Abstract: Ｏｂｊｅｃｔｉｖｅ：To investigate the constitute and metabolic changes of intestinal microflora in patients with posttransplantation diabetes mellitus (PTDM) after kidney transplantation, and to evaluate the predictive value of differential microflora in diabetes mellitus after kidney transplantation.
Ｍｅｔｈｏｄｏｌｏｇｙ：Kidney transplant recipients who underwent surgery and follow-up in Lihuili Hospital affiliated to Ningbo University from January 2001 to July 2022 were divided into PTHG group [post-transplantation hyperglycemia, including PTDM group and posttransplantation prediabetes mellitus (prePTDM) group] and normal blood glucose group. Their fecal samples were sequenced by 16s rRNA gene V3-V4 region. The sonstitute and function of fecal microflora in PTHG group and normal blood glucose group were compared, the relationship between differential microflora and clinical physicochemical indexes was analyzed.
Ｒｅｓｕｌｔｓ：92 renal transplant recipients were stuclied, including 36 cases in PTHG group (29 cases in PTDM group and 7 cases in prePTDM group). Compared with the group with normal blood glucose, the abundance and diversity of fecal microflora in patients with PTHG were not significantly changed (P>0.05). In PTHG group, the relative abundance of Gemmiger and Anaerobacterium increased significantly, while that of Flavobacterium, Bifidobacterium and Parasutterella decreased significantly (P<0.05). Correlation analysis showed that Gemmiger and Anaerobacterium had a significant positive correlation with fasting blood glucose, while Erysipelotrichaceae_incertae_sedis had a significant negative correlation with fasting blood glucose (correlation>0.3 and P<0.05). The ROC curve (AUC=0.830) was drawn with the above six bacteria, and the flora combined with fasting blood glucose was analyzed (AUC=0.962), which was higher than the diagnostic efficiency of fasting blood glucose alone. Carbohydrate metabolic pathways such as amino sugar, nucleoside sugar and galactose metabolism and bile acid biosynthesis were significantly decreased in PTHG group. Subgroup analysis showed that Desulfovibrio, Anaerobacterium and Gemmiger showed a decreasing trend among PTDM, prePTDM and Normal groups, but the trend was not significant.
Ｃｏｎｃｌｕｓｉｏｎ：The constitute and function of intestinal flora in patients with PTDM changed significantly, and the difference of microflora was significantly related to glucose metabolism. Some of the microflora showed a decreasing trend among PTDM, prePTDM and normal blood glucose groups.

Key words: intestinal microflora, post-transplantation diabetes mellitus, 16S rRNA gene sequencing, kidney transplantation