Faecal lipid profile as a new marker of fat maldigestion, malabsorption and microbiota.

BACKGROUND: Fat malabsorption in children with cystic fibrosis (CF) leads to poor nutritional status and altered colonic microbiota. This study aimed at establishing the faecal lipid profile in children with CF, and exploring associations between the faecal lipidome and microbiota. METHODS: Cross-sectional observational study with children with CF and an age-matched control group. Faecal lipidome was analysed by UHLC-HRMS and microbiota profiling by 16S rRNA amplicon sequencing. RESULTS: Among 234 identified lipid species, five lipidome clusters (LC) were obtained with significant differences in triacylglycerols (TG), diacylglycerols (DG), monoacylglycerols (MG) and fatty-acids (FA): LC1 subjects with good digestion and absorption: low TG and low MG and FA; LC2 good digestion and poor absorption: low TG and high MG and FA; LC3 Mild digestion and poor absorption: intermediate TG and high MG and FA; LC4 poor digestion and absorption: high TG and high MG and FA; LC5 outliers. Bacteroidota and Verrucomicrobiota decreased over LC1-LC4, while Proteobacteria increased. Nutritional status indicators were significantly higher in LC1 and decreased over LC2-LC4. CONCLUSION: Assessing faecal lipidome may be relevant to determine how dietary lipids are digested and absorbed. This new evidence might be a method to support targeted nutritional interventions towards reverting fat maldigestion or malabsorption. IMPACT: Lipidomic analysis enabled the identification of the lipid species related to maldigestion (triglycerides) or malabsorption (monoglycerides and fatty acids). Children with cystic fibrosis can be grouped depending on the faecal lipidome profile related to dietary fat maldigestion or malabsorption. The lipidome profile in faeces is related to the composition of microbiota and nutritional status indicators.

ESPEN-ESPGHAN-ECFS guideline on nutrition care for cystic fibrosis.

BACKGROUND: Nutritional status is paramount in Cystic Fibrosis (CF) and is directly correlated with morbidity and mortality. The first ESPEN-ESPGHAN-ECFS guidelines on nutrition care for infants, children, and adults with CF were published in 2016. An update to these guidelines is presented. METHODS: The study was developed by an international multidisciplinary working group in accordance with officially accepted standards. Literature since 2016 was reviewed, PICO questions were discussed and the GRADE system was utilized. Statements were discussed and submitted for on-line voting by the Working Group and by all ESPEN members. RESULTS: The Working Group updated the nutritional guidelines including assessment and management at all ages. Supplementation of vitamins and pancreatic enzymes remains largely the same. There are expanded chapters on pregnancy, CF-related liver disease, and CF-related diabetes, bone disease, nutritional and mineral supplements, and probiotics. There are new chapters on nutrition with highly effective modulator therapies and nutrition after organ transplantation.

Long-term evaluation of faecal calprotectin levels in a European cohort of children with cystic fibrosis.

OBJECTIVE: Intestinal inflammation with contradictory data on faecal calprotectin (fCP) levels is documented in patients with cystic fibrosis (CF). The aim of this study was to longitudinally evaluate fCP in a cohort of children with CF and their relationship with clinical variables. DESIGN: Prospective observational study to assess evolution of fCP levels, primary aimed at improving fat absorption. Along 1.5 years of follow-up (November 2016-May 2018) with four study visits pertaining to a pilot study (two of four) and to a clinical trial (two of four), the study outcomes were measured. SETTING: Six European CF centres in the context of MyCyFAPP Project. SUBJECTS: Children with CF and pancreatic insufficiency (2-18 years old). MAIN OUTCOME MEASUREMENTS: fCP levels, pulmonary function (percentage of forced expiratory volume in 1 s (FEV1%)) and coefficient of fat absorption (CFA). Additionally, in the last two visits, gastrointestinal (GI) symptoms were evaluated through the PedsQL-GI Questionnaire. Linear mixed regression models were applied to assess association between fCP and FEV1, CFA and GI symptoms. RESULTS: Twenty-nine children with CF and pancreatic insufficiency were included. fCP levels were inversely associated with total modified specific PedsQL-GI score (p=0.04) and positively associated with diarrhoea (p=0.03), but not with CFA. Along the four study visits, fCP significantly increased (from 62 to 256 µg/g) and pulmonary function decreased (from 97% to 87%), with a significant inverse association between the two study outcomes (p<0.001). CONCLUSIONS: In children with CF, fCP levels are inversely associated with pulmonary function and thus the specificity of fCP as a marker of intestinal inflammation in paediatric patients with CF warrants further investigation.

