[Cost-effectiveness analysis of a vaccine for Helicobacter pylori in southern Europe]. / Análisis coste-efectividad de una vacuna para Helicobacter pylori en el sur de Europa.

OBJECTIVE: There is sufficient evidence on the feasibility of a vaccine to prevent Helicobacter pylori infection. Modeling studies in low prevalence environments report a very probable long-term cost-effectiveness. The objective of this study was to quantify its efficiency in a local context. METHODS: The evolution of a cohort of newborns was simulated through a compartmental model representing a series of clinical situations regarding H. pylori infection and related diseases. The model was run under the assumption of both vaccination in the first year of life and no intervention. The time horizon was set as equivalent to the life expectancy and the perspective of the health system was taken into account. RESULTS: Vaccination against H. pylori would cost an average of €2,168/person more than no intervention. This would yield an average additional 0.32 quality-adjusted life years gained (QALY), which would entail an incremental cost-effectiveness ratio (ICER) of €7,196/QALY. For a willingness to pay of €24,506/QALY, 99.96% of the simulations were cost-effective at eighty-four years old. This threshold was crossed thirty years after vaccination. The variables that carried the most weight in explaining the variability of the ICER were, in this order, vaccine effectiveness, the incidence of infection in young children, and the price of the vaccine. Vaccination would cease to be cost-effective with a price greater than €3,634/dose or with effective population coverage less than 11%. CONCLUSIONS: When implemented in an environment with the epidemiological and economic characteristics of Southern Europe, a prophylactic vaccination against H. pylori would be cost-effective in the long run.

OBJECTIVE: Existen pruebas de la factibilidad de una vacuna para prevenir la infección por Helicobacter pylori. Modelizaciones en entornos de baja prevalencia informan de una muy probable coste-efectividad a largo plazo. El objetivo de este estudio fue cuantificar su eficiencia en un contexto local. METHODS: Se simuló la evolución de una cohorte de nacidos a través de un modelo compartimental representativo de varios estados clínicos en relación a la infección por H. pylori. Se ejecutó dicho modelo bajo las premisas de vacunación en el periodo de lactante y de no intervención. El horizonte temporal fue equivalente a la esperanza de vida y se tuvo en cuenta la perspectiva del sistema de salud. RESULTS: La vacunación frente a H. pylori costaría de media 2.168 €/persona más que la no intervención. Con ello se obtendrían 0,32 años de vida ganados ajustados por calidad (AVAC), lo que implicaría una razón de coste-efectividad incremental (RCEI) media de 7.196 €/AVAC. Para una disposición a pagar de 24.506 €/AVAC, el 99,96% de las simulaciones resultaron coste-efectivas al alcanzar el horizonte temporal y se cruzó dicho umbral a partir de los treinta años de la vacunación. Las variables que más peso tuvieron para explicar la variabilidad de la RCEI fueron, en este orden, la efectividad vacunal, la incidencia de la infección en la primera infancia y el precio de la vacuna. La vacunación dejaría de ser coste-efectiva con un precio mayor de 3.634€/vial o con una cobertura poblacional efectiva menor del 11%. CONCLUSIONS: Una vacunación frente a la infección por H. pylori administrada en la infancia sería coste-efectiva a largo plazo en un entorno con las características epidemiológicas y económicas del sur de Europa.

Benefits of Paediatric to Adult Transition Programme in Inflammatory Bowel Disease: The BUTTERFLY Study of GETECCU and SEGHNP.

