Prediction Models for Celiac Disease Development in Children From High-Risk Families: Data From the PreventCD Cohort.

BACKGROUND & AIMS: Screening for celiac disease (CD) is recommended in children with affected first-degree relatives (FDR). However, the frequency of screening and at what age remain unknown. The aims of this study were to detect variables influencing the risk of CD development and develop and validate clinical prediction models to provide individualized screening advice. METHODS: We analyzed prospective data from the 10 years of follow-up of the PreventCD-birth cohort involving 944 genetically predisposed children with CD-FDR. Variables significantly influencing the CD risk were combined to determine a risk score. Landmark analyses were performed at different ages. Prediction models were created using multivariable Cox proportional hazards regression analyses, backward elimination, and Harrell's c-index for discrimination. Validation was done using data from the independent NeoCel cohort. RESULTS: In March 2019, the median follow-up was 8.3 years (22 days-12.0 years); 135/944 children developed CD (mean age, 4.3 years [range, 1.1-11.4]). CD developed significantly more often in girls (P = .005) and in Human Leukocyte Antigen (HLA)-DQ2 homozygous individuals (8-year cumulative incidence rate of 35.4% vs maximum of the other HLA-risk groups 18.2% [P < .001]). The effect of homozygosity DR3-DQ2/DR7-DQ2 on CD development was only present in girls (interaction P = .04). The prediction models showed good fit in the validation cohort (Cox regression 0.81 [0.54]). To calculate a personalized risk of CD development and provide screening advice, we designed the Prediction application https://hputter.shinyapps.io/preventcd/. CONCLUSION: Children with CD-FDR develop CD early in life, and their risk depends on gender, age and HLA-DQ, which are all factors that are important for sound screening advice. These children should be screened early in life, including HLA-DQ2/8-typing, and if genetically predisposed to CD, they should get further personalized screening advice using our Prediction application. TRIAL REGISTRATION NUMBER: ISRCTN74582487 (https://www.isrctn.com/search?q=ISRCTN74582487).

ESPGHAN Position Paper on Management and Follow-up of Children and Adolescents With Celiac Disease.

OBJECTIVES: To gather the current evidence and to offer recommendations for follow-up and management. METHODS: The Special Interest Group on Celiac Diseases of the European Society of Paediatric Gastroenterology Hepatology and Nutrition formulated ten questions considered to be essential for follow-up care. A literature search (January 2010-March 2020) was performed in PubMed or Medline. Relevant publications were identified and potentially eligible studies were assessed. Statements and recommendations were developed and discussed by all coauthors. Recommendations were voted upon: joint agreement was set as at least 85%. RESULTS: Publications (n = 2775) were identified and 164 were included. Using evidence or expert opinion, 37 recommendations were formulated on: The need to perform follow-up, its frequency and what should be assessed, how to assess adherence to the gluten-free diet, when to expect catch-up growth, how to treat anemia, how to approach persistent high serum levels of antibodies against tissue-transglutaminase, the indication to perform biopsies, assessment of quality of life, management of children with unclear diagnosis for which a gluten-challenge is indicated, children with associated type 1 diabetes or IgA deficiency, cases of potential celiac disease, which professionals should perform follow-up, how to improve the communication to patients and their parents/caregivers and transition from pediatric to adult health care. CONCLUSIONS: We offer recommendations to improve follow-up of children and adolescents with celiac disease and highlight gaps that should be investigated to further improve management.

Influence of HLA on clinical and analytical features of pediatric celiac disease.