Effect of beta-glucan supplementation on cystic fibrosis colonic microbiota: an in vitro study.

BACKGROUND: Children with cystic fibrosis (CF) present with gut dysbiosis, and current evidence impedes robust recommendations on the use of prebiotics. This study aimed at establishing the prebiotic potential of a commercial beta-glucan on the in vitro colonic microbiota of a child with CF compared to a healthy counterpart (H). METHODS: A dynamic simulator of colonic fermentation (twin-SHIME® model) was set up including the simulation of the proximal (PC) and distal colon (DC) of the CF and the H subjects by colonizing the bioreactors with faecal microbiota. During two weeks the system was supplied with the beta-glucan. At baseline, during treatment and post-treatment, microbiota composition was profiled by 16 S rRNA and short-chain fatty acids (SCFA) production was determined by GS-MS. RESULTS: At baseline, Faecalibacterium, was higher in CF' DC than in the H, along higher Acidaminococcus and less Megasphaera and Sutterella. Beta-glucan supplementation induced increased microbiota richness and diversity in both subjects during the treatment. At genus level, Pseudomonas and Veillonella decreased, while Akkermansia and Faecalibacterium increased significantly in CF. CONCLUSION: The supplementation with beta-glucan suggests positive results on CF colonic microbiota in the in vitro context, encouraging further research in the in vivo setting. IMPACT: Current evidence supports assessing the effect of prebiotics on modifying cystic fibrosis microbiota. The effect of beta-glucan supplementation was evaluated in a controlled dynamic in vitro colonic ecosystem. Beta-glucan supplement improved diversity in cystic fibrosis colonic microbiota. The treatment showed increased abundance of Faecalibacterium and Akkermansia in cystic fibrosis. New evidence supports the use of prebiotics in future clinical studies.

Association between Dietary Intake and Faecal Microbiota in Children with Cystic Fibrosis.

A "high-fat, high-energy diet" is commonly recommended for children with cystic fibrosis (CF), leading to negative consequences on dietary patterns that could contribute to altered colonic microbiota. The aim of this study was to assess dietary intake and to identify possible associations with the composition of faecal microbiota in a cohort of children with CF. A cross-sectional observational study was conducted, including a 3-day food record simultaneously with the collection of faecal samples. The results showed a high fat intake (43.9% of total energy intake) and a mean dietary fibre intake of 10.6 g/day. The faecal microbiota was characterised at the phylum level as 54.5% Firmicutes and revealed an altered proportion between Proteobacteria (32%) and Bacteroidota (2.2%). Significant associations were found, including a negative association between protein, meat, and fish intake and Bifidobacterium, a positive association between lipids and Escherichia/Shigella and Streptococcus, a negative association between carbohydrates and Veillonella and Klebsiella, and a positive association between total dietary fibre and Bacteroides and Roseburia. The results reveal that a "high-fat, high-energy" diet does not satisfy dietary fibre intake from healthy food sources in children with CF. Further interventional studies are encouraged to explore the potential of shifting to a high-fibre or standard healthy diet to improve colonic microbiota.

Encephalopathy in short bowel syndrome: a diagnostic challenge.

