Freeze-dried jabuticaba peel and seed to C57BL/6 J mice with NAFLD reduced weight gain, glucose intolerance, glucose levels, insulin levels, HOMA-IR index, and total cholesterol, LDL-c level, IL-6 and TNF-α levels, improved liver function, reduced steatosis and fibrosis, improved gut barrier (mucin and claudin), and reduced LPS plasma concentration. It reduced Firmicutes to Bacteroidetes ratio and the abundance of Bifidobacteriaceae, Mogibacteriaceae, Christensenellaceae, Clostridiaceae, Dehalobacteriaceae, Peptococcaceae, Peptostreptococcaceae, and Ruminococcaceae in the feces. The gene discussed is MUC5AC; the disease is steatosis.