Abstract
INTRODUCTION: Obesity remains a critical global health challenge, intricately linked to poor dietary quality, gut microbiota dysbiosis, and mitochondrial dysfunction. PURPOSE: This study aimed to investigate the comparative effects of brown rice, meal replacements, and thiazolidinediones on mitochondrial abundance and gut microbiota composition in a rat model of diet-induced obesity. METHODS AND MATERIALS: A total of twenty male Sprague Dawley rats were randomly assigned to five groups: control, high-fat high-fructose diet, and three intervention groups receiving the same obesogenic diet supplemented with brown rice, meal replacement, or thiazolidinediones for twelve weeks. Mitochondrial activity in white adipose tissue was quantified using fluorescent staining techniques, while gut microbiota composition was assessed by analyzing the Firmicutes-to-Bacteroidetes ratio through quantitative PCR. RESULTS: Significant differences were observed in fiber intake and gut microbiota composition across groups (p < 0.001). The brown rice (BR) group exhibited the highest fiber intake (6.36 ± 1.01 g/day) and a favorable Firmicutes/Bacteroidetes ratio (1.36 ± 0.09). Mitochondrial count was significantly higher in the meal replacement (MR) group (60 ± 4.08) compared to the HFHF group (30 ± 2.89; p < 0.001). These findings suggest that high-fiber dietary interventions may enhance mitochondrial biogenesis and improve gut microbial balance, providing metabolic benefits in diet-induced obese models. CONCLUSION: These findings demonstrate that dietary fiber-rich interventions can modulate host metabolism through concurrent improvement of gut microbiota and mitochondrial function. Brown rice and meal replacements offer promising, non-pharmacological strategies for obesity management, while pharmacological agents such as thiazolidinediones may provide additive benefits through targeted mitochondrial enhancement. This study supports an integrated approach to metabolic health and underscores the significance of diet quality in the prevention and treatment of obesity.