The severity of cardiac damage was highest in the dysbiotic HF‐HCD‐fed hyperglycaemic rats, which was evident with increased serum creatine kinase‐MB (CK‐MB), cardiac troponin I (cTnI), tumour necrosis factor‐α, and interleukin‐6 levels, along with a decrease in ST‐segment resolution index. Here, TNNI3 is linked to hydrops fetalis.