Objective
To evaluate the synergic effects of a novel oral supplement formulation, containing prebiotics, yeast β-glucans, minerals and silymarin (Silybum marianum), on lipid metabolism and inflammatory and mitochondrial proteins of the liver, in control and high-fat diet-induced obese mice.

Methods
After an acclimation period, 32 male C57BL/6 mice were divided into the following groups: nonfat diet (NFD) vehicle, NFD supplemented, high-fat diet (HFD) vehicle and HFD supplemented. The vehicle and experimental formulation were administered orally by gavage once a day during the last four weeks of the diet (28 consecutive days). We then evaluated energy homeostasis, inflammation, and mitochondrial protein expression in these groups of mice.

Results
After four weeks of supplementation, study groups experienced reduced glycemia, dyslipidemia, fat, and hepatic fibrosis levels. Additionally, proliferator-activated receptor-α, AMP-activated protein kinase-1α, peroxisome proliferator-activated receptor γ co-activator 1-α, and mitochondrial transcription factor A expression levels were augmented; however, levels of IκB kinase α and p65 nuclear factor-κB expression, and oxidative markers were reduced. Notably, the cortisol/C-reactive protein ratio, a well-characterized marker of the hypothalamic-pituitary-adrenal axis immune interface status, was found to be modulated by the supplement.

Conclusion
We found that the novel supplement modified different antioxidant, metabolic and inflammatory pathways, improved energy homeostasis and the inflammatory state, and consequently alleviated hepatic steatosis.

Key words: Supplement, Silymarin, Prebiotic, Obese, Mice, Steatosis, Inflammation, Mitochondrial biogenesis