1. Division of Cardiology, Department of Internal Medicine, Armed Force Taichung General Hospital, Taichung, Taiwan;
2. Department of Food Science and Technology, HungKuang University, Taiwan;
3. Department of Biological Science and Technology, China Medical University, Taichung, Taiwan;
4. Graduate Institute of Chinese Medical Science, China Medical University, Taichung, Taiwan;
5. Chinese Medicine Department, China Medical University Beijing Hospital, Taiwan;
6. Department of Nursing, Meiho University, Pingtung, Taiwan;
7. Division of Cardiology, China Medical University Hospital, Taichung, Taiwan;
8. Department of Hospital and Health Care Administration, Chia Nan University of Pharmacy & Science, Tainan County, Taiwan;
9. New Bellus Enterprises Co., Ltd. No. 48, Industrial Rd., Erh Chen Vil., Kuan Tien Dist., Tainan City, Taiwan;
10. Institute of Biomedical Nutrition, Hungkuang University, Taichung, Taiwan;
11. Graduate Institute of Basic Medical Science, China Medical University, Taichung, Taiwan;
12. Department of Health and Nutrition Biotechnology, Asia University, Taichung, Taiwan.
* These authors contributed equally to this work.
High-fat diets induce obesity, leading to cardiomyocyte fibrosis and autophagy imbalance. In addition, no previous studies have indicated that probiotics have potential health effects associated with cardiac fibrosis and autophagy in obese rats.
This study investigates the effects of probiotics on high-fat (HF) diet-induced obesity and cardiac fibrosis and autophagy in rat hearts. Eight-week-old male Wistar rats were separated randomly into five equally sized experimental groups: Normal diet (control) and high-fat (HF) diet groups and groups fed a high-fat diet supplemented with low (HL), medium (HM) or high (HH) doses of multi-strain probiotic powders. These experiments were designed for an 8-week trial period. The myocardial architecture of the left ventricle was evaluated using Masson's trichrome staining and immunohistochemistry staining. Key probiotics-related pathway molecules were analyzed using western blotting. Abnormal myocardial architecture and enlarged interstitial spaces were observed in HF hearts. These interstitial spaces were significantly decreased in groups provided with multi-strain probiotics compared with HF hearts. Western blot analysis demonstrated that key components of the TGF/MMP2/MMP9 fibrosis pathways and ERK5/uPA/ANP cardiac hypertrophy pathways were significantly suppressed in probiotic groups compared to the HF group. Autophagy balance is very important in cardiomyocytes. In this study, we observed that the beclin-1/LC3B/Atg7 autophagy pathway in HF was increased after probiotic supplementation was significantly decreased. Together, these results suggest that oral administration of probiotics may attenuate cardiomyocyte fibrosis and cardiac hypertrophy and the autophagy-signaling pathway in obese rats.
Keywords: High-fat diet, Obesity, probiotics, Autophagy.