Abstract: Objective To analyze the correlation between the abundance and diversity of intestinal flora in patients with primary biliary cholangitis (PBC) and the short-term response of ursodeoxycholic acid (UDCA). Methods 86 patients with PBC admitted to our hospital from May 2015 to May 2021 were selected as the research object (research group), and 86 patients with physical examination at the same time in our hospital were selected as the control (control group). We compared serum biochemical index levels of PBC patients before and one month after treatment. We also compared the differences in abundance and diversity between the research group before and one month after treatment with the control group. Then we evaluated the short-term response of UDCA in the two groups after one month of treatment and analyzed the correlation between the abundance and diversity of PBC patients and the short-term response of UDCA. The predictive value of the abundance and diversity of PBC patients before treatment on the short-term response of UDCA was assessed. Results The levels of TBA, ALT, AST, TBil, WBC and Scr in PBC patients after 1 month of treatment were (16.71 ± 8.29) μmol/L, (27.49 ± 10.25) U/L, (38.52 ± 19.27) U/L, (18.54 ± 7.31) μmol/L, (7.35 ± 1.42)×10⁹/L, (86.31 ± 12.43) μmol/L, which were all lower than those before treatment [(32.27 ± 11.45) μmol/L, (84.37 ± 21.93) U/L, (88.37 ± 31.62) U/L, (27.38 ± 8.12) μmol/L, (14.52 ± 2.17)×10⁹/L, (148.59 ± 23.16) μmol/L], the differences were statistically significant (P<0.05). Before treatment, the abundance (Chao1 index) and diversity level (Shannon index) of the research group were (441.59 ± 35.49) and (2.54 ± 0.68), respectively, which were lower than those of the control group (706.35 ± 42.17, 3.31 ± 0.46), and the difference was statistically significant (P<0.05). After 1 month of treatment, the Chao1 index and Shannon index of the research group were higher than those before treatment, and the difference was statistically significant (P<0.05). And after 1 month of treatment, the Chao1 index and Shannon index of the research group were (631.27 ± 51.36), (3.01±0.59) respectively, were all lower than those in the control group (703.49 ± 42.76), (3.37 ± 0.53), the difference was statistically significant (P<0.05). Spearman correlation analysis showed that the abundance level (r=0.772, P=0.024), diversity level (r=0.683, P=0.037) were positively correlated with short-term UDCA response. ROC analysis showed that the sensitivity of abundance and diversity to ROC prediction of short-term UDCA response in PBC patients were 74.14%, 72.41%, respectively, the specificity were 60.71%, 64.29%, and the area under the curve (AUC) were 0.764 and 0.737, respectively. Conclusion The abundance and diversity of the intestinal flora of PBC patients are positively correlated with the short-term UDCA response, and the abundance and diversity level have a certain clinical predictive power for the short-term UDCA response of PBC patients.

Key words: Primary biliary cholangitis, Abundance, Diversity, Ursodeoxycholic acid, Short-term response