A 15-year-old boy was admitted to the hospital due to ataxia, drowsiness and bradypsychia. He was known to have a short bowel syndrome Initial venous blood gases revealed a metabolic acidosis with a high anion gap of 24 mmol/L and normal L-lactate. He improved with fasting and fluids and was discharged with oral metronidazole. 2 weeks later he was admitted again with similar symptoms. A specific study of D-Lactic acidosis was carried out, confirming the diagnosis. D-lactic acidosis is an uncommon complication of short bowel syndrome. It occurs as a consequence of the metabolism of unabsorbed carbohydrates. The symptoms are mainly neurological. Limiting the dietary carbohydrates is useful to avoid recurrences. Poorly absorbable antibiotics are used but with varying results. Surgery may be an option if medical treatment fails. Probiotics might be useful to avoid symthoms recurrence.

How macronutrients and pancreatic enzyme supplements dose variability affect fat, protein and starch absorption in children with cystic fibrosis.

BACKGROUND: low evidence on the dose of enzymatic supplements used in pancreatic enzyme replacement therapy (PERT) is available. AIM: assessing if fat, protein and starch absorption could be related to the dose of the enzymatic supplement, the intra-patient variability in the dose and macronutrient intake. METHODS: Four-day food records and 3-day faecal samples were prospectively collected in 69 children with cystic fibrosis. Pearson correlations between enzyme dose and macronutrient absorption, and beta regression models were applied to explain the results. RESULTS: the supply of protease units per protein intake (PU/g protein) in relation to lipase units per fat intake (LU/g fat) was low and the intra-patient variability in the dose of enzymes was ±1331 LU/g fat. Fat and starch absorption was >90% while for protein it was 81.5%. The coefficient of fat absorption was associated with an interaction between the dose of LU/g fat and its variability among different days. Lipid and protein intake were also determinants of the coefficient of fat absorption. CONCLUSION: the dose of PERT should be re-adjusted to the amount of dietary fat of every meal (constant LU/g fat) to minimize variability and increase fat absorption. Also, the supply of protease should be increased to prevent from protein malabsorption.

Correlation of Anti-Tissue Transglutaminase Antibodies With the Mucosal Changes and IgA Status of Children With Celiac Disease.

OBJECTIVES: The objective of this study was to assess the association between serological markers and changes of the intestinal mucosa in children with celiac disease (CD). METHODS: Clinical data from CD patients under 15 years old were collected from the participating centers in an on-line multicenter nationwide observational Spanish registry called REPAC-2 (2011-2017). Correlation between anti-tissue transglutaminase antibodies (t-TGA) levels and other variables, including mucosal damage and clinical findings (symptoms, age, and gender), was assessed. RESULTS: A total of 2955 of 4838 patients had t-TGA and a small bowel biopsy (SBB) performed for CD diagnosis. A total of 1931 (66.2%) patients with normal IgA values had a Marsh 3b-c lesion and 1892 (64.9%) had t-TGA Immunoglobulin A (IgA) ≥ 10 times upper limit of normal (ULN). There is a statistically significant association between t-TGA IgA levels and the degree of mucosal damage ( P < 0.001), the higher the t-TGA IgA levels the more severe the mucosal damage. Those patients who reported symptoms had more severe mucosal damage ( P = 0.001). On the contrary, there was a negative association between age and changes of the intestinal mucosa ( P < 0.001). No association was found with gender. Regarding the IgA-deficient patients, 47.4% (18 cases) had t-TGA Immunoglobulin A (IgA) ≥ 10 times ULN and a Marsh 3b-c lesion was observed in 68.4% (26 patients). No statistical relation was found between t-TGA IgG levels and the changes of the intestinal mucosa, neither a relation with age, gender, or symptoms. CONCLUSIONS: There is a positive correlation between t-TGA IgA levels and the severity of changes of the intestinal mucosa. Such correlation was not found in IgA-deficient patients who had positive t-TGA IgG serology. The results in this group of patients support the European Society for Paediatric Gastroenterology, Hepatology, and Nutrition recommendations about the need of performing a SBB in IgA-deficient individuals despite high t-TGA IgG levels.

