Bitter breath, bad breath and old fart are not the precursors of liver cancer, but may be caused by gastritis and improper diet. 1. Gastritis: patients may suffer from bitter breath and bad breath with farting, which may be caused by Helicobacter pylori infection, while farting may be caused by insufficient gastrointestinal dynamics of patients with gastritis, which leads to food not being digested well, resulting in abdominal distension, nausea and vomiting, belching and other phenomena, thus gas production will increase. 2. Improper diet: people who eat meat for a long time, due to insufficient intake of fiber, gastrointestinal power is weakened, resulting in indigestion, this kind of people usually appear constipation, increased gas production, bitter breath and bad breath phenomenon. Gastritis patients can follow the doctor’s instructions through omeprazole and other drugs for treatment, while patients with improper diet to eat more light vegetables and fruits, a reasonable diet.