BACKGROUND: Celiac disease (CD) is triggered by gluten and related prolamines in genetically susceptible individuals. We aimed to investigate the influence of HLA-DQ genotypes in clinical, serological and histological features related to CD. METHODS: A retrospective observational study was performed including 463 Spanish patients with biopsy-proven CD. Clinical, serological, histological and HLA-DQ genetic data were collected from each participant. The presence of a family history of CD was also considered. Bivariate (chi-square tests or the Fisher's exact test) and multivariate (logistic regression after adjusting for age and sex) analyses were performed to assess the association between clinical and laboratory parameters with HLA-DQ. RESULTS: A predominance of females (62%), classical clinical presentation (86%) and positive anti-transglutaminase 2/endomysium antibodies (99%) was observed in our sample, with a mean age at onset of 2.6 ± 0.1 years. Five percent of our patients were first-degree relatives of subjects with CD, with HLA-DQ genetics showing increased homozygosity of HLA-DQ2.5 (p = 0.03) and HLA-DQ8 (p = 0.09). In the non-CD family history group, an association between delayed disease onset and HLA-DQ8 carriage was observed (p < 0.001), besides an influence of HLA-DQB1*02 gene dosage on clinical presentation and severity of histological damage (after adjusting for age and sex, p = 0.05 and p = 0.02, respectively) and a trend towards presence of specific antibodies (p = 0.09). These associations could not be evaluated properly in the group of patients with affected first-degree relatives due to the small sample size. CONCLUSIONS: HLA-DQ genotypic frequencies differ slightly between CD patients depending on their family history of CD. In patients lacking CD first-degree relatives, carriage of HLA-DQ2.5 with double dose of HLA-DQB1*02 seems to be associated with classical clinical presentation and more severe histological damage.

Bifidobacterium longum subsp infantis CECT7210-supplemented formula reduces diarrhea in healthy infants: a randomized controlled trial.

BackgroundIntestinal microbiota of breast-fed infants is plenty of beneficial bifidobacteria. We aimed to determine whether an infant formula supplemented with probiotic Bifidobacterium longum subsp. infantis CECT7210 (B. infantis IM1) is effective at reducing diarrhea incidence in healthy term infants.MethodsDouble-blinded, randomized, multicenter, controlled clinical trial, where formula-fed infants (<3 months) received an infant formula supplemented (Probiotic) or not (Control) with 107 cfu/g of B. infantis IM1 over 12 weeks. Diarrheas, growth, digestive symptoms, stool bifidobacteria, and microbiota were assessed.ResultsIn all, 97 (Control) and 93 (Probiotic) infants were randomized, and 78 (Control) and 73 (Probiotic) completed the 12 week-follow-up. In the overall study period, a median of 0.29±1.07 and 0.05±0.28 diarrhea events/infant was observed in the Control and Probiotic groups, respectively (P=0.059). This trend to less diarrhea episodes in the Probiotic group reached statistical significance at 8 weeks (0.12±0.47 vs. 0.0±0.0 events/infant, P=0.047). Constipation incidence was higher (odds ratio (OR) 2.67 (1.09-6.50)) and stool frequency lower (2.0±1.0 vs. 2.6±1.3 stools/day, P=0.038) in the Control group after 4 weeks. No differences were found at other time points nor in other digestive symptoms, growth, or formula intake.ConclusionA B. infantis IM1-supplemented infant formula may reduce diarrhea episodes, being safe, well tolerated, and associated with lower constipation prevalence.

Anti-gliadin antibodies in breast milk from celiac mothers on a gluten-free diet.

PURPOSE: To analyze the presence of total IgA and anti-gliadin antibodies (AGA) in BM from CD mothers who follow a gluten-free diet (GFD) and from mothers on a normal gluten-containing diet (ND). METHODS: 218 samples of mature milk were obtained at different months of lactation (1-6) from 83 mothers (2 or more samples per mother) from Italy (Naples), The Netherlands (Leiden) and Spain (Madrid, Valencia and Reus): 42 CD mothers on GFD for more than 2 years and 41 non-CD mothers on a ND. Whey samples were analyzed for AGA-IgA by an indirect homemade ELISA and for total IgA (g/L) by a commercial ELISA kit. RESULTS: AGA-IgA was detected in BM, both in mothers on a GFD and mothers on a ND. AGA-IgA levels in both groups of mothers, CD and non-CD, show the same trend towards decreasing slightly along the months of lactation (p = 0.91). A different trend is observed for total IgA levels, decreasing markedly in CD mothers from the first month of lactation onwards but remaining stable in non-CD mothers (p = 0.048). A statistically significant association was found between the means of total IgA and AGA-IgA (p < 0.001). CONCLUSION: AGA-IgA is present in BM from mothers on a ND as well as in BM from mothers who had been on a GFD for years. This reflects the existence of a long-lasting immunological memory independent of the mother's diet. If the presence of these antibodies has any role in promoting the acquisition of gluten tolerance in the infant, our study shows that children of CD mothers would be on equal conditions as children of non-CD mothers.

