Microbial and immune faecal determinants in infants hospitalized with COVID-19 reflect bifidobacterial dysbiosis and immature intestinal immunity.

The coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread rapidly worldwide, seriously endangering human health. Although SARS-CoV-2 had a lower impact on paediatric population, children with COVID-19 have been reported as suffering from gastrointestinal (GI) symptoms at a higher rate than adults. The aim of this work was to evaluate faeces as a source of potential biomarkers of severity in the paediatric population, with an emphasis on intestinal microbiota and faecal immune mediators, trying to identify possible dysbiosis and immune intestinal dysfunction associated with the risk of hospitalization. This study involved 19 patients with COVID-19 under 24 months of age hospitalized during the pandemic at 6 different hospitals in Spain, and it included a comparable age-matched healthy control group (n = 18). Patients and controls were stratified according to their age in two groups: newborns or young infants (from 0 to 3 months old) and toddlers (infants from 6 to 24 months old). To characterize microbial intestinal communities, sequencing with Illumina technology of total 16S rDNA amplicons and internal transcribed spacer (ITS) amplicons of bifidobacteria were used. Faecal calprotectin (FC) and a range of human cytokines, chemokines, and growth factors were measured in faecal samples using ELISA and a multiplex system. Significant reduction in the abundance of sequences belonging to the phylum Actinobacteria was found in those infants with COVID-19, as well as in the Bifidobacteriaceae family. A different pattern of bifidobacteria was observed in patients, mainly represented by lower percentages of Bifidobacterium breve, as compared with controls. In the group of hospitalized young infants, FC was almost absent compared to age-matched healthy controls. A lower prevalence in faecal excretion of immune factors in these infected patients was also observed. CONCLUSION:  Hospitalized infants with COVID-19 were depleted in some gut bacteria, such as bifidobacteria, in particular Bifidobacterium breve, which is crucial for the proper establishment of a functional intestinal microbiota, and important for the development of a competent immune system. Our results point to a possible immature immune system at intestine level in young infants infected by SARS-CoV2 requiring hospitalization. WHAT IS KNOWN: • Although SARS-CoV-2 had a lower impact on paediatric population, children with COVID-19 have been reported as suffering from gastrointestinal symptoms at a higher rate than adults. • Changes in microbial composition have been described in COVID-19 adult patients, although studies in children are limited. WHAT IS NEW: • The first evidence that hospitalized infants with COVID-19 during the pandemic had a depletion in bifidobacteria, particularly in Bifidobacterium breve, beneficial gut bacteria in infancy that are crucial for the proper establishment of a competent immune system. • In young infants (under 3 months of age) hospitalized with SARS-CoV2 infection, the aberrant bifidobacterial profile appears to overlap with a poor intestinal immune development as seen by calprotectin and the trend of immunological factors excreted in faeces.

The use of amino acid formulas in pediatric patients with allergy to cow's milk proteins: Recommendations from a group of experts.

One of the most common food allergies in children is cow's milk allergy (CMA). In breast-fed infants with CMA, the mother is encouraged to avoid dairy products. If this is not possible, or in formula fed infants, use of hypoallergenic replacement formulas such as extensively hydrolyzed formulas (EHF) is recommended. However, in ∼5% of patients EHFs are not tolerated and/or allergy symptoms can persist. When EHFs are ineffective and in severe forms of CMA, amino acid-based formulas (AAF) should be considered. Six pediatric gastroenterologists with extensive experience in food allergy management reviewed scientific publications and international clinical practice guidelines to provide practical recommendations on AAF. The guidelines reviewed had discrepancies and ambiguities around the specific indications for using formulas as a milk substitute. The panel recommends AAFs as the first therapeutic option in anaphylaxis due to CMA, in acute and chronic severe food protein-induced enterocolitis syndrome, in CMA associated with multiple food allergy, and in cases of eosinophilic esophagitis not responding to an extended exclusion diet or not eating solids. The main benefit of AAF is its absence of residual allergenicity, making it a safe treatment option in severe CMA patients who do not tolerate or respond to an EHF.

Clinical utility of urinary gluten immunogenic peptides in the follow-up of patients with coeliac disease.

