AB-Kefir probiotics ameliorate dyslipidaemia and endothelial dysfunction in high-fat diet-induced obese rats

Cardiovascular diseases are a leading cause of mortality worldwide, with dyslipidaemia and endothelial dysfunction as critical underlying risk factors. This study evaluated the therapeutic potential of commercial AB-Kefir in ameliorating dyslipidaemia and endothelial dysfunction in high-fat diet (HFD)-induced obese rats. Twenty-four male Sprague–Dawley rats were fed a normal diet, an HFD, or an HFD supplemented with AB-Kefir. Following the intervention, the rats were sacrificed, and the fasting lipid profiles were determined. Vascular endothelial dysfunction was assessed by examining acetylcholine-induced vasorelaxation in the thoracic aorta, while aortic inflammatory markers and oxidative stress levels were measured via enzyme-linked immunosorbent assay. AB-Kefir probiotics significantly improved dyslipidaemia, endothelial dysfunction, inflammation, and oxidative imbalance. Specifically, AB-Kefir probiotic reduced total cholesterol, low-density lipoprotein, triglycerides, and the atherogenic index, while increasing high-density lipoprotein levels. Furthermore, AB-Kefir improved obesity-associated endothelial dysfunction by restoring acetylcholine-induced aortic relaxation. Pharmacological inhibition with L-nitro-arginine methyl ester and wortmannin confirmed the involvement of nitric oxide-dependent endothelial signalling via the PI3K/Akt pathway in mediating these vascular benefits. Meanwhile, AB-Kefir reduced vascular tumour necrosis factor-α and increased superoxide dismutase activity without significantly altering interleukin-6 or malondialdehyde levels. Ultimately, within a single obesity model, this study demonstrates the integrated therapeutic effects of a standardized AB-Kefir probiotic on lipid metabolism, endothelial signalling, inflammation, and antioxidant defence. These findings provide functional vascular evidence beyond the generic anti-inflammatory and antioxidant effects of fermented foods, supporting the potential of AB-Kefir as a complementary nutritional strategy for mitigating obesity-associated cardiometabolic risks.