Intestinal anti-tissue transglutaminase IgA deposits as a complementary method for the diagnostic evaluation of celiac disease in patients with low-grade histological lesions.

Evaluating the usefulness of intestinal anti-transglutaminase IgA (anti-TG2 IgA) deposits detection as a complementary or decision-supporting tool in the diagnosis of celiac disease (CD) in patients with low degree of enteropathy. Small intestinal biopsies (SIB) were performed from 2008 to 2017 in patients on suspicion of CD (positive CD serology and/or symptoms) referred to our Pediatric Gastroenterology Unit. We determined anti-TG2 IgA deposits by using double immunofluorescence in all the patients in whom Marsh 0 or Marsh 1 was detected in the conventional histological study and in a random selection of patients with clearly positive serology and histological Marsh 2-3 lesion. Seventy-five pediatric patients were split into three groups according to the final diagnosis: (i) 13 children with a Marsh 0 or 1, negative CD serology and final non-CD diagnosis; none presented intestinal anti-TG2 IgA deposits; (ii) 15 potential CD cases (Marsh 0 or 1 and CD-associated antibodies), detecting anti-TG2 IgA deposits in 12; on follow-up, another biopsy performed in 11/15 showed villi atrophy in seven and a Marsh 2 lesion in two of them, patients being finally diagnosed as CD cases; and (iii) 47 children with Marsh 2-3 histological lesion and final CD diagnosis; all of them had intestinal anti-TG2 IgA deposits. Anti-TG2 deposits are a useful complementary tool for CD diagnosis in pediatric population with digestive pathologies suggestive of CD. It is especially helpful in those with low-grade lesion, in which anti-TG2 deposits are predictive of the development of more severe lesions on follow-up.

Change in Nutrient and Dietary Intake in European Children with Cystic Fibrosis after a 6-Month Intervention with a Self-Management mHealth Tool.

Cystic Fibrosis (CF) is a life-long genetic disease, causing increased energy needs and a healthy diet with a specific nutrient distribution. Nutritional status is an indicator of disease prognosis and survival. This study aimed at assessing the effectiveness of a self-management mobile app in supporting patients with CF to achieve the dietary goals set by the CF nutrition guidelines. A clinical trial was conducted in pancreatic insufficient children with CF, followed in six European CF centres, where the self-management app developed within the MyCyFAPP project was used for six months. To assess secondary outcomes, three-day food records were compiled in the app at baseline and after 3 and 6 months of use. Eighty-four subjects (mean 7.8 years old) were enrolled. Compared to baseline, macronutrient distribution better approximated the guidelines, with protein and lipid increasing by 1.0 and 2.1% of the total energy intake, respectively, by the end of the study. Consequently, carbohydrate intake of the total energy intake decreased significantly (-2.9%), along with simple carbohydrate intake (-2.4%). Regarding food groups, a decrease in ultra-processed foods was documented, with a concomitant increase in meat and dairy. The use of a self-management mobile app to self-monitor dietary intake could become a useful tool to achieve adherence to guideline recommendations, if validated during a longer period of time or against a control group.

Drugs in Focus: Proton Pump Inhibitors.

ABSTRACT: Proton pump inhibitors (PPIs) are amongst the most commonly prescribed drugs in infants and children with the last decades witnessing a dramatic rise in their utilization. Although PPIs are clearly effective when used appropriately and have been regarded as safe drugs, there is growing evidence regarding their potential adverse effects. Although, largely based on adult data it is clear that many of these are also relevant to pediatrics. PPI use potentially affects gastrointestinal microbiota composition and function, decreases defence against pathogens resulting in increased risk for infections, interferes with absorption of minerals and vitamins leading to specific deficiencies and increased risk for bone fractures as well as interferes with protein digestion resulting in increased risk of sensitization to allergens and development of allergic diseases and eosinophilic esophagitis. An association with gastric, liver and pancreatic cancer has also been inferred from adult data but is tenuous and causation is not proven. Overall, evidence for these adverse events is patchy and not always compelling. Overall, the use of PPIs, for selected indications with a good evidence base, has significant potential benefit but carries more caution in infants and children. Pediatricians should be aware of the concerns regarding the potential adverse events associated with their use.

