Metabolomics reveals the metabolic shifts following an intervention with rye bread in postmenopausal women- a randomized control trial
1 Department of Chemistry, Swedish University of Agricultural Sciences, P.O. Box 7015, Uppsala, SE, 75007, Sweden
2 Department of Food Science, Swedish University of Agricultural Sciences, Uppsala, Sweden
3 Department of Public Health and Clinical Nutrition, Clinical Nutrition