HLA-DQ distribution and risk assessment of celiac disease in a Spanish center.

AIMS: celiac disease is a multisystem immune-mediated disease triggered by gluten in genetically susceptible individuals. The HLA-DQ2 and/or HLA-DQ8 heterodimers are encoded by the main genetic predisposing factors and their presence is required for the development of the immunological response that leads to the disease. However, the HLA-conferred risk can differ within different countries. The aim of the study was to analyze the risk of Spanish children to develop celiac disease according to their HLA-DQ genotype. METHODS: a retrospective observational case-control study was performed using a sample of 475 celiac patients and 628 controls. RESULTS: children carrying the HLA-DQ2.5 had the highest disease risk, especially those with two HLA-DQB1*02 alleles. A similar high risk was observed in HLA-DQ8 homozygous individuals. A risk conferred by HLA-DQ8 in heterozygosity and HLA-DQ2.2 was also found and two patients with celiac disease carried the HLA-DQ7.5 haplotype as the only HLA risk factor. CONCLUSIONS: there are four genetic risk categories according to the HLA-DQ genotype. The HLA-DQ7.5 genotype does not confer risk but should not be used to rule out celiac disease when a high suspicion of the disease exists. These findings could be relevant to determine when to perform serological screening in asymptomatic subjects at risk of celiac disease.

Ten years of follow-up of the Spanish cohort of the European PreventCD study: the lessons learned.

AIM: to evaluate the influence of gluten consumption on celiac disease development and to describe its natural history in the Spanish cohort of the European PreventCD study. METHODS: prospective multi-center double blind study of 225 children that were followed up from birth. All cases were HLA-DQ2/HLA-DQ8 positive with a 1st degree relative with celiac disease and were followed up in three centers from Madrid, Reus and Valencia. Gluten intake was determined between four and ten months according to the protocol. Gluten intake was ad libitum between eleven and 36 months and was prospectively quantified by means of dietary records. Clinical visits and specific antibody analysis for celiac disease were performed periodically. RESULTS: twenty-six cases were diagnosed, all had a positive biopsy and serology; 21 had gastrointestinal symptoms and five were asymptomatic. In addition, 2,565 food records were analyzed and statistically significant differences (p < 0.001) were found with regard to gluten consumption among the three centers, although not between celiac and non-celiac children (p = 0.025). The HLA-DQ2.5/DQ2.5 and DQ2.5/DQ2.2 genotypes had a relative risk of 4.7 (95% CI: 0.80-27.55; p = 0.08), which was higher than for the rest of genotypes. Female gender also had a relative risk that was five times higher than that for males. CONCLUSIONS: the amount of gluten intake between 11 and 36 months or the duration of breast feeding were not risk factors for the development of CD in the Spanish population. The HLA genotype and gender were the most relevant associated factors. In this at-risk group, the disease presented before two years of age in the majority of the cases with a weak clinical expression.

Consensus document on exclusion diets in irritable bowel syndrome (IBS).

This paper summarizes the contents of a consensus document on exclusion diets in irritable bowel disease that was developed by a task force from SEPD, FEAD, SENPE, FESNAD, SEÑ, SEEN, SEGHNP, SEDCA and ADENYD. The complete document is available at the SEPD website. Irritable bowel syndrome is a highly prevalent functional digestive disorder where, in addition to drugs, therapy includes diet and acquisition of healthy habits as basic elements for its control. In order to facilitate dietary counseling for these patients in daily practice, the present consensus document on the role of exclusion diets was developed. To this end, consensus opinions were collected from various experts in the national scientific societies aiming at establishing recommendations applicable to the health care of patients with irritable bowel syndrome.

Randomized feeding intervention in infants at high risk for celiac disease.

