In a study recently published in American Journal of Clinical Nutrition, Finnish and French researchers aimed to elucidate parts of the underlying mechanisms of the health effects associated with high intake of whole grain rye. Metabolites circulating in the blood were investigated in a human intervention study using untargeted metabolomics.
Fifteen adults consumed whole grain rye bread or refined wheat bread enriched with fermented rye bran during four weeks. The four weeks of rye consumption were followed by four weeks of refined wheat bread consumption. Fasting plasma samples drawn after each of the two periods were compared regarding the subjects’ metabolic profiles. Plasma concentration of five endogenous metabolites was identified to be associated with whole grain rye intake, of which serotonin and taurine were two that both decreased after the whole grain rye period.
To test a hypothesis of altered biosynthesis of serotonin as a response to increased intake of cereal fiber, mice were fed a high fat diet supplemented with either rye bran, wheat aleurone or cellulose during nine weeks. Concordantly, lower levels of serotonin were found in the gut after consumption of rye bran or wheat aleurone compared to cellulose.
The results suggest that serotonin could be a possible link between whole grain consumption and its associated health effects.
Read more here