median length of follow-up was 7.4 years. The hospitalization rate for autoimmune disorders was 69.1 per 100,000 person-years for cesarean and 65.9 per 100,000 person-years for vaginal delivery. Cesarean delivery was not associated with autoimmune disorders overall (HR 1.02, 95% CI 0.96-1.10). There was no association with type 1 diabetes (HR 1.00, 95% CI 0.85-1.17), celiac disease (HR 0.86, 95% CI 0.71-1.04), inflammatory bowel disease (HR 1.15, 95% CI 0.88-1.49), or idiopathic thrombocytopenic purpura (HR 1.01, 95% CI 0.82-1.25). Cesarean delivery was not associated with autoimmune disorders at different ages.Conclusion: This study suggests that cesarean delivery is not associated with the risk of hospitalization for autoimmune disorders before 14 years of age. Delivery mode does not seem to mediate the risk of autoimmunity in childhood. What is Known: • Children born by cesarean may be at risk of abnormal immune development. • The association between cesarean delivery and risk of pediatric autoimmune disorders is unclear. What is New: • In this cohort study of over 900,000 children, cesarean delivery was not associated with the risk of hospitalization for a range of autoimmune disorders before 14 years of age. • Cesarean delivery may not be related to the development of autoimmunity.

Infection threat shapes our social instincts

We social animals must balance the need to avoid infections with the need to interact with conspecifics. To that end we have evolved, alongside our physiological immune system, a suite of behaviors devised to deal with potentially contagious individuals. Focusing mostly on humans, the current review describes the design and biological innards of this behavioral immune system, laying out how infection threat shapes sociality and sociality shapes infection threat. The paper shows how the danger of contagion is detected and posted to the brain; how it affects individuals’ mate choice and sex life; why it strengthens ties within groups but severs those between them, leading to hostility toward anyone who looks, smells, or behaves unusually; and how it permeates the foundation of our moral and political views. This system was already in place when agriculture and animal domestication set off a massive increase in our population density, personal connections, and interaction with other species, amplifying enormously the spread of disease. Alas, pandemics such as COVID-19 not only are a disaster for public health, but, by rousing millions of behavioral immune systems, could prove a threat to harmonious cohabitation too.

Maternal exposures and the infant gut microbiome: a systematic review with meta-analysis

Early life, including the establishment of the intestinal microbiome, represents a critical window of growth and development. Postnatal factors affecting the microbiome, including mode of delivery, feeding type, and antibiotic exposure have been widely investigated, but questions remain regarding the influence of exposures in utero on infant gut microbiome assembly. This systematic review aimed to synthesize evidence on exposures before birth, which affect the early intestinal microbiome. Five databases were searched in August 2019 for studies exploring pre-pregnancy or pregnancy 'exposure' data in relation to the infant microbiome. Of 1,441 publications identified, 76 were included. Factors reported influencing microbiome composition and diversity included maternal antibiotic and probiotic uses, dietary intake, pre-pregnancy body mass index (BMI), gestational weight gain (GWG), diabetes, mood, and others. Eleven studies contributed to three meta-analyses quantifying associations between maternal intrapartum antibiotic exposure (IAP), BMI and GWG, and infant microbiome alpha diversity (Shannon Index). IAP, maternal overweight/obesity and excessive GWG were all associated with reduced diversity. Most studies were observational, few included early recruitment or longitudinal follow-up, and the timing, frequency, and methodologies related to stool sampling and analysis were variable. Standardization and collaboration are imperative to enhance understanding in this complex and rapidly evolving area.

Early life antibiotics and childhood gastrointestinal disorders: a systematic review

BACKGROUND

In adults, there is increasing evidence for an association between antibiotic use and gastrointestinal (GI) disorders but in children, the evidence is scarce.

OBJECTIVE

Assess the association between exposure to antibiotics in the first 2 years of life in term born children and the presence of chronic GI disorders later in childhood.

DESIGN

For this systematic review the MEDLINE, Embase, WHO trial register and Web of Science were systematically searched from inception to 8 June 2020. Title and abstract screening (n=12 219), full-text screening (n=132) as well as the quality assessment with the Newcastle-Ottawa Scale were independently performed by two researchers.

MAIN OUTCOME MEASURES

The association between antibiotics and inflammatory bowel disease (IBD) (n=6), eosinophilic oesophagitis (EoE) (n=5), coeliac disease (CeD) (n=6), infantile colics (n=3), functional constipation (n=2), recurrent abdominal pain, regurgitation, functional diarrhoea and infant dyschezia were examined.

RESULTS

Twenty-two studies were included, 11 cohort and 11 case-control studies. A best evidence synthesis showed strong evidence for an association between antibiotic exposure in the first 2 years of life and the presence of IBD, and CeD during childhood. Moderate evidence was found for an association with EoE and no association with functional constipation in the first year of life. There was insufficient evidence for the other studied disorders.

CONCLUSIONS

The use of antibiotics in early life may increase the risk of GI disorders later in life. Further studies are necessary to unravel the underlying mechanisms and determine potential preventive measures. Meanwhile judicious use of antibiotics in early childhood is highly warranted.

PROSPERO REGISTRATION NUMBER

PROSPERO CRD42019132631.

Alterations in Intestinal Microbiota of Children With Celiac Disease at the Time of Diagnosis and on a Gluten-free Diet

BACKGROUND AND AIMS

It is not clear whether alterations in the intestinal microbiota of children with celiac disease (CD) cause the disease or are a result of disease and/or its treatment with a gluten-free diet (GFD).

METHODS

We obtained 167 fecal samples from 141 children (20 with new-onset CD, 45 treated with a GFD, 57 healthy children, and 19 unaffected siblings of children with CD) in Glasgow, Scotland. Samples were analyzed by 16S ribosomal RNA sequencing, and diet-related metabolites were measured by gas chromatography. We obtained fecal samples from 13 children with new-onset CD after 6 and 12 months on a GFD. Relationships between microbiota with diet composition, gastrointestinal function, and biomarkers of GFD compliance were explored.

RESULTS

Microbiota α diversity did not differ among groups. Microbial dysbiosis was not observed in children with new-onset CD. In contrast, 2.8% (Bray-Curtis dissimilarity index, P = .025) and 2.5% (UniFrac distances, P = .027) of the variation in microbiota composition could be explained by the GFD. Between 3% and 5% of all taxa differed among all group comparisons. Eleven distinctive operational taxonomic units composed a microbe signature specific to CD with high diagnostic probability. Most operational taxonomic units that differed between patients on a GFD with new-onset CD vs healthy children were associated with nutrient and food group intake (from 75% to 94%) and with biomarkers of gluten ingestion. Fecal levels of butyrate and ammonia decreased during the GFD.

CONCLUSIONS

Although several alterations in the intestinal microbiota of children with established CD appear to be effects of a GFD, specific bacteria were found to be distinct biomarkers of CD. Studies are needed to determine whether these bacteria contribute to pathogenesis of CD.