The protective effect of probiotics on intestinal mucosal injury and dysbiosis in infants with congenital heart disease undergoing cardiopulmonary bypass

Purpose This study aimed to investigate alterations in intestinal mucosal barrier function and gut microbiota in pediatric patients with congenital heart disease undergoing cardiopulmonary bypass, and to evaluate whether perioperative probiotic administration improves intestinal homeostasis and clinical outcomes. Methods A randomized, double-blind, placebo-controlled trial was conducted in infants with non-cyanosis CHD in need of surgical correction with CPB. Infants aged 1 month to 1 year were enrolled between June 2021 and July 2022. Participants in the treatment group received perioperative probiotics containing Bifidobacterium infantis and Lactobacillus , while patients in control group were supplied with placebo. Clinical outcomes including diarrhea incidence, time to initiation of enteral nutrition and duration of gastrointestinal decompression were recorded. Blood samples were collected for measurement of intestinal fatty acid-binding protein (IFABP), diamine oxidase (DAO), D-lactate (D-LA), and C-reactive protein (CRP). Fecal samples were obtained to characterize alterations in gut microbiota. Results Intestinal mucosal barrier function was impaired after CPB surgery, as evidenced by significant increases in IFABP, DAO, D-LA and CRP levels. Additionally, CPB disrupted microbial diversity, increased the abundance of opportunistic pathogenic bacteria such as Enterococcus and decreased the abundance of beneficial microbiota such as Bifidobacterium . Post-surgery levels of IFABP and DAO were significantly lower in the treatment group than in the control group. However, no significant differences were observed for D-LA and CRP levels. Patients receiving probiotics initiated enteral feeding earlier. While the incidence of diarrhea and duration of gastrointestinal decompression did not differ between groups. Probiotic administration altered the baseline microbial community structure and partially attenuated CPB-induced alterations in bacterial diversity. Conclusions Infants with CHD undergoing CPB are at risk for intestinal mucosal barrier impairment and gut microbiota perturbation. Probiotics administration may alleviate intestinal injury and, to some extent, prevent dysbiosis after CPB. Further studies with larger sample sizes are warranted to validate the protective effect of probiotics in this setting.