(1) Background: Transition is a planned movement of paediatric patients to adult healthcare systems, and its implementation is not yet established in all inflammatory bowel disease (IBD) units. The aim of the study was to evaluate the impact of transition on IBD outcomes. (2) Methods: Multicentre, retrospective and observational study of IBD paediatric patients transferred to an adult IBD unit between 2017-2020. Two groups were compared: transition (≥1 joint visit involving the gastroenterologist, the paediatrician, a programme coordinator, the parents and the patient) and no-transition. Outcomes within one year after transfer were analysed. The main variable was poor clinical outcome (IBD flare, hospitalisation, surgery or any change in the treatment because of a flare). Predictive factors of poor clinical outcome were identified with multivariable analysis. (3) Results: A total of 278 patients from 34 Spanish hospitals were included. One hundred eighty-five patients (67%) from twenty-two hospitals (65%) performed a structured transition. Eighty-nine patients had poor clinical outcome at one year after transfer: 27% in the transition and 43% in the no-transition group (p = 0.005). One year after transfer, no-transition patients were more likely to have a flare (36% vs. 22%; p = 0.018) and reported more hospitalisations (10% vs. 3%; p = 0.025). The lack of transition, as well as parameters at transfer, including IBD activity, body mass index < 18.5 and corticosteroid treatment, were associated with poor clinical outcome. One patient in the transition group (0.4%) was lost to follow-up. (4) Conclusion: Transition care programmes improve patients' outcomes after the transfer from paediatric to adult IBD units. Active IBD at transfer impairs outcomes.

Safety and efficacy of a new supplementation protocol in patients with cystic fibrosis and vitamin D deficiency.

OBJECTIVES: Based on the European and American Cystic Fibrosis (CF) consensus recommendations, an increase in vitamin D (VD) supplementation in patients with CF and insufficient or defficient levels was proposed. The objective of our study was to determine the safety and efficacy of this new protocol. MATERIAL AND METHODS: Multicentre nonrandomized uncontrolled experimental study. Patients with insufficient levels (<30 ng/mL) received increasing doses of VD (between 800 and 10 000 IU/day). Patients were followed up for 12 months, during which their vitamin and nutritional status, pulmonary function and calcium and phosphate metabolism were assessed. STATISTICAL ANALYSIS: t test for paired data and multivariate logistic regression analysis. RESULTS: Thirty patients aged 1-39 years (median, 9.1) completed the follow-up. Two patients were dropped from the study on account of 25-OH VD levels greater than 100 ng/mL at 3 months without clinical or laboratory signs of hypercalcaemia. At 12 months, we observed an increase of 7.6 ng/mL (95% CI, 4.6-10 ng/mL) in the mean 25-OH VD level and an improvement in vitamin status: 37% achieved levels of 30 ng/mL or greater, 50% levels between 20 and 30 ng/mL and 13% remained with levels of less than 20 ng/mL. We found no association between improved VD levels and pulmonary function. CONCLUSIONS: The proposed protocol achieved an increase in serum VD levels and a decrease in the percentage of patients with VD insufficiency, although it was still far from reaching the percentages of sufficiency recommended for this entity.

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.

Cross-cultural adaptation to Spanish and content validity of three nutritional risk scales.

INTRODUCTION: There are various scales designed to determine the risk of malnutrition at hospital admission in children. However, most of these instruments are developed and published in English. Their cross-cultural adaptation and validation being mandatory in order to be used in our country. OBJECTIVES: Cross-culturally adapt three scales designed to determine the risk of malnutrition linked to the disease and determine the validity of their content. MATERIAL AND METHODS: Cross-cultural adaptation using the translation-back-translation method in accordance with the recommendations of the International Test Commission Guidelines for Translating and Adapting Tests. Content validity was measured by a panel of experts (under seven basic selection criteria adapted from the Fehring model) who evaluated each item of the scales by measuring 4 criteria: ambiguity, simplicity, clarity and relevance. With the extracted score, Aiken's V statistic was obtained for each item and for the complete scales. RESULTS: Starting from three independent translations per scale, 3 definitive versions in Spanish of the PNRS, STRONGkids and STAMP scales were obtained semantically equivalent to their original versions. The PNRS and STRONGkids scales presented an Aiken's V greater than 0.75 in all their items, while the STAMP scale presented a value less than 0.75 for the item "weight and height". CONCLUSION: This study provides the transculturally adapted Spanish versions of the PNRS, STRONGkids and STAMP scales. The PNRS and STRONGkids scales present valid content to be applied in the state hospital context. STAMP requires the adaptation of its item "weight and height" to consider its use in a Spanish child population adequate.

Vitamin D Status in Pediatric and Young Adult Cystic Fibrosis Patients. Are the New Recommendations Effective?

