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"de Meij, Tim"
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Characterization of Microbiota in Children with Chronic Functional Constipation
by
Kneepkens, C. M. Frank
,
de Groot, Evelien F. J.
,
van Bodegraven, Adriaan A.
in
Adolescent
,
Bacteroides fragilis
,
Bacteroides ovatus
2016
Disruption of the intestinal microbiota is considered an etiological factor in pediatric functional constipation. Scientifically based selection of potential beneficial probiotic strains in functional constipation therapy is not feasible due to insufficient knowledge of microbiota composition in affected subjects. The aim of this study was to describe microbial composition and diversity in children with functional constipation, compared to healthy controls.
Fecal samples from 76 children diagnosed with functional constipation according to the Rome III criteria (median age 8.0 years; range 4.2-17.8) were analyzed by IS-pro, a PCR-based microbiota profiling method. Outcome was compared with intestinal microbiota profiles of 61 healthy children (median 8.6 years; range 4.1-17.9). Microbiota dissimilarity was depicted by principal coordinate analysis (PCoA), diversity was calculated by Shannon diversity index. To determine the most discriminative species, cross validated logistic ridge regression was performed.
Applying total microbiota profiles (all phyla together) or per phylum analysis, no disease-specific separation was observed by PCoA and by calculation of diversity indices. By ridge regression, however, functional constipation and controls could be discriminated with 82% accuracy. Most discriminative species were Bacteroides fragilis, Bacteroides ovatus, Bifidobacterium longum, Parabacteroides species (increased in functional constipation) and Alistipes finegoldii (decreased in functional constipation).
None of the commonly used unsupervised statistical methods allowed for microbiota-based discrimination of children with functional constipation and controls. By ridge regression, however, both groups could be discriminated with 82% accuracy. Optimization of microbiota-based interventions in constipated children warrants further characterization of microbial signatures linked to clinical subgroups of functional constipation.
Journal Article
The Potential of Fecal Volatile Organic Compound Analysis for the Early Diagnosis of Late-Onset Sepsis in Preterm Infants: A Narrative Review
2024
Early diagnosis and treatment of late-onset sepsis (LOS) is crucial for survival, but challenging. Intestinal microbiota and metabolome alterations precede the clinical onset of LOS, and the preterm gut is considered an important source of bacterial pathogens. Fecal volatile organic compounds (VOCs), formed by physiologic and pathophysiologic metabolic processes in the preterm gut, reflect a complex interplay between the human host, the environment, and microbiota. Disease-associated fecal VOCs can be detected with an array of devices with various potential for the development of a point-of-care test (POCT) for preclinical LOS detection. While characteristic VOCs for common LOS pathogens have been described, their VOC profiles often overlap with other pathogens due to similarities in metabolic pathways, hampering the construction of species-specific profiles. Clinical studies have, however, successfully discriminated LOS patients from healthy individuals using fecal VOC analysis with the highest predictive value for Gram-negative pathogens. This review discusses the current advancements in the development of a non-invasive fecal VOC-based POCT for early diagnosis of LOS, which may potentially provide opportunities for early intervention and targeted treatment and could improve clinical neonatal outcomes. Identification of confounding variables impacting VOC synthesis, selection of an optimal detection device, and development of standardized sampling protocols will allow for the development of a novel POCT in the near future.
Journal Article
Electronic Nose Sensor Drift Affects Diagnostic Reliability and Accuracy of Disease-Specific Algorithms
by
Seinen, Margien
,
Kuyvenhoven, Johan
,
Stokkers, Pieter C. F.
in
Accuracy
,
Algorithms
,
Breath Tests
2022
Sensor drift is a well-known disadvantage of electronic nose (eNose) technology and may affect the accuracy of diagnostic algorithms. Correction for this phenomenon is not routinely performed. The aim of this study was to investigate the influence of eNose sensor drift on the development of a disease-specific algorithm in a real-life cohort of inflammatory bowel disease patients (IBD). In this multi-center cohort, patients undergoing colonoscopy collected a fecal sample prior to bowel lavage. Mucosal disease activity was assessed based on endoscopy. Controls underwent colonoscopy for various reasons and had no endoscopic abnormalities. Fecal eNose profiles were measured using Cyranose 320®. Fecal samples of 63 IBD patients and 63 controls were measured on four subsequent days. Sensor data displayed associations with date of measurement, which was reproducible across all samples irrespective of disease state, disease activity state, disease localization and diet of participants. Based on logistic regression, corrections for sensor drift improved accuracy to differentiate between IBD patients and controls based on the significant differences of six sensors (p = 0.004; p < 0.001; p = 0.001; p = 0.028; p < 0.001 and p = 0.005) with an accuracy of 0.68. In this clinical study, short-term sensor drift affected fecal eNose profiles more profoundly than clinical features. These outcomes emphasize the importance of sensor drift correction to improve reliability and repeatability, both within and across eNose studies.
