Relationship between intestinal microecological imbalance and gastrointestinal functional injury following cardiopulmonary bypass surgery

AIM To investigate the changes in intestinal microecology in patients following cardiopulmonary bypass surgery (CPB) and to examine the association between these changes and gastrointestinal functional injury (GFI).

METHODS  This study included 151 patients who underwent CPB at our hospital from March 2023 to June 2024. Within seven days post-surgery, patients were categorized into an injury group and a non-injury group based on the presence of GFI. The relative abundance and diversity of intestinal flora were compared between the two groups before and after surgery. Additionally, comparisons were made among patients with different grades of GFI. Spearman’s correlation analysis was used to assess the relationship between the relative abundance and diversity of intestinal flora and GFI following CPB.

RESULTS Seven days after surgery, 19.87% of the 151 patients who underwent extracorporeal circulation surgery experienced gastrointestinal dysfunction, including 13 cases of grade I, 11 cases of grade II, and 6 cases of grade III, respectively; Compared with the non-invasive group, patients in the injury group had longer cardiopulmonary bypass (CPB) time (P<0.05) and longer postoperative hospitalization time (P<0.01); There was no statistically significant difference in the preoperative comparison of Enterobacteriaceae, Enterococcus, Staphylococcus, Clostridium, Lactobacillus, Bifidobacterium, Shannon index, Simpson index between the two groups; Compared with the postoperative non-invasive group and the preoperative group, the relative abundance of Enterobacteriaceae (P<0.05), Enterococcus (P<0.05), Clostridium (P<0.01), and Staphylococcus (P<0.05) increased, while the relative abundance of Lactobacillus (P<0.01), Bifidobacterium (P<0.05), Shannon index (P<0.05), and Simpson index (P<0.01) decreased. Spearman correlation analysis showed that the relative abundance of Enterobacteriaceae, Enterococcus, Clostridium, and Staphylococcus was positively correlated with the grading of gastrointestinal functional injury (all P<0.01), while the relative abundance of Lactobacillus, Bifidobacterium, Shannon index, Simpson index were negatively correlated with the grading of gastrointestinal functional injury (all P<0.01).

CONCLUSION  Intestinal microecological imbalance in patients following CPB is closely associated with the incidence and severity of GFI.