A23 DIETARY PROTEIN AND AMINO ACID COMPOSITIONS INFLUENCE MICROBIOTA, INTESTINAL PERMEABILITY, AND SUSCEPTIBILITY TO COLITIS
Notice bibliographique
Résumé
Abstract Background Environmental factors, such as alterations in diet and microbiota, have been linked to inflammatory bowel diseases (IBD). The incidence of IBD is rising, particularly in Canada and other industrialized nations that consume western-style diets high in fat and protein. While most dietary proteins and amino acids are absorbed in the small intestine, substantial amounts can enter the colon for microbial metabolism and to exert effects on intestinal tissue and immune cells. Prospective cohort studies suggest that diets high in protein are associated with an increased risk of IBD. However, the role of excess dietary protein and amino acids in IBD pathogenesis is not clear. Aims To study whether and how consumption of diets high in protein or amino acids influences intestinal inflammation, colitis severity, and intestinal microbiota. Methods To assess the influence of dietary protein composition on colitis severity, specific pathogen-free C57BL/6 mice were fed isocaloric casein-based purified diets containing low (7%), normal (14%), or high (35%) protein (HPD). Mice were also fed an amino acid-defined diet (AAD) with amino acid and ingredient composition matched to the normal protein diet. Following three weeks of diet consumption ad libitum, mice were continued on the same diet and mucosal injury was induced with 2% dextran sulfate sodium (DSS; 5 days) followed by water (2 days) before sacrifice. Mice were monitored daily for clinical signs of colitis. Susceptibility to colitis was assessed by analysing stool consistency and blood, microscopic scoring (Cooper score), and by immunohistochemistry of colon tissue. Fecal microbiota (16S rRNA Illumina), intestinal permeability (Ussing chambers), proinflammatory gene expression (NanoString and RT-qPCR), and bacterial translocation (plating) were analysed. Results Following DSS exposure, mice fed HPD and AAD experienced greater weight loss, bacterial translocation to the spleen, stool blood, and diarrhea compared to mice fed the normal protein control diet. While all DSS-treated mice developed colitis, HPD and AAD fed mice also developed greater histologic damage, intestinal permeability, and innate immune cell infiltration. Cytokine profiling revealed that AAD is associated with significant up-regulation of IL-18 during colitis. Principle coordinates analysis based on Bray-Curtis dissimilarities demonstrates distinct shifts in the fecal microbiota of mice fed HPD and AAD. Conclusions These results suggest that excess dietary protein and amino acids are associated with more severe colitis and microbiota alterations in the DSS model. Previous studies demonstrate that IL-18 is up-regulated in IBD patients. Its overexpression may incite inflammation by stimulating cytokine signalling through NFκB and modify microbial community structure by regulating antimicrobial peptides. Funding Agencies CIHRFarncombe Family Digestive Health Research Institute, Douglas Family Chair in Gastroenterology Research
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 | 0,000 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,001 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,001 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,001 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,001 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,003 | 0,000 |
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 ».