Journal Article
Infliximab in young paediatric IBD patients: it is all about the dosing
2020
Infliximab (IFX) is administered intravenously using weight-based dosing (5 mg/kg) in inflammatory bowel disease (IBD) patients. Our hypothesis is that especially young children need a more intensive treatment regimen than the current weight-based dose administration. We aimed to assess IFX pharmacokinetics (PK), based on existing therapeutic drug monitoring (TDM) data in IBD patients < 10 years. TDM data were collected retrospectively in 14 centres. Children treated with IFX were included if IFX was started as IBD treatment at age < 10 years (young patients, YP) and PK data were available. Older IBD patients aged 10–18 years were used as controls (older patients, OP). Two hundred and fifteen paediatric inflammatory bowel disease (PIBD) patients were eligible for the study (110 < 10 year; 105 ≥ 10 years). Median age was 8.3 years (IQR 6.9–8.9) in YP compared with 14.3 years (IQR 12.8–15.6) in OP at the start of IFX. At the start of maintenance treatment, 72% of YP had trough levels below therapeutic range (< 5.4 μg/mL). After 1 year of scheduled IFX maintenance treatment, YP required a significantly higher dose per 8 weeks compared with OP (YP; 9.0 mg/kg (IQR 5.0–12.9) vs. OP; 5.5 mg/kg (IQR 5.0–9.3); p < 0.001). The chance to develop antibodies to infliximab was relatively lower in OP than YP (0.329 (95% CI − 1.2 to − 1.01); p < 0.001), while the overall duration of response to IFX was not significantly different (after 2 years 53% (n = 29) in YP vs. 58% (n = 45) in OP; p = 0.56).Conclusion: Intensification of the induction scheme is suggested for PIBD patients aged < 10 years.What is Known?•Infliximab trough levels of paediatric IBD patients are influenced by several factors as dosing scheme, antibodies and inflammatory markers.•In 4.5–30% of the paediatric IBD patients, infliximab treatment was stopped within the first year.What is New?•The majority of young PIBD (< 10 years) have inadequate IFX trough levels at the start of maintenance treatment.•Young PIBD patients (< 10 years) were in need of a more intensive treatment regimen compared with older paediatric patients during 1 year of IFX treatment.•The chance to develop antibodies to infliximab was relatively higher in young PIBD patients (< 10 years).
Journal Article
Faecal Volatile Organic Compound Analysis in De Novo Paediatric Inflammatory Bowel Disease by Gas Chromatography–Ion Mobility Spectrometry: A Case–Control Study
by
de Jonge, Robert
,
Jagt, Jasmijn Z.
,
Covington, James A.
in
Adolescent
,
Care and treatment
,
Case-Control Studies
2024
The gut microbiota and its related metabolites differ between inflammatory bowel disease (IBD) patients and healthy controls. In this study, we compared faecal volatile organic compound (VOC) patterns of paediatric IBD patients and controls with gastrointestinal symptoms (CGIs). Additionally, we aimed to assess if baseline VOC profiles could predict treatment response in paediatric IBD patients. We collected faecal samples from a cohort of de novo therapy-naïve paediatric IBD patients and CGIs. VOCs were analysed using gas chromatography–ion mobility spectrometry (GC-IMS). Response was defined as a combination of clinical response based on disease activity scores, without requiring treatment escalation. We included 109 paediatric IBD patients and 75 CGIs, aged 4 to 17 years. Faecal VOC profiles of paediatric IBD patients were distinguishable from those of CGIs (AUC ± 95% CI, p-values: 0.71 (0.64–0.79), <0.001). This discrimination was observed in both Crohn’s disease (CD) (0.75 (0.67–0.84), <0.001) and ulcerative colitis (UC) (0.67 (0.56–0.78), 0.01) patients. VOC profiles between CD and UC patients were not distinguishable (0.57 (0.45–0.69), 0.87). Baseline VOC profiles of responders did not differ from non-responders (0.70 (0.58–0.83), 0.1). In conclusion, faecal VOC profiles of paediatric IBD patients differ significantly from those of CGIs.