BACKGROUND: A window of opportunity has been suggested for reducing the risk of celiac disease by introducing gluten to infants at 4 to 6 months of age. METHODS: We performed a multicenter, randomized, double-blind, placebo-controlled dietary-intervention study involving 944 children who were positive for HLA-DQ2 or HLA-DQ8 and had at least one first-degree relative with celiac disease. From 16 to 24 weeks of age, 475 participants received 100 mg of immunologically active gluten daily, and 469 received placebo. Anti-transglutaminase type 2 and antigliadin antibodies were periodically measured. The primary outcome was the frequency of biopsy-confirmed celiac disease at 3 years of age. RESULTS: Celiac disease was confirmed by means of biopsies in 77 children. To avoid underestimation of the frequency of celiac disease, 3 additional children who received a diagnosis of celiac disease according to the 2012 European Society for Pediatric Gastroenterology, Hepatology, and Nutrition diagnostic criteria (without having undergone biopsies) were included in the analyses (80 children; median age, 2.8 years; 59% were girls). The cumulative incidence of celiac disease among patients 3 years of age was 5.2% (95% confidence interval [CI], 3.6 to 6.8), with similar rates in the gluten group and the placebo group (5.9% [95% CI, 3.7 to 8.1] and 4.5% [95% CI, 2.5 to 6.5], respectively; hazard ratio in the gluten group, 1.23; 95% CI, 0.79 to 1.91). Rates of elevated levels of anti-transglutaminase type 2 and antigliadin antibodies were also similar in the two study groups (7.0% [95% CI, 4.7 to 9.4] in the gluten group and 5.7% [95% CI, 3.5 to 7.9] in the placebo group; hazard ratio, 1.14; 95% CI, 0.76 to 1.73). Breast-feeding, regardless of whether it was exclusive or whether it was ongoing during gluten introduction, did not significantly influence the development of celiac disease or the effect of the intervention. CONCLUSIONS: As compared with placebo, the introduction of small quantities of gluten at 16 to 24 weeks of age did not reduce the risk of celiac disease by 3 years of age in this group of high-risk children. (Funded by the European Commission and others; PreventCD Current Controlled Trials number, ISRCTN74582487.).

Efficacy of a point-of-care test based on deamidated gliadin peptides for the detection of celiac disease in pediatric patients.

OBJECTIVE: The objective of the study was to assess the effectiveness of a point-of-care test (POCT) based on deamidated gliadin peptides (DGP) compared to the European Society for Paediatric Gastroenterology Hepatology and Nutrition (ESPGHAN) criteria diagnosis in the early detection of celiac disease (CD) in pediatric patients. METHODS: One hundred children (≤ 18 years) with suspected CD were selected, including siblings of celiac children that underwent gastroscopy for other gastrointestinal conditions. Patients with severe disease, following a gluten-free diet (GFD), with gastrointestinal bleeding, coagulopathy and infections in the last month were excluded. All children were evaluated with a POCT that detects immunoglobulin A (IgA) and immunoglobulin G (IgG) antibodies to DGP and total IgA. The POCT results were compared to CD diagnosis according to current ESPGHAN criteria. This involved the detection of IgA tissue transglutaminase (tTG) antibodies, the results of an intestinal biopsy and genetic testing. RESULTS: The prevalence of CD found in the present study was 48% (95% confidence interval in parenthesis 37.9-58.2%). The results of the POCT were concordant with the CD diagnosis made according to ESPGHAN criteria: 95.8% (85.7-99.4%) sensitivity, 98.1% (89.7-99.7%) specificity, 97.9% (88.7-99.6%) positive predictive value and 96.2% (87.0-99.4%) negative predictive value. Positive and negative likelihood ratios were 49.8 (7.2-347.5) and 0.04 (0.01-0.17), respectively. The POCT showed a 100% diagnostic accuracy in children younger than ten years of age. In total, three discordant results were found. CONCLUSION: Due to the high diagnostic accuracy in the pediatric population, the POCT can be considered as an effective tool for the early diagnosis of CD, especially in patients younger than ten years of age.