BACKGROUND: Gluten-free diet (GFD) is the only treatment for patients with coeliac disease (CD) and its compliance should be monitored to avoid cumulative damage. AIMS: To analyse gluten exposures of coeliac patients on GFD for at least 24 months using different monitoring tools and its impact on duodenal histology at 12-month follow-up and evaluate the interval of determination of urinary gluten immunogenic peptides (u-GIP) for the monitoring of GFD adherence. METHODS: Ninety-four patients with CD on a GFD for at least 24 months were prospectively included. Symptoms, serology, CDAT questionnaire, and u-GIP (three samples/visit) were analysed at inclusion, 3, 6, and 12 months. Duodenal biopsy was performed at inclusion and 12 months. RESULTS: At inclusion, 25.8% presented duodenal mucosal damage; at 12 months, this percentage reduced by half. This histological improvement was indicated by a reduction in u-GIP but did not correlate with the remaining tools. The determination of u-GIP detected a higher number of transgressions than serology, regardless of histological evolution type. The presence of >4 u-GIP-positive samples out of 12 collected during 12 months predicted histological lesion with a specificity of 93%. Most patients (94%) with negative u-GIP in ≥2 follow-up visits showed the absence of histological lesions (p < 0.05). CONCLUSION: This study suggests that the frequency of recurrent gluten exposures, according to serial determination of u-GIP, could be related to the persistence of villous atrophy and that a more regular follow-up every 6 months, instead of annually, provides more useful data about the adequate adherence to GFD and mucosal healing.

Negative predictive value of the repeated absence of gluten immunogenic peptides in the urine of treated celiac patients in predicting mucosal healing: new proposals for follow-up in celiac disease.

BACKGROUND: The treatment of celiac disease (CD) is a lifelong gluten-free diet (GFD). The current methods for monitoring GFD conformance, such as a dietary questionnaire or serology tests, may be inaccurate in detecting dietary transgressions, and duodenal biopsies are invasive, expensive, and not a routine monitoring technique. OBJECTIVES: Our aim was to determine the clinical usefulness of urine gluten immunogenic peptides (GIP) as a biomarker monitoring GFD adherence in celiac patients and to evaluate the concordance of the results with the degree of mucosal damage. METHODS: A prospective observational study was conducted involving 22 de novo CD patients, 77 celiac patients consuming a GFD, and 13 nonceliac subjects. On 3 d of the week, urine samples were collected and the GIP concentrations were tested. Simultaneously, anti-tissue transglutaminase antibodies, questionnaire results, clinical manifestations, and histological findings were analyzed. RESULTS: Approximately 24% (18 of 76) of the celiac patients consuming a GFD exhibited Marsh II-III mucosal damage. Among this population, 94% (17 of 18) had detectable urine GIP; however, between 60% and 80% were asymptomatic and exhibited negative serology and appropriate GFD adherence based on the questionnaire. In contrast, 97% (31 of 32) of the celiac patients without duodenal damage had no detectable GIP. These results demonstrated the high sensitivity (94%) and negative predictive value (97%) of GIP measurements in relation to duodenal biopsy findings. In the de novo CD-diagnosed cohort, 82% (18 of 22) of patients had measurable amounts of GIP in the urine. CONCLUSIONS: Determining GIP concentrations in several urine samples may be an especially convenient approach to assess recent gluten exposure in celiac patients and appears to accurately predict the absence of histological lesions. The introduction of GIP testing as an assessment technique for GFD adherence may help in ascertaining dietary compliance and to target the most suitable intervention during follow-up.

Prospective longitudinal study: use of faecal gluten immunogenic peptides to monitor children diagnosed with coeliac disease during transition to a gluten-free diet.

