Fig. 1: The level of HDCA is reduced in patients with NAFLD and diet-induced NAFLD mice.

a Schematic representation of the clinical sample analysis. Created with BioRender.com. b OPLSDA plot of serum BA profile in health (n = 24) and NAFLD (n = 34) individuals. c–h Serum level of HCA species, HDCA, GHDCA, HCA, GHCA, and THCA (n = 24 for Health, n = 34 for NAFLD). i Spearman correlation analysis between HCA species BAs and clinical characteristics (*p < 0.05, **p < 0.01). j Scatter plots of serum HDCA and HCA with serum ALT, AST, and CAP score. k–n The C57BL/6 mice were fed an HFHS diet for 24 weeks. k Levels of HCA species in the serum, liver, small intestinal (SI) content, cecum content, and colon content of diet-induced mice with NAFLD (n = 9 for Control, n = 8 for HFHS). l Level of individual HCA species in the serum of NAFLD mice (n = 9 for Control, n = 8 for HFHS). m Level of individual HCA species in the liver of NAFLD mice (n = 9 for Control, n = 8 for HFHS). n Spearman correlation analysis between HCA species, HDCA, and mouse phenotypes (*p < 0.05, ** p < 0.01, ***p < 0.001). Data are presented as mean values ± SEM. Differences between groups were determined by unpaired two-tailed Mann–Whitney U test. Source data are provided as a Source Data file.