INTRODUCTION: In recent years, guidelines for vitamin D supplementation have been updated and prophylactic recommended doses have been increased in patients with cystic fibrosis (CF). OBJECTIVE: To evaluate safety and efficacy of these new recommendations. RESULTS: Two cohorts of pancreatic insufficient CF patients were compared before (cohort 1: 179 patients) and after (cohort 2: 71 patients) American CF Foundation and European CF Society recommendations were published. Cohort 2 patients received higher Vitamin D doses: 1509 (1306-1711 95% CI) vs 1084 (983-1184 95% CI) IU/Day (p < 0.001), had higher 25 OH vitamin D levels: 30.6 (27.9-33.26 95% CI) vs. 27.4 (25.9-28.8 95% CI) ng/mL (p = 0.028), and had a lower prevalence of insufficient vitamin D levels (<30 ng/mL): 48% vs 65% (p = 0.011). Adjusted by confounding factors, patients in cohort 1 had a higher risk of vitamin D insufficiency: OR 2.23 (1.09-4.57 95% CI) (p = 0.028). CONCLUSION: After the implementation of new guidelines, CF patients received higher doses of vitamin D and a risk of vitamin D insufficiency decreased. Despite this, almost a third of CF patients still do not reach sufficient serum calcidiol levels.

Usefulness of complementary test in the study of patients with chronic abdominal pain.

INTRODUCTION: Chronic abdominal pain (CAP) in children is a symptom that frequently leads to a visit to the paediatrician, which affects family life and occasionally requires the need to perform diagnostic studies (DS). The objective was to carry out a qualitative, quantitative, and economic analysis on the tests requested. MATERIAL AND METHODS: An observational, prospective and multicentre study was conducted that included children between 4-15 years old affected by CAP. The difference between organic and functional disorders was taken into account. The following variables were collected: history, warning signs and symptoms, DS, and the cost of these. RESULTS: The study included 235 children with CAP (Age; mean 9.7 ± 2.7 SD). The large majority (79%) were functional disorders and 21% organic disorders. Almost half of the patients had some warning sign or symptom, but urinary symptoms were only associated with organic disorders. The abdominal ultrasound, faecal parasites, breath test, and endoscopy were the most associated with organic disorders. There was a difference between the costs of the DS according to each centre. The total economic cost was 52,490.80 euros, with 195 euros per patient for functional disorders and 306 euros for organic disorders. CONCLUSION: Signs and symptoms of alarm in CAP were very frequent, but had low discriminative capacity. The abdominal ultrasound and faecal parasites are innocuous DS, and could be useful as a first level study. The endoscopy and the breath test were the most discriminative of organic disease. The economic cost of DS arising from the diagnosis of exclusion in CAP was high.

[Diagnosis of celiac disease in clinical practice: present and future]. / Diagnóstico de enfermedad celiaca en la práctica clínica: presente y futuro.

INTRODUCTION: European guidelines for the diagnosis of celiac disease (CD) have been updated in 2020. The primary objective was to review the compliance with the diagnostic criteria for CD, according to ESPGHAN 2012. Secondarily, to describe the clinical characteristics of the patients and to assess the changes that would be implied by the application of the new 2020 criteria. PATIENTS AND METHODS: Retrospective multicenter study in which 10 centers participated. Patients from 0 to 16 years old with a new diagnosis of CD in 2018-2019 were included. Clinical, serological variables and the performance of intestinal biopsy (IB) were collected. RESULTS: 163 patients were included (57% female) with a median age of 7.6 years (SD 4.4). The form of presentation was: 47.8% classical, 30.7% no classical and 21.5% asymptomatic, with differences depending on age. Total IgA and anti-transglutaminase IgA antibodies were performed in all centers as the first diagnostic step. IgA anti-endomysial antibodies (EMA) were performed in 80%, and HLA haplotype in 95%. Of the total, 78 cases (47.9%) met criteria for not performing intestinal biopsy (IB). IB was indicated in the remaining 85 patients, but was not performed in 29 cases (17.8%). The performance of IB was lower in the secondary hospitals than in the tertiary ones (p < 0.05). If we applied the ESPGHAN 2020 criteria, we would disregard the HLA study, and 21 more patients would not have required IB (going from 47.9% to 60.7% of the total). CONCLUSIONS: Discrepancies are observed in the application of the ESPGHAN 2012 diagnostic criteria due to the different accessibility to EMA and endoscopic IB in secondary centers. With the ESPGHAN-2020 criteria, around 60% of patients will be able to be diagnosed without IB, provided that the determination of EMA is ensured.