Journal Article
The Influence of Mechanical Bowel Preparation on Volatile Organic Compounds for the Detection of Gastrointestinal Disease—A Systematic Review
by
De Vietro, Nicoletta
,
Arasaradnam, Ramesh P.
,
Hanna, George B.
in
Accuracy
,
Antigens
,
Biomarkers
2023
(1) Background: Colorectal cancer is the second commonest cause of cancer deaths worldwide; recently, volatile organic compounds (VOCs) have been proposed as potential biomarkers of this disease. In this paper, we aim to identify and review the available literature on the influence of mechanical bowel preparation on VOC production and measurement. (2) Methods: A systematic search for studies was carried out for articles relevant to mechanical bowel preparation and its effects on volatile organic compounds. A total of 4 of 1349 papers initially derived from the search were selected. (3) Results: Two studies with a total of 134 patients found no difference in measured breath VOC profiles after bowel preparation; one other study found an increase in breath acetone in 61 patients after bowel preparation, but no other compounds were affected. Finally, the last study showed the alteration of urinary VOC profiles. (4) Conclusions: There is limited data on the effect of bowel preparation on VOC production in the body. As further studies of VOCs are conducted in patients with symptoms of gastrointestinal disease, the quantification of the effect of bowel preparation on their abundance is required.
Journal Article
Maternal urinary metabolomic signatures preceding spontaneous preterm birth: A pilot study
2025
The etiological heterogeneity of spontaneous preterm birth (sPTB) complicates PTB risk prediction and management. Accurate risk stratification at clinical suspicion is critical to administer life-saving interventions for fetuses at genuine risk, while avoiding unnecessary treatments in pregnancies progressing to term to mitigate long-term complications. Current tools lack predictive accuracy, with 40% of suspected PTB delivering at term. This pilot study investigated signaling lipids as potential biomarkers for sPTB. Prospectively collected midstream urine of 30 women with imminent PTB were retrospectively classified into preterm without chorioamnionitis, preterm with chorioamnionitis, and term, and analyzed using liquid-chromatography mass-spectrometry. Overall-preterm vs. term analysis revealed reduced lipoxygenase- and cytochrome P450-derived oxylipins in the preterm group, suggesting impaired inflammation resolution. Pairwise comparisons showed that these differences were primarily driven by the non-infectious preterm group. Notably, 8,9-DiHETrE and 9-HODE emerged as promising etiology-independent biomarkers for sPTB. Furthermore, oxidative stress dominated non-infectious sPTB cases, while inflammatory cascades characterized the infectious cases. A predictive model incorporating 9-HODE and vaginal discharge demonstrated the ability (AUC 84.2%, sensitivity 73.7%, specificity 88.9%) to differentiate between women delivering preterm and at term. These findings highlight the potential of urinary metabolomics as a non-invasive tool to unravel sPTB pathophysiology and enhance risk prediction.
Journal Article
Erythrocyte Methotrexate–Polyglutamate Concentrations in Pediatric Inflammatory Bowel Disease
by
Struys, Eduard A
,
de Jonge, Robert
,
de Boer, Nanne K H
in
Adolescent
,
Child
,
Child, Preschool
2025
Abstract
Background and Aims
Therapeutic drug monitoring (TDM) of methotrexate (MTX) is challenging due to its pharmacokinetics and short plasma half-life. Intracellular MTX–polyglutamates (PG1–5), which accumulate over time, have not been assessed in pediatric inflammatory bowel disease (IBD). This study aimed to evaluate erythrocyte MTX-PG as a potential TDM tool in pediatric IBD.
Methods
In this cross-sectional study, MTX-PG concentrations were measured in erythrocytes of children with IBD on stable low-dose MTX for at least 12 weeks using stable-isotope dilution liquid chromatography–tandem mass spectrometry. The influence of administration route, MTX dosage, and anthropometrics on MTX-PG concentrations was examined.
Results
Seventy-eight patients were included, showing MTX-PG3 as the predominant subspecies (median 27.0 nmol/L) with a median MTX-PGtotal of 74.8 nmol/L. A higher MTX dose correlated significantly with elevated levels of MTX-PG3, MTX-PG4, MTX-PG5, and MTX-PGtotal (P < .01). Adjusted for body surface area, MTX dose remained significantly associated with higher MTX-PG concentrations (P < .01). However, comparison by administration route was limited due to a few patients on subcutaneous MTX (n = 4).
