Phytic Acid Improves Hepatic Steatosis, Inflammation, and Oxidative Stress in High-Fat Diet (HFD)-Fed Mice by Modulating the Gut–Liver Axis

Nonalcoholic fatty liver disease (NAFLD) induced by obesity is a grave threat to human health. Phytic acid (PA) is a natural compound found in high-fiber diets, such as soybeans. This study investigated the effects and mechanisms of PA on obesity, hepatic lipid metabolism, and gut–liver axis homeostasis in high-fat diet (HFD)-fed mice. PA was observed to significantly inhibit obesity and alleviate liver steatosis in mice. PA improved HFD-induced liver inflammation, oxidative stress and fibrosis. Moreover, PA improved HFD-induced colonic inflammation, gut barrier damage and systemic inflammation in mice. Furthermore, PA effectively ameliorated the decreased diversity and gut microbiota composition in HFD-fed mice. Additionally, PA decreased the abundance of harmful bacteria Proteobacteria and Desulfovibrionaceae and increased the abundance of probiotic bacteria Muribaculaceae and Lachnospiraceae. Thus, PA is effective in restoring the homeostasis of the gut–liver axis. It further provides a theoretical basis for the prevention and treatment of NAFLD in patients with obesity by the rational intake of foods containing PA.