TJP1 and hydrops fetalis: Following Shenfu Injection treatment, as compared to untreated HF rats, the SFI group exhibited mitigated histological lesions in myocardial and colonic tissues, a significant increase in ZO-1 and occludin protein expression, a notable rise in the gut microbiota health index, a decrease in the dysbiosis index, an increase in OTUs, a significant increase in species richness, an enhancement of species diversity, and an improved microbiota structure.