BACKGROUND: Treatment for coeliac disease is a lifelong strict gluten-free diet. Although guidelines recommend regular follow-up with dietary interviews and coeliac serology, these methods may be inaccurate. AIM: To evaluate the usefulness of faecal gluten immunogenic peptides to support the diagnosis and to determine the adherence to the gluten-free diet in coeliac children. METHODS: Multicentre prospective observational study including 64 coeliac children. Faecal gluten peptides, and tissue transglutaminase and deamidated gliadin peptide antibodies were analyzed at diagnosis, and 6, 12 and 24 months thereafter. Gluten consumption was estimated from gluten peptide levels. RESULTS: Most children (97%) had detectable gluten peptides at diagnosis. On a gluten-free diet, the rate of gluten peptides increased from 13% at 6 months to 25% at 24 months. Mean estimated gluten exposure dropped from 5543 mg/d at diagnosis to 144 mg/d at 6 months, then increased to 606 mg/d by 24 months. In contrast, deamidated gliadin peptide antibodies normalised and only 20% had elevated tissue transglutaminase antibody by 24 months. The elevation of tissue transglutaminase antibody was more prolonged in patients with detectable gluten peptides (P < 0.05). Nevertheless, absolute levels of tissue transglutaminase antibody had low sensitivity to identify patients with detectable gluten peptides (P > 0.1). Dietitian assessment was only moderately correlated with gluten peptide detection (κ = 0.5). CONCLUSIONS: Faecal gluten peptides testing may guide treatment of coeliac disease prior to diagnosis and during the assessment diet adherence. Further studies could determine if early identification of gluten exposure reduces the need for expensive/invasive investigations for non-responsive coeliac disease. ClinicalTrials.gov Number: NCT02711397.

Food Protein-induced Enterocolitis Syndrome: Data From a Multicenter Retrospective Study in Spain.

OBJECTIVE: The aim of the study was to describe clinical, epidemiological, and management characteristics of food protein-induced enterocolitis syndrome (FPIES) cases in Spain. PATIENTS AND METHODS: Multicenter observational retrospective study. FPIES cases diagnosed in specialized units in Spain over 12 months in 2017 (January-December) according to the recently published international diagnostic criteria were included. RESULTS: One hundred twenty patients (53.3% boys) were included. The majority were acute cases (111) with mild-to-moderate severity (76.7%). Triggering foods were cow's milk (48/120), fish (38), egg (13), rice (12), and soy (1). The majority (84.2%) of the patients had FPIES to 1 food only. In addition to vomiting (100%), pallor (89.2%), and altered behavior (88.3%) were most frequently observed in acute forms. On the contrary, diarrhea (70%), abdominal distension (33.3%), and blood in stools (44.4%) were more frequently observed in chronic cases. Oral challenge was performed in 18.9% of the acute forms compared to 44.4% of the chronic forms. The most common treatment was intravenous fluids followed by ondansetron. Corticosteroids were used in 6 patients (5 with acute symptoms and 1 chronic). Seven patients were treated with antibiotics for suspicion of infection. Most cases of cow's milk FPIES were treated with extensively hydrolyzed formulas (69.8%). CONCLUSIONS: FPIES is not uncommon in our units. Unlike other published series, fish and egg are important triggers in our country. A greater knowledge and diffusion of the international consensus criteria will allow a better characterization of the cases and a standardization of their management.

Corrigendum: Fecal Gluten Peptides Reveal Limitations of Serological Tests and Food Questionnaires for Monitoring Gluten-Free Diet in Celiac Disease Patients.

This corrects the article DOI: 10.1038/ajg.2016.439.

Fecal Gluten Peptides Reveal Limitations of Serological Tests and Food Questionnaires for Monitoring Gluten-Free Diet in Celiac Disease Patients.

OBJECTIVES: Treatment for celiac disease (CD) is a lifelong strict gluten-free diet (GFD). Patients should be followed-up with dietary interviews and serology as CD markers to ensure adherence to the diet. However, none of these methods offer an accurate measure of dietary compliance. Our aim was to evaluate the measurement of gluten immunogenic peptides (GIP) in stools as a marker of GFD adherence in CD patients and compare it with traditional methods of GFD monitoring. METHODS: We performed a prospective, nonrandomized, multicenter study including 188 CD patients on GFD and 84 healthy controls. Subjects were given a dietary questionnaire and fecal GIP quantified by enzyme-linked immunosorbent assay (ELISA). Serological anti-tissue transglutaminase (anti-tTG) IgA and anti-deamidated gliadin peptide (anti-DGP) IgA antibodies were measured simultaneously. RESULTS: Of the 188 celiac patients, 56 (29.8%) had detectable GIP levels in stools. There was significant association between age and GIP in stools that revealed increasing dietary transgressions with advancing age (39.2% in subjects ≥13 years old) and with gender in certain age groups (60% in men ≥13 years old). No association was found between fecal GIP and dietary questionnaire or anti-tTG antibodies. However, association was detected between GIP and anti-DGP antibodies, although 46 of the 53 GIP stool-positive patients were negative for anti-DGP. CONCLUSIONS: Detection of gluten peptides in stools reveals limitations of traditional methods for monitoring GFD in celiac patients. The GIP ELISA enables direct and quantitative assessment of gluten exposure early after ingestion and could aid in the diagnosis and clinical management of nonresponsive CD and refractory CD. Trial registration number NCT02711397.