Hepatitis C and beta-thalassemia major in children: experience with glecaprevir/pibrentasvir.

Hepatitis C virus (HCV) is estimated to affect 3.26 million children worldwide, with the highest number of cases registered in Pakistan and China. Vertical transmission is the principal route in industrialized countries. However, iatrogenic transmission is relevant in low-income settings. We present the case of a 12-year-old Pakistani child who suffered from beta-thalassemia major and hepatitis C, successfully treated with glecaprevir/pibrentasvir.

COVID-19 Gastrointestinal Manifestations Are Independent Predictors of PICU Admission in Hospitalized Pediatric Patients.

Multicenter study conducted in 15 hospitals including 101 COVID-19 pediatric inpatients aiming to describe associated gastrointestinal (GI) manifestations. GI symptoms were present in 57% and were the first manifestation in 14%. Adjusted by confounding factors, those with GI symptoms had higher risk of pediatric intensive care unit admission. GI symptoms are predictive of severity in COVID-19 children admitted to hospitals.

Multicomponent Exercise Training Combined with Nutritional Counselling Improves Physical Function, Biochemical and Anthropometric Profiles in Obese Children: A Pilot Study.

Aerobics or strength exercise plus diet interventions have been shown to counteract childhood obesity. However, little is known with regard to periodized multicomponent exercise interventions combined with nutritional counselling, which might be less demanding but more enjoyable and respectful of children and adolescents' nature. In order to analyze the impact of such a multimodal approach, 18 obese children (10.8 ± 1.6 years; 63% females; z Body Mass Index 3 ± 0.4) trained for 60 min, twice weekly and were measured for body composition, biochemical parameters and physical function. We found that 16 weeks of multimodal intervention (14 of training), based on fun-type skill-learning physical activities and physical conditioning with challenging circuits and games, together with nutritional counselling, led to an attendance > 80%, with significant overall health improvement. Body composition was enhanced (p < 0.01 for z BMI, mid-upper-arm-circumference, waist-to-height ratio, tricipital and subscapular skinfolds, body-fat % by Slaughter equation and Dual energy X-ray absorptiometry body fat% and trunk fat%), as well as metabolic profile (LDL cholesterol, gamma-glutamyl transferase , alanine aminotransferase ; p < 0.05), homeostatic model assessment of insulin resistance (HOMA-IR; p < 0.05) and inflammatory response (C-Reactive Protein; p < 0.05). Physical fitness was also improved (p < 0.01) through better cardiovascular test scores and fundamental movement patterns (Functional Movement Screen-7, FMS-4). Tailoring multimodal supervised strategies ensured attendance, active participation and enjoyment, compensating for the lack of strict caloric restrictions and the low volume and training frequency compared to the exercise prescription guidelines for obesity. Nutritional counselling reinforced exercise benefits and turned the intervention into a powerful educational strategy. Teamwork and professionals' specificity may also be key factors.

Predictors of Response to Exclusive Enteral Nutrition in Newly Diagnosed Crohn´s Disease in Children: PRESENCE Study from SEGHNP.