Investigating the early metabolic fingerprint of celiac disease - a prospective approach.

OBJECTIVES AND STUDY: In the development of Celiac Disease (CD) both genetic and environmental factors play a crucial role. The Human Leukocyte Antigen (HLA)-DQ2 and HLA-DQ8 loci are strongly related to the disease and are necessary but not sufficient for the development of CD. Therefore, increasing interest lies in examining the mechanisms of CD onset from the early beginning. Differences in serum and urine metabolic profiles between healthy individuals and CD patients have been reported previously. We aimed to investigate if the metabolic pathways were already altered in young, 4 month old infants, preceding the CD diagnosis. METHODS: Serum samples were available for 230 four month old infants of the PreventCD project, a multicenter, randomized, double-blind, dietary intervention study. All children were positive for HLA-DQ2 and/or HLA-DQ8 and had at least one first-degree relative diagnosed with CD. Amino acids were quantified after derivatization with liquid chromatography - tandem mass spectrometry (MS/MS) and polar lipid concentrations (acylcarnitines, lysophosphatidylcholines, phosphatidylcholines, and sphingomyelins) were determined with direct infusion MS/MS. We investigated the association of the metabolic profile with (1) the development of CD up to the age of 8 years (yes/no), (2) with HLA-risk groups, (3) with the age at CD diagnosis, using linear mixed models and cox proportional hazards models. Gender, intervention group, and age at blood withdrawal were included as potential confounder. RESULTS: By the end of 2014, thirty-three out of the 230 children (14%) were diagnosed with CD according to the ESPGHAN criteria. Median age at diagnosis was 3.4 years (IQR, 2.4-5.2). Testing each metabolite for a difference in the mean between healthy and CD children, we (1) could not identify a discriminant analyte or a pattern pointing towards an altered metabolism (Bonferroni corrected P > 0.05 for all). Metabolite concentrations (2) did not differ across the HLA-risk groups. When investigating the age at diagnosis using (3) survival models, we found no evidence for an association between the metabolic profile and the risk of a later CD diagnosis. CONCLUSION: The metabolic profile at 4 months of age was not predictive for the development of CD up to the age of 8 years. Our results suggest that metabolic pathways reflected in serum are affected only later in life and that the HLA-genotype does not influence the serum metabolic profile in young infants before introduction of solid food.

Gluten Introduction and the Risk of Coeliac Disease: A Position Paper by the European Society for Pediatric Gastroenterology, Hepatology, and Nutrition.

BACKGROUND: The European Society for Paediatric Gastroenterology, Hepatology and Nutrition recommended in 2008, based on observational data, to avoid both early (<4 months) and late (≥7 months) introduction of gluten and to introduce gluten while the infant is still being breast-fed. New evidence prompted ESPGHAN to revise these recommendations. OBJECTIVE: To provide updated recommendations regarding gluten introduction in infants and the risk of developing coeliac disease (CD) during childhood. SUMMARY: The risk of inducing CD through a gluten-containing diet exclusively applies to persons carrying at least one of the CD risk alleles. Because genetic risk alleles are generally not known in an infant at the time of solid food introduction, the following recommendations apply to all infants, although they are derived from studying families with first-degree relatives with CD. Although breast-feeding should be promoted for its other well-established health benefits, neither any breast-feeding nor breast-feeding during gluten introduction has been shown to reduce the risk of CD. Gluten may be introduced into the infant's diet anytime between 4 and 12 completed months of age. In children at high risk for CD, earlier introduction of gluten (4 vs 6 months or 6 vs 12 months) is associated with earlier development of CD autoimmunity (defined as positive serology) and CD, but the cumulative incidence of each in later childhood is similar. Based on observational data pointing to the association between the amount of gluten intake and risk of CD, consumption of large quantities of gluten should be avoided during the first weeks after gluten introduction and during infancy. The optimal amounts of gluten to be introduced at weaning, however, have not been established.

Influence of breastfeeding versus formula feeding on lymphocyte subsets in infants at risk of coeliac disease: the PROFICEL study.

