Sniff some citrus, like a lemon wedge. The Smell & Taste Treatment and Research Foundation says it can calm a queasy stomach in a minute… Because the scent goes right to the brain’s nausea center and calms it down. You can also sip some hot water with lemon. Lemon juice contains a compound which triggers white blood cells to attack invading germs. So, if there’s bad bacteria in your gut, your white blood cells will tamp it down.