Prebiotic effect during the first year of life in healthy infants fed formula containing GOS as the only prebiotic: a multicentre, randomised, double-blind and placebo-controlled trial.

PURPOSE: Currently, there is no consensus concerning the possible beneficial colonic and systemic effects of prebiotic-containing infant formula. This study assesses whether the feeding of a galactooligosaccharides (GOS)-containing infant formula (0.44 g/dl of GOS) and the subsequent feeding of a GOS-containing follow-on formula (0.50 g/dl of GOS) have a prebiotic effect on intestinal microbiota that helps to decrease infections and allergy manifestations in healthy infants during the first year of life. METHODS: A multicentre, randomised, double-blind and placebo-controlled trial was carried out on 365 healthy term infants enrolled before 8 weeks of age and randomly assigned to a formula with or without GOS, until 12 months of age. The incidence of infections and allergy manifestations, the antibiotics prescribed and faecal characteristics were recorded up to 12 months of age, while faecal samples were collected up to 4 months for the measurement of secretory immunoglobulin A, short-chain fatty acids and microbiota. RESULTS: A prebiotic effect on the faecal analysis was observed at 4 months of life. The GOS group showed a lower faecal pH (P = 0.019), a lower decreasing trend in secretory immunoglobulin A (P = 0.078), lower butyric acid concentration (P = 0.040) and an increase in Bifidobacterium counts (P = 0.010). Changes in faecal characteristics involved greater frequency (P < 0.001) and softer consistency (P < 0.05). The incidence of infections or allergic manifestations during the first year of life was similar in both groups, with no statistical differences (P > 0.05). CONCLUSIONS: The feeding of GOS-containing infant formula produced a definite prebiotic effect consisting of changes in faecal composition and microbiota, and in faecal consistency and the frequency of defaecation. No changes in the incidence of infection or allergic manifestation during the first year of life were observed.

Spanish national registry of celiac disease: incidence and clinical presentation.

OBJECTIVES: The aim of this study was to assess the incidence and clinical pattern of celiac disease (CD) presently diagnosed in Spanish children. METHODS: A prospective, multicenter, nationwide registry of new cases of CD in children <15 years was conducted from June 1, 2006 to May 31, 2007. The parameters studied were age at diagnosis, sex, clinical symptoms, associated diseases, nutritional status, CD serology, histological lesions, and HLA-DQ2/-DQ8. The crude incidence rate of CD was calculated as new cases per 1000 live births and as new cases per 100,000 person-years <15 years of age. RESULTS: A total of 974 new cases of CD were included. The median age at diagnosis was 2.3 years; 39.5% of CD diagnoses occurred in the first 2 years, 42% between 2 and 6, and 18.4% from 6 to 15. Total number of cases in each age group was 385, 409, and 180, respectively. Regarding clinical presentation 70.9% showed classical symptoms, 21.9% were nonclassical, and 7% were asymptomatic. A total of 95.7% of 931, 94.7% of 611, and 86.7% of 651 children tested positive, respectively, for immunoglobulin A (IgA) anti-transglutaminase type 2 antibodies, IgA endomysial antibodies, and IgA anti-gliadin antibodies. Villous atrophy was observed in 92.4% and increased intraepithelial lymphocytes with crypt hyperplasia in 3.3%. Of the children, 55% had normal growth, and 3.4% were overweight. The HLA phenotype was DQ2: 88.3%, DQ2/DQ8: 8.4%, and DQ8: 2.3%. The incidence rate was 7.9 cases of CD per 1000 live births and 54 cases per 100,000 person-years. CONCLUSIONS: In Spain, the most frequent clinical presentation of CD is the classical form, mainly diagnosed during the first 2 years of life. The observed incidence of CD in Spanish children is much higher than the present CD incidence rates observed in other European countries.