RÉSUMÉ
Objective:To explore the characteristics of gut microbiota in the preoperative, short-term postoperative and long-term postoperative period at (15.61±4.51) months in children with ventricular septal defect (VSD) of congenital heart disease (CHD) treated with cardiopulmonary bypass (CPB).Methods:A prospective study was conducted.In Guangzhou Women and Children′s Medical Center, 13 patients with VSD who were scheduled for CPB and additional 10 age- and gender-matched healthy infants as pre-CPB control group from January 2021 to January 2022 were enrolled.Fecal samples were collected at pre- and early post-CPB.Meanwhile, 18 gender- and CHD diagnosis and operation-matched patients at (15.61±4.51) months after CPB and 8 healthy age- and gender-matched children as long-term control group after CPB were also enrolled, and fecal samples were collected.16S rRNA sequencing of fecal samples from all subjects were performed and comparing the differences in gut microbiota between two groups via comparing alpha and beta diversity, parameter test or nonparametric test, and LEfSe analysis.Results:Compared with those of pre-CPB control group, there was a significant difference in the composition of gut microbiota in the preoperative period of VSD children, with significantly increased abundances of Enterobacteriaceae and Shigella, and decreased abundance of Bifidobacterium (all P<0.05). The diversity of gut microbiota was comparable in VSD children before CPB and in the short period time after CPB (all P>0.05), except for the abundances of Clostridium and Streptococcus (all P<0.05), and there was no significant difference in the relative abundances of other highly abundant gut bacteria between the two periods (all P>0.05). Compared with that in VSD children in the short period time after CPB, the abundances of short-chain fatty acids-producing microbes were significantly higher at (15.61±4.51) months postoperatively (all P<0.05), and the gut bacteria profile was similar to that of the long-term control group after CPB (all P>0.05). Conclusions:Gut microbiota imbalance exists in VSD children before CPB.The gut microbiota profile is not influenced by CPB, which returns normal at (15.61±4.51) months postoperatively.