THE EFFECTS OF INTESTINAL SULFATE-REDUCING BACTERIA ON COGNITIVE BEHAVIOR AND INTESTINAL TRANSIT IN MICE by NATHANIEL RITZ

This research reports the effects of two metabolic groups of bacteria on physiological activity and cognitive function in C57BL/6 mice. In one experiment, the mice on a diet supplemented with red kidney bean for 24 hr were able to complete an eight-arm radial learning maze in a shorter time than mice on a diet without red kidney beans. The median time required for mice to complete the maze when fed red kidney beans was 118 sec while the median time for mice on standard diet to finish the maze was 270 sec. Based on the cycle threshold values when using universal bacterial primers on mid-small intestine contents, the mice fed the red kidney bean diet had a greater number of gene copies of bacteria as compared to the intestinal contents of mice receiving the standard diet. The introduction of 1 X 10 9 live cells of Desulfovibrio vulgaris into the stomach of mice by gavage resulted in reducing the rate at which contents in the small intestine traveled and impaired cognitive function as assessed using the eight arm radial learning maze. The impaired performance of mice in the learning maze occurred only with