P572 Half of children with acute severe colitis have predominant single faecal bacterial species, mostly Escherichia coli: Microbiome results from the PRASCO trial
Notice bibliographique
Résumé
Acute severe ulcerative colitis (ASC) is one of the few medical emergencies of gastroenterology. We previously reported the clinical results of the PRASCO randomised controlled trial in which oral antibiotics (AB) improved disease activity after 5 days of treatment in children with ASC. This suggests that the microbiome is implicated in the aetiology and progression of ASC. We thus aimed to explore the microbiome of children enrolled in the PRASCO trial. In the PRASCO trial, 26 children with ASC were randomised: 11 received IV corticosteroids (IVCS) and 15 received four oral AB's (amoxycillin, doxycillin/ciprofloxacin, metronidazole, vancomycin) in addition to IVCS. Stool samples were collected at regular intervals during admission. Metagenomic sequencing was performed using Illumina Nextera XT library preparation kit on a HiSeq platform. After filtering low quality and human reads using the KneadData pipeline, species-level taxonomic abundances were inferred for all samples using MetaPhlAn2. At baseline before treatment, 14/26 (54%) children harboured more than 30% of a single species: 9 (35%) with Escherichia coli, 2 (7.7%) Haemophilus species, and 1 (3.8%) each with Klebsiella pneumoniae, Barnesiella intestinihominis or Parabacteroides sp. (none with Fusobacterium varium). interestingly, of the 15 children in the AB arm, 11 (73%) had a transient relative bloom of >50% Enterobacteriaceae (mainly E. coli) after treatment, compared with only 3/11 in the IVCS only arm (p = 0.02). Despite this, disease activity at Day 5 was lower in the AB arm and time to remission was shorter (p = 0.049). When analysing all samples, several species of Lachnospiraceae family and Clostridium bartlettii were significantly and positively associated with remission. C. bartletti and R. torques (previously observed to be depleted in IBD and known butyrate producers) were lower in children with more severe disease. This is the first report of microbiome pattern in ASC, showing provocative results. Over half of children with ASC have gut microbiomes highly enriched (>30%) at baseline with a specific species, mostly Enterobacteriaceae. This association may suggest that some ASC episodes are triggered by yet unknown enteric infections. While our antibiotic cocktail transiently exacerbated this enrichment it reduced disease activity, possibly due to niche availability after treatment, which can subsequently be filled by butyrate-producing microbes. In addition, the enrichment is relative to other species; it is possible that the absolute count was much lower in the AB group. Dysregulation of butyrate production may be associated with ASC in children. This study was supported by grants from: IOIBD, Helmsley Charitable Trust and Janssen
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,002 | 0,004 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,001 | 0,001 |
| Bibliométrie | 0,000 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,001 |
| Communication savante | 0,001 | 0,001 |
| Science ouverte | 0,000 | 0,001 |
| Intégrité de la recherche | 0,001 | 0,002 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,010 | 0,002 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule source (Gemma direct ou Codex distillé), pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».