Conclusions
We observed high interindividual variability in the reached erythrocyte MTX-PG concentrations. Body surface adjusted or unadjusted MTX dosage showed a positive linear correlation with erythrocyte MTX-PG concentrations in children with IBD. This is a prerequisite for TDM and provides a strong basis for further research into the relation between TDM of MTX, efficacy, and toxicity.
Lay Summary
This study investigated erythrocyte methotrexate–polyglutamate (MTX-PG) levels in pediatric inflammatory bowel disease patients, finding that higher MTX doses correlate with increased long-chain MTX-PG concentrations. Results showed substantial interindividual variability, supporting further research on MTX-PG’s potential as a therapeutic drug monitoring tool.
Journal Article
Umbilical cord blood culture in neonatal early-onset sepsis: a systematic review and meta-analysis
by
de Meij, Tim G. J
,
van Kaam, Anton H. L. C
,
Visser, Douwe H
in
Diagnostic tests
,
Meta-analysis
,
Sepsis
2022
BackgroundPeripheral blood culture (PBC) is considered the gold standard for diagnosis of neonatal early-onset sepsis (EOS), but its diagnostic value can be questioned. We aimed to systematically asses the diagnostic test accuracy (DTA) of umbilical cord blood culture (UCBC) for EOS.MethodsA systematic literature search was performed in PubMed, Embase, Web of Science, and the Cochrane Library. Studies performing UCBC for the diagnosis of EOS were included.ResultsA total of 1908 articles were screened of which 17 were included. Incidences of positive PBC and UCBC were low in all studies. There was a large heterogeneity in the consistency between positive PBC and UCBC outcomes. PBC had a pooled sensitivity of 20.4% (95% CI 0.0–40.9) and specificity of 100.0% (95% CI 100.0–100.0) compared to 42.6% (95% CI 12.7–72.4%) and 97.8% (95% CI 93.1–100.0) of UCBC for clinical EOS, defined as clinical sepsis regardless of PBC outcomes.ConclusionsThis systematic review shows that, compared to PBC, UCBC has higher sensitivity and comparable specificity for clinical EOS and might be considered as diagnostic test for EOS. Due to the limited number of studies, low incidences of EOS cases, and the imperfect reference standards for EOS, results should be interpreted cautiously.ImpactThis is the first systematic review and meta-analysis investigating the diagnostic test accuracy of umbilical cord blood culture for neonatal early-onset sepsis.Peripheral blood culture is considered the gold standard for diagnosis of neonatal early-onset sepsis, but its value for this specific diagnosis can be questioned. Umbilical cord blood culture has higher sensitivity and comparable specificity for diagnosis of neonatal early-onset sepsis compared to peripheral blood culture, circumventing the risk for iatrogenic anemia and consequently might be used as a diagnostic tool for early-onset sepsis.Quality of evidence was regarded as low due to imperfect diagnostic methods of neonatal early-onset sepsis.
Journal Article
Exploring the Immunomodulatory Potential of Human Milk: Aryl Hydrocarbon Receptor Activation and Its Impact on Neonatal Gut Health
by
Lefèvre, Antoine
,
Davids, Mark
,
van Goudoever, Johannes B.
in
Acetic acid
,
aryl hydrocarbon receptors
,
Basic Helix-Loop-Helix Transcription Factors
2024
Several metabolites of the essential amino acid tryptophan have emerged as key players in gut homeostasis through different cellular pathways, particularly through metabolites which can activate the aryl hydrocarbon receptor (AHR). This study aimed to map the metabolism of tryptophan in early life and investigate the effects of specific metabolites on epithelial cells and barrier integrity. Twenty-one tryptophan metabolites were measured in the feces of full-term and preterm neonates as well as in human milk and formula. The ability of specific AHR metabolites to regulate cytokine-induced IL8 expression and maintain barrier integrity was assessed in Caco2 cells and human fetal organoids (HFOs). Overall, higher concentrations of tryptophan metabolites were measured in the feces of full-term neonates compared to those of preterm ones. Within AHR metabolites, indole-3-lactic acid (ILA) was significantly higher in the feces of full-term neonates. Human milk contained different levels of several tryptophan metabolites compared to formula. Particularly, within the AHR metabolites, indole-3-sulfate (I3S) and indole-3-acetic acid (IAA) were significantly higher compared to formula. Fecal-derived ILA and milk-derived IAA were capable of reducing TNFα-induced IL8 expression in Caco2 cells and HFOs in an AHR-dependent manner. Furthermore, fecal-derived ILA and milk-derived IAA significantly reduced TNFα-induced barrier disruption in HFOs.
Journal Article