Exclusive enteral nutrition (EEN) has been shown to be more effective than corticosteroids in achieving mucosal healing in children with Crohn´s disease (CD) without the adverse effects of these drugs. The aims of this study were to determine the efficacy of EEN in terms of inducing clinical remission in children newly diagnosed with CD, to describe the predictive factors of response to EEN and the need for treatment with biological agents during the first 12 months of the disease. We conducted an observational retrospective multicentre study that included paediatric patients newly diagnosed with CD between 2014-2016 who underwent EEN. Two hundred and twenty-two patients (140 males) from 35 paediatric centres were included, with a mean age at diagnosis of 11.6 ± 2.5 years. The median EEN duration was 8 weeks (IQR 6.6-8.5), and 184 of the patients (83%) achieved clinical remission (weighted paediatric Crohn's Disease activity index [wPCDAI] < 12.5). Faecal calprotectin (FC) levels (µg/g) decreased significantly after EEN (830 [IQR 500-1800] to 256 [IQR 120-585] p < 0.0001). Patients with wPCDAI ≤ 57.5, FC < 500 µg/g, CRP >15 mg/L and ileal involvement tended to respond better to EEN. EEN administered for 6-8 weeks is effective for inducing clinical remission. Due to the high response rate in our series, EEN should be used as the first-line therapy in luminal paediatric Crohn's disease regardless of the location of disease and disease activity.

Case Report: Primary Peritonitis as the Onset of Pediatric Ménétrier's Disease.

Introduction: Primary peritonitis (PP) and Ménétrier's Disease (MD) are both rare conditions among pediatric population. Although about 150 MD cases have been described in the scientific literature to date, its onset with a PP is an unusual condition. Case Presentation: We present a case of an 11-year-old boy who was admitted to our unit because of abdominal pain and distension. Complementary tests showed ascites, bilateral pleural effusion, leukocytosis, increased acute phase reactants and hypoproteinemia with hypoalbuminemia. Laparoscopy ruled out appendicitis or visceral perforations and exposed purulent peritoneal fluid, compatible with PP. Biochemical stool analysis showed increased clearance of alpha-1-antitrypsin, which was consistent with a protein-losing enteropathy. Gastroscopy findings were compatible with MD. The clinical course was favorable and he had no recurrence after 12 months of follow-up. Conclusion: PP can be the first clinical manifestation of pediatric MD. Knowledge of MD and its generally benign nature in children is important in order to avoid excessive testing and unnecessary treatment.

Assessment of nutritional status and bone health in neurologically impaired children: a challenge in pediatric clinical practice.

INTRODUCTION: Introduction: neurologically impaired children frequently experience nutritional disorders and bone health complications. Our aim was firstly to analyze a method to interpret bone mineral density (BMD) accurately in neurologically impaired children. Secondly, to determine its relationship with the nutritional status and micronutrient levels in order to identify which factors are associated with low BMD. Methods: a observational multicenter study was conducted in children with moderate-to-severe neurological impairment. Data collected included: medical records, anthropometric measures, hematologic and biochemical evaluation. BMD was measured with Dual-energy X-ray absorptiometry and z-scores were calculated adjusting for sex and chronological age. Secondly, BMD z-scores were calculated applying height age (age at which the child's height would be in 2nd percentile) instead of chronological age. Results: fifty-two children were included (aged 4-16 years). Seventeen patients (32.7%) received feeding by gastrostomy tube. Height and BMI z-score were below 2SD in 64% and 31% of patients respectively, with normal mid upper arm circumference and skinfold thickness measurements. Low vitamin-D levels were found in 42% of cases. 50% of patients evidenced low BMD when calculated for chronological age, whereas only 34.5% showed BMD z-score <-2 when calculated for height age. No correlation was observed between BMD and vitamin-D levels, weight and height z-scores or age when BMD was calculated applying height age. Conclusions: the prevalence of low BMD is high in neurologically impaired children, and it is probably multifactorial. In these children, we suggest adjusting BMD for height age, in order not to over diagnose low BMD.