Association between faecal pH and fat absorption in children with cystic fibrosis on a controlled diet and enzyme supplements dose.

BACKGROUND: Despite treatment with pancreatic enzyme replacement therapy (PERT), patients with cystic fibrosis (CF) can still suffer from fat malabsorption. A cause could be low intestinal pH disabling PERT. The aim of this study was to assess the association between faecal pH (as intestinal pH surrogate) and coefficient of fat absorption (CFA). Additionally, faecal free fatty acids (FFAs) were quantified to determine the amount of digested, but unabsorbed fat. METHODS: In a 24-h pilot study, CF patients followed a standardised diet with fixed PERT doses, corresponding to theoretical optimal doses determined by an in vitro digestion model. Study variables were faecal pH, fat and FFA excretion, CFA and transit time. Linear mixed regression models were applied to explore associations. RESULTS: In 43 patients, median (1st, 3rd quartile) faecal pH and CFA were 6.1% (5.8, 6.4) and 90% (84, 94), and they were positively associated (p < 0.001). An inverse relationship was found between faecal pH and total fat excretion (p < 0.01), as well as total FFA (p = 0.048). Higher faecal pH was associated with longer intestinal transit time (p = 0.049) and the use of proton pump inhibitors (p = 0.009). CONCLUSIONS: Although the clinical significance of faecal pH is not fully defined, its usefulness as a surrogate biomarker for intestinal pH should be further explored. IMPACT: Faecal pH is a physiological parameter that may be related to intestinal pH and may provide important physiopathological information on CF-related pancreatic insufficiency. Faecal pH is correlated with fat absorption, and this may explain why pancreatic enzyme replacement therapy is not effective in all patients with malabsorption related to CF. Use of proton pump inhibitors is associated to higher values of faecal pH. Faecal pH could be used as a surrogate biomarker to routinely monitor the efficacy of pancreatic enzyme replacement therapy in clinical practice. Strategies to increase intestinal pH in children with cystic fibrosis should be targeted.

Screening-detected positive serology for celiac disease: a real clinical challenge.

According to European Society for Paediatric Gastroenterology, Hepatology, and Nutrition 2020 criteria for celiac disease diagnosis, the small bowel biopsy (SBB) can be omitted in selected circumstances, even in asymptomatic patients. Hence, we have conducted a retrospective study to identify the histological findings of the asymptomatic patients with antitransglutaminase IgA antibodies 10 times above the upper limit of normal and positive antiendomisium antibodies; 5/24 patients fulfilling these criteria had, however, a nonconclusive SBB and were diagnosed with potential celiac disease. The nonbiopsy approach in these cases needs to be carefully evaluated and the risk of overdiagnosis pondered as the management and evolution of potential celiac disease cases is still a matter of study.

Clinical evaluation of an evidence-based method based on food characteristics to adjust pancreatic enzyme supplements dose in cystic fibrosis.

