IDDF2022-ABS-0209 The potential of amino acids and GUT microbiota to predict and promote mucosal healing of ulcerative colitis

BackgroundMucosal healing (MH) is a treatment goal in ulcerative colitis (UC). Amino acids (AA) and gut microbiota are involved in the development of UC, but the specific role and mechanism in MH remain unknown.Methods15 UC patients with infliximab-induced MH were enrolled. Gas-Chromatography/Mass-Spectrometer detected serum and fecal AA concentrations. The receiver operator characteristic curve (ROC) was plotted to evaluate the value of different AA in predicting MH. Fecal gut microbiota was analyzed by metagenomics.Results1. The fecal concentrations of 18 AA except L-4-hydroxyproline were decreased after MH. The serum concentrations of Alanine, Cysteine and Valine were significantly increased, while Aspartic acid was decreased.2. Fecal Glutamic acid, Leucine, Lysine, Methionine and Threonine had high accuracy in predicting MH, the AUC were > 0.9.3. Firmicutes, Bacteroidetes, Proteobacteria and Ascomycota were dominant in UC, the proportion of Firmicutes and Bacteroidetes increased significantly after MH. At the level of genus, Bacteroides, Enterococcus, Saccharomyces and Lactobacillus were dominant in UC, while Bacteroides, Faecalibacterium, Roseburia and Clostridium were dominant after MH. At the level of species, Enterococcus faecium and Escherichia coli were dominant in UC, while Faecalibacterium prausnitzii was dominant after MH.4. There were significant differences in the structure of microbiota between UC and MH at different levels. 2495 species increased after MH, such as Bacteroides Fragilis and Bacteroides vulgatus, while 329 species decreased, such as Enterococcus faecalis.5. A total of 89 differences were detected in LEfSe analysis. The following species were significantly elevated after MH: Faecalibacterium prausnitz, Bacteroides fragili, Eubacterium hallii.6. 82 metabolic pathways were enriched after MH, mainly in carbohydrate metabolism, amino acid metabolism and biosynthesis of fatty acids.Conclusions1. Fecal Glutamic acid, Leucine, Lysine, Methionine and Threonine had high sensitivity and specificity in predicting MH, and had the potential to become novel adjuvant biomarkers for MH.2. After MH, the diversity of gut microbiota increased and the structure changed. Species of producing SCFA increase obviously, represented by Faecalibacterium prausnitzii, Bacteroides fragilis and Eubacterium hallii.3. Multiple AA metabolic pathways were enriched after MH, may affect the gut microbiota, and participated in intestinal epithelial metabolism to p