Systemic chronic hypoxia is a feature of many diseases and may influence the communication between bone marrow (BM) and gut microbiota. Here we analyse patients with cyanotic congenital heart disease (CCHD) who are experiencing chronic hypoxia and characterize the association between bone marrow mesenchymal stem cells (BMSCs) and gut microbiome under systemic hypoxia. We observe premature senescence of BMSCs and abnormal d-galactose accumulation in patients with CCHD. The hypoxia that these patients experience results in an altered diversity of gut microbial communities, with a remarkable decrease in the number of Lactobacilli and a noticeable reduction in the amount of enzyme-degraded d-galactose. Replenishing chronic hypoxic rats with Lactobacillus reduced the accumulation of d-galactose and restored the deficient BMSCs. Together, our findings show that chronic hypoxia predisposes BMSCs to premature senescence, which may be due to gut dysbiosis and thus induced d-galactose accumulation.

The modified Nikaidoh procedure is a better surgical option for transposition of the great arteries, ventricular septal defect, and pulmonary stenosis in terms of physiologic cardiac hemodynamics. Its long-term benefits need to be evaluated with a larger number of patients and longer follow-up.

In this study, we assessed the clinical effect of a new transfusion therapy guided by thromboelastograph (TEG) on blood protection. Thirty-one children with severe cyanosis (hematocrit ≥54%), who were diagnosed as having transposition of the great arteries or double outlet right ventricle with or without pulmonary valve stenosis, and underwent arterial switch operation or double roots transplantation, were involved and were divided into two groups. In group F (n=17), the transfusion therapy after cardiopulmonary bypass was performed with fibrinogen administration combined with traditional transfusion, guided by TEG. In group C (n=14), traditional transfusion guided by clinical experiences only was performed. We observed the blood protection effects and recovery conditions of these patients. In surgery, compared with group C, the chest closure time, fresh-frozen plasma (FFP), and platelet (PLT) volume used at closure time had no significant reductions in group F (P>0.05, respectively), and the patients in group F had no significant reductions in the amount of chest drainage (P>0.05). The total PLT and total red blood cells usage were also the same (P>0.05). But during the first 24h, FFP usage in the intensive care unit (ICU) and total perioperative FFP usage had significantly dropped in group F (P<0.05); the mechanical ventilator time, ICU stay, and hospitalization time in group F were much shorter than those in group C (P<0.05). So, TEG was effective in perioperative blood protection. Fibrinogen could be a substitute for FFP to restore hemostasis and improve the prognosis for these patients.