Whole grain can contribute to health by changing intestinal serotonin production - ScienceBlog.comThe consumption of wholegrain rye led to, among other things, significantly lower serotonin concentrations when compared to consumption of low-fibre wheat bread. The researchers also tested in mice whether the addition of cereal fibre to the diet changes serotonin production in the intestine. The diet of the mice was supplemented for nine weeks with rye bran, wheat bran or cellulose flour. The mice receiving rye or wheat bran had significantly lower serotonin in their colon. Serotonin is best known as a neurotransmitter in the brain. However, serotonin produced by the intestines remains separated from the brain, serving various peripheral functions including modulation of gut’s motility. Increased blood serotonin has also been associated with high blood glucose levels.