In order to survive, grow, and provoke a toxico-infection in the small intestine, B. cereus must adapt to changing pH values (the pH gradually increases from 2.0 to 4.0 in the stomach to 5.7e6.4 in the duodenum, 5.9e6.8 in the jejunum, and 7.3e7.7 in the ileum; [59]) and the carbohydrate and oxygen-limited conditions of the environment. In addition, the limited oxygen availability and highly reducing conditions of the small intestine (low oxidoreduction potential [ORP]; ~?150 mV) [60] strongly influencethe characterof cell metabolism.