PURPOSE: In addition to genetic risk, environmental factors might influence coeliac disease (CD) development. We sought to assess the effect of the interaction between milk-feeding practices and the HLA-DQ genotype on peripheral lymphocyte subsets and their activation markers in infants at familial risk for CD. METHODS: 170 newborns were classified in 3 different genetic risk groups (high risk, HR; intermediate risk, IR; and low risk, LR) after DQB1 and DQA1 typing. Lymphocyte subsets were studied at the age of 4 months by flow cytometry analysis. RESULTS: 79 infants were receiving exclusive breastfeeding (BF) and 91 partial breastfeeding or formula feeding (FF). Regarding genetic risk, 40 infants were classified in HR group, 75 in IR group and 55 in LR group. Two-way ANOVA did not show significant interactions between the type of milk feeding and genetic risk group on the lymphocyte subsets analysed. One-way ANOVA for milk-feeding practice alone showed that the percentage of CD4 + CD25+ cells was significantly higher in BF group than in FF group (BF, 10.92 ± 2.71; FF, 9.94 ± 2.96; p = 0.026), and absolute counts of CD4 + CD38+ cells were significantly higher in FF group than in BF group (FF, 2,881.23 ± 973.48; BF, 2,557.95 ± 977.06; p = 0.038). One-way ANOVA for genetic risk alone showed that absolute counts of NK cells were significantly higher in IR group than HR and LR groups (IR, 539.24 ± 340.63; HR, 405.01 ± 239.53; LR, 419.86 ± 262.85; p = 0.028). CONCLUSION: Lymphocyte subset profiles in the early stages of life could be modulated by milk-feeding practices and genetic risk separately. Breastfeeding might have a positive immunomodulatory effect on lymphocyte subsets in infants at risk of CD.

Coeliac Disease Case-Control Study: Has the Time Come to Explore beyond Patients at Risk?

The worldwide prevalence of asymptomatic coeliac disease (CD) is increasing, which is in part due to the routine screening of children with risk factors. Both symptomatic and asymptomatic patients with CD are at risk of long-term complications. The objective of this study was to compare the clinical characteristics of asymptomatic and symptomatic children at the time of CD diagnosis. A case-control study was conducted using data from a cohort of 4838 CD patients recruited from 73 centers across Spain between 2011 and 2017. A total of 468 asymptomatic patients (cases) were selected and matched by age and sex with 468 symptomatic patients (controls). Clinical data, including any reported symptoms, as well as serologic, genetic, and histopathologic data were collected. No significant differences were found between the two groups in most clinical variables, nor in the degree of intestinal lesion. However, the asymptomatic patients were taller (height z-score -0.12 (1.06) vs. -0.45 (1.19), p < 0.001) and were less likely to have anti transglutaminase IgA antibodies ≥ 10 times the upper normal limit (66.2% vs. 758.4%, p = 0.002). Among the 37.1% of asymptomatic patients who were not screened for CD due to the absence of risk factors, only 34% were truly asymptomatic, while the remaining 66% reported non-specific CD-related symptoms. Therefore, expanding CD screening to any child who undergoes a blood test could reduce the burden of care for some children, as many of those considered asymptomatic reported non-specific CD-related symptoms.

"Geographical distribution of risk genotypes in pediatric patients with celiac disease in Spain".