INTRODUCCIÓN: Introducción: los niños con afectación neurológica con frecuencia presentan trastornos nutricionales y complicaciones óseas. Nuestro objetivo fue, en primer lugar, analizar un método para interpretar la densidad mineral ósea (DMO) de forma adecuada en estos pacientes. En segundo lugar, determinar la relación de la DMO con el estado nutricional y los niveles de micronutrientes, para determinar qué factores se asocian con baja DMO. Métodos: estudio observacional multicéntrico, se incluyeron niños con afectación neurológica moderada-severa. Se recogieron datos clínicos, medidas antropométricas y una evaluación hematológica y bioquímica. La DMO fue evaluada mediante densitometría, y se calcularon los z-scores según la edad y sexo. En segundo lugar, se recalcularon los z-scores de DMO para la edad talla (edad en la cual la talla del niño se encontraría en el percentil 2) en vez de la edad cronológica. Resultados: se incluyeron 52 niños (4-16 años). Diecisiete pacientes (32,7%) recibían alimentación por gastrostomía. Los z-scores de peso y talla estaban por debajo de 2 desviaciones estándar (DE) en el 64% y 31% de los pacientes respectivamente, con normalidad de las mediciones de perímetro braquial y pliegues tricipital y subescapular. Los niveles de vitamina D estaban bajos en el 42% de los casos. La mitad de los pacientes tenían baja DMO cuando se calculó para la edad cronológica, mientras que solo el 34,5% presentaron DMO por debajo de 2 DE cuando se calculó para la edad talla. No observamos correlación entre z-scores de DMO calculados para la edad talla y los niveles de vitamina D, la edad o los z-scores de peso y talla. Conclusiones: la prevalencia de baja DMO es alta en niños con discapacidad neurológica, y probablemente es multifactorial. En estos niños, sugerimos ajustar DMO para la edad talla, para evitar sobrediagnosticar baja DMO.

Nutritional Outcome in Home Gastrostomy-Fed Children with Chronic Diseases.

The aim of the study was to assess the anthropometric outcomes after gastrostomy tube (GT) placement in children with chronic diseases and the influence of primary diagnosis, age, and nutritional support. A longitudinal, multicenter, and prospective study was performed evaluating 65 children with GT feeding and chronic diseases (61.5% with neurological disease). Each child was evaluated three times (at baseline and at 6 and 12 months after GT placement) and the following data was collected: primary diagnosis, age at GT placement, anthropometry, and feeding regime. Repeated measures ANOVA were used to analyze the main effects (intra and intergroup) and the interactions effects on weight gain and linear growth at 6 and 12 months after GT placement. All patients significantly improved their body mass index (BMI)-for-age z-score (p < 0.001) and height-for-age z-score (p < 0.05) after 6 and 12-month of follow-up. BMI gain increased significantly the first 6 months, followed by a plateau, while height followed a linear trend. Children with GT placement before 18 months old experienced an accelerated growth rate during the first 6 months post-GT. This technique showed the effectiveness of GT placement improving nutritional status and growth catch up regardless of their primary diagnosis and the type of nutritional support.

Association of Maternal Secretor Status and Human Milk Oligosaccharides With Milk Microbiota: An Observational Pilot Study.

BACKGROUND AND OBJECTIVES: Breast milk contains several bioactive factors including human milk oligosaccharides (HMOs) and microbes that shape the infant gut microbiota. HMO profile is determined by secretor status; however, their influence on milk microbiota is still uncovered. This study is aimed to determine the impact of the FUT2 genotype on the milk microbiota during the first month of lactation and the association with HMO. METHODS: Milk microbiota from 25 healthy lactating women was determined by quantitative polymerase chain reaction and 16S gene pyrosequencing. Secretor genotype was obtained by polymerase chain reaction-random fragment length polymorphisms and by HMO identification and quantification. RESULTS: The most abundant bacteria were Staphylococcus and Streptococcus, followed by Enterobacteriaceae-related bacteria. The predominant HMO in secretor milk samples were 2'FL and lacto-N-fucopentaose I, whereas non-secretor milk was characterized by lacto-N-fucopentaose II and lacto-N-difucohexaose II. Differences in microbiota composition and quantity were found depending on secretor/non-secretor status. Lactobacillus spp, Enterococcus spp, and Streptococcus spp were lower in non-secretor than in secretor samples. Bifidobacterium genus and species were less prevalent in non-secretor samples. Despite no differences on diversity and richness, non-secretor samples had lower Actinobacteria and higher relative abundance of Enterobacteriaceae, Lactobacillaceae, and Staphylococcaceae. CONCLUSIONS: Maternal secretor status is associated with the human milk microbiota composition and is maintained during the first 4 weeks. Specific associations between milk microbiota, HMO, and secretor status were observed, although the potential biological impact on the neonate remains elusive. Future studies are needed to reveal the early nutrition influence on the reduction of risk of disease.