The plasma metabolome and clinical features of patients with coeliac disease in Northwest China

Objective Coeliac disease (CeD) is a relatively common autoimmune disease in Caucasian populations, but is rarely reported in China. The metabolic characteristics of Chinese patients with coeliac disease remain insufficiently characterised. Therefore, this study attempted to describe the metabolic profile of a small cohort Chinese patients with coeliac disease.Methods Plasma samples and dietary pattern information were collected from 15 patients with CeD, 15 healthy volunteers, and 30 patients with inflammatory bowel disease (IBD). Plasma metabolomic analysis was performed using a pseudo-targeted metabolomics approach based on ultra-high-performance liquid chromatography coupled with triple quadrupole-linear ion trap mass spectrometry (UHPLC-QTRAP-MS). Dietary intake was assessed via food frequency questionnaires, and metabolomics data were adjusted according to energy and 17 specific nutrient covariates.Results Despite reporting significantly higher daily intakes of protein and carbohydrate when compared to controls or IBD patients, CeD patients exhibited a relative insufficiency of micronutrient niacin. Several distinct metabolic alterations were identified in CeD patients relative to healthy controls, independent of dietary intake. These included decreased metabolites in the pentose phosphate pathway and increased intermediates of the citric acid cycle. The abundances of L-proline, D-proline, microbiota-related aromatic amino acid metabolites, glycine-conjugated bile acids, and the plant sterol panuosterone were increased. In contrast, the abundances of several long-chain acylcarnitines were reduced despite higher fat intake. These metabolic alterations existed in CeD but not in IBD patients.Conclusions CeD patients in Northwest China exhibit a unique metabolic profile distinct from IBD and healthy controls, involving host central carbon metabolism, glycerophospholipid metabolism, gut microbiota, and other factors. This might underscore the multifactorial nature of coeliac disease, implicating other factors beyond genetics and gluten.