Celiac disease is strongly associated with HLA DQ, specifically with haplotypes. DRB1*03-DQA1*05:01/DQB1*02:01 (DQ2.5),DRB1*07-DQA1*02:01/DQB1*02:02 (DQ2.2), DRB1*11-DQA1*05:05/DQB1*03:01 (DQ7.5), and DRB1*04-DQA1*03:01/DQB1*03:02 (DQ8). The distribution of these risk haplotypes in patients with celiac disease is different in the geographical areas investigated. A high frequency of DRB1*07- DQA1*02:01/DQB1*02:02 (DQ2.2) and DRB1*11-DQA1*05:05/DQB1*03:01 (DQ7.5), has been described in Southern Europe. We analyzed 2102 confirmed CD cases with information on both DQB1* alelles and their distribution by geographical area in Spain. According to the presence of this haplotype in one or two chromosomes, the genotype is classified in: DQ2 homozygous, DQ2 heterozygous (cis or trans), DQ8 homozygous, DQ8/DQ2.5, DQ 2.2 homozygous and genotype known as "half DQ2". Two different patterns of risks related to CD were identified. In the Basque Country and Navarre, the Mediterranean Area (Aragon, Catalonia, Valencia, Balearic Islands, and Murcia), the South of Spain (Andalucía and Extremadura), and the Canary Islands, higher frequency of DQ2.5 trans, and more than 80% of DQ2.5/DQ2.2 homozygosis were described. The Cantabrian Coast (Cantabria, Asturias, and Galicia) and Central Areas (Castilla-León and Castilla-La Mancha) showed a higher percentage of DQ2.5/DQ2.5 homozygosis and a lower DQ2.5 in trans frequency, as in Northern Europe. Madrid has an intermediate model between the two described above. 17 cases (0.8%) did not carry any CD risk haplotypes.

Influence of environmental and genetic factors linked to celiac disease risk on infant gut colonization by Bacteroides species.

Celiac disease (CD) is an immune-mediated enteropathy involving genetic and environmental factors whose interaction might influence disease risk. The aim of this study was to determine the effects of milk-feeding practices and the HLA-DQ genotype on intestinal colonization of Bacteroides species in infants at risk of CD development. This study included 75 full-term newborns with at least one first-degree relative suffering from CD. Infants were classified according to milk-feeding practice (breast-feeding or formula feeding) and HLA-DQ genotype (high or low genetic risk). Stools were analyzed at 7 days, 1 month, and 4 months by PCR and denaturing gradient gel electrophoresis (DGGE). The Bacteroides species diversity index was higher in formula-fed infants than in breast-fed infants. Breast-fed infants showed a higher prevalence of Bacteroides uniformis at 1 and 4 months of age, while formula-fed infants had a higher prevalence of B. intestinalis at all sampling times, of B. caccae at 7 days and 4 months, and of B. plebeius at 4 months. Infants with high genetic risk showed a higher prevalence of B. vulgatus, while those with low genetic risk showed a higher prevalence of B. ovatus, B. plebeius, and B. uniformis. Among breast-fed infants, the prevalence of B. uniformis was higher in those with low genetic risk than in those with high genetic risk. Among formula-fed infants, the prevalence of B. ovatus and B. plebeius was increased in those with low genetic risk, while the prevalence of B. vulgatus was higher in those with high genetic risk. The results indicate that both the type of milk feeding and the HLA-DQ genotype influence the colonization process of Bacteroides species, and possibly the disease risk.

Breast-Milk Microbiota Linked to Celiac Disease Development in Children: A Pilot Study From the PreventCD Cohort.

Celiac disease (CeD) is an immune-mediated disorder triggered by exposure to dietary gluten proteins in genetically predisposed individuals. In addition to the host genome, the microbiome has recently been linked to CeD risk and pathogenesis. To progress in our understanding of the role of breast milk microbiota profiles in CeD, we have analyzed samples from a sub-set of mothers (n = 49) included in the PreventCD project, whose children did or did not develop CeD. The results of the microbiota data analysis indicated that neither the BMI, HLA-DQ genotype, the CeD condition nor the gluten-free diet of the mothers could explain the human milk microbiota profiles. Nevertheless, we found that origin country, the offspring's birth date and, consequently, the milk sampling date influenced the abundance and prevalence of microbes in human milk, undergoing a transition from an anaerobic to a more aerobic microbiota, including potential pathogenic species. Furthermore, certain microbial species were more abundant in milk samples from mothers whose children went on to develop CeD compared to those that remained healthy. These included increases in facultative methylotrophs such as Methylobacterium komagatae and Methylocapsa palsarum as well as in species such as Bacteroides vulgatus, that consumes fucosylated-oligosaccharides present in human milk, and other breast-abscess associated species. Theoretically, these microbiota components could be vertically transmitted from mothers-to-infants during breastfeeding, thereby influencing CeD risk.