BACKGROUND: Patients with cystic fibrosis (CF) and pancreatic insufficiency need pancreatic enzyme replacement therapy (PERT) for dietary lipids digestion. There is limited evidence for recommending the adequate PERT dose for every meal, and controlling steatorrhea remains a challenge. This study aimed to evaluate a new PERT dosing method supported by a self-management mobile-app. METHODS: Children with CF recruited from 6 European centres were instructed to use the app, including an algorithm for optimal PERT dosing based on in vitro digestion studies for every type of food. At baseline, a 24h self-selected diet was registered in the app, and usual PERT doses were taken by the patient. After 1 month, the same diet was followed, but PERT doses were indicated by the app. Change in faecal fat and coefficient of fat absorption (CFA) were determined. RESULTS: 58 patients (median age 8.1 years) participated. Baseline fat absorption was high: median CFA 96.9%, median 2.4g faecal fat). After intervention CFA did not significantly change, but range of PERT doses was reduced: interquartile ranges narrowing from 1447-3070 at baseline to 1783-2495 LU/g fat when using the app. Patients with a low baseline fat absorption (CFA<90%, n=12) experienced significant improvement in CFA after adhering to the recommended PERT dose (from 86.3 to 94.0%, p=0.031). CONCLUSION: the use of a novel evidence-based PERT dosing method, based on in vitro fat digestion studies incorporating food characteristics, was effective in increasing CFA in patients with poor baseline fat absorption and could safely be implemented in clinical practice.

Analysis of gluten immunogenic peptides in feces to assess adherence to the gluten-free diet in pediatric celiac patients.

PURPOSE: In celiac disease (CD) there is a need for precise and non-invasive tools to assess dietary compliance to the gluten-free diet (GFD). Our aim is to evaluate the efficacy of the detection of gluten immunogenic peptides (GIP) in feces, to monitor in real life, the adherence to GFD in pediatric patients with CD. METHODS: A cross-sectional, prospective study was conducted. Fecal samples from CD children were analyzed by a rapid immunochromatographic (IC) test and by an ELISA method, both based on the antigliadin 33-mer monoclonal antibody. RESULTS: Group 1 comprises 43 children on a GFD. According to the food records (FR), 39/43 patients were compliant with the GFD and gluten consumption was recorded in 4. GIP were detected in 15/43 individuals by the ELISA method and also in 7 by IC strips. Group 2: comprise 18 children at CD diagnosis; GIP levels decreased over time (p < 0.001) in a non-linear way (p = 0.028) after starting a GFD and were below the detection limit on the third day in most individuals. CONCLUSION: GIP were detected, both by ELISA and by IC strips, in CD patients on a GFD, in which no consumption of gluten had been registered on the FR, confirming GIP detection to be superior to FR discovering involuntary transgressions. Despite a positive correlation between the amount of gluten intake and the concentration of GIP in feces, the interindividual variations observed suggest gastrointestinal factors influencing GIP recovery need to be further investigated.

Fecal calprotectin in healthy children aged 4-16 years.

Reference values of fecal calprotectin (fCP) have not been convincingly established in children. We aimed to investigate fCP concentrations in a larger population of healthy children aged 4-16 years to analyze more in depth the behavior of fCP in this age range and to determine if cut-off levels could be conclusively recommended. A prospective study was conducted to investigate fCP concentrations of healthy children aged 4-16 years. In 212 healthy children, the median and 95th percentile for fCP were 18.8 mg/kg and 104.5 mg/kg, respectively. We found a statistically significant association between the 95th percentile of fCP concentrations and age (p < 0.001). We propose a nomogram to facilitate the interpretation of fCP results in children aged 4-16 years. Further studies are required to validate the proposed values in clinical practice.

Safety of Thiopurine Use in Paediatric Gastrointestinal Disease.

Thiopurines, alone or in combination with other agents, have a pivotal role in the treatment of specific gastrointestinal and hepatological disorders. In inflammatory bowel disease and autoimmune hepatitis thiopurines have proven their value as steroid sparing agents for the maintenance of remission and may be considered for preventing postoperative Crohn disease recurrence where there is moderate risk of this occurring. Their use with infliximab therapy reduces antibody formation and increases biologic drug levels. The routine clinical use of thiopurines has, however, been questioned due to a number of potential adverse effects. The aim of this article is to provide information regarding the use, and in particular, safety of these agents in clinical practice in the light of such potentially severe, albeit rare, effects.

[Rational application of the new European Society for Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) 2020 criteria for the diagnosis of coeliac disease]. / Aplicación racional de los nuevos criterios de la European Society for Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) 2020 para el diagnóstico de la enfermedad celíaca.

Coeliac disease is a systemic immune-mediated disorder triggered by the ingestion of gluten, which is given in genetically predisposed subjects. It manifests with a wide variety of clinical symptoms, specific serological markers, HLA-DQ2/DQ8 haplotype and enteropathy. The criteria followed for this have usually been those established by the European Society for Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) since 1969. These criteria have advanced from the need of several intestinal biopsies to, thanks to the development of serological tests of high sensitivity and specificity, considering the enteropathy as one more element in this diagnosis and makes it possible to perform a diagnosis without the need of an intestinal biopsy in certain circumstances. The updated review of the 2012 criteria in 2019 provides new evidence on some aspects, such as the role of HLA, the diagnosis of asymptomatic patients, and the effectiveness of the serological markers. These aspects are reviewed in detail, with the aim of facilitating the rational application of the new 2020 criteria at all care levels. In this sense, Paediatric Primary Care is fundamental in the search for active cases and to perform a first serological study, being recommended that the diagnosis is always established by a Paediatric Gastroenterologist.

Recurrent Metabolic Alkalosis in a Cystic Fibrosis Patient: Coexistence with Congenital Chloride Diarrhea.

Metabolic alkalosis is uncommon in infancy. Cystic fibrosis (CF) patients can develop dehydration because of sweat salt or gastrointestinal losses; with the correct salt supplementation, the electrolyte alterations can be reversed. Here, we present a CF patient with recurrent metabolic alkalosis, initially oriented as pseudo-Bartter's syndrome. However, despite accurate treatment, patient needed daily intravenous fluids to maintain homeostasis. An extended study was made, including a urine study that could rule out Bartter's diagnosis. Finally, after a complementary test that included electrolyte stools study and genetic analysis, congenital chloride diarrhea could be diagnosed.

European Society Paediatric Gastroenterology, Hepatology and Nutrition Guidelines for Diagnosing Coeliac Disease 2020.

OBJECTIVES: The ESPGHAN 2012 coeliac disease (CD) diagnostic guidelines aimed to guide physicians in accurately diagnosing CD and permit omission of duodenal biopsies in selected cases. Here, an updated and expanded evidence-based guideline is presented. METHODS: Literature databases and other sources of information were searched for studies that could inform on 10 formulated questions on symptoms, serology, HLA genetics, and histopathology. Eligible articles were assessed using QUADAS2. GRADE provided a basis for statements and recommendations. RESULTS: Various symptoms are suggested for case finding, with limited contribution to diagnostic accuracy. If CD is suspected, measurement of total serum IgA and IgA-antibodies against transglutaminase 2 (TGA-IgA) is superior to other combinations. We recommend against deamidated gliadin peptide antibodies (DGP-IgG/IgA) for initial testing. Only if total IgA is low/undetectable, an IgG-based test is indicated. Patients with positive results should be referred to a paediatric gastroenterologist/specialist. If TGA-IgA is ≥10 times the upper limit of normal (10× ULN) and the family agrees, the no-biopsy diagnosis may be applied, provided endomysial antibodies (EMA-IgA) will test positive in a second blood sample. HLA DQ2-/DQ8 determination and symptoms are not obligatory criteria. In children with positive TGA-IgA <10× ULN at least 4 biopsies from the distal duodenum and at least 1 from the bulb should be taken. Discordant results between TGA-IgA and histopathology may require re-evaluation of biopsies. Patients with no/mild histological changes (Marsh 0/I) but confirmed autoimmunity (TGA-IgA/EMA-IgA+) should be followed closely. CONCLUSIONS: CD diagnosis can be accurately established with or without duodenal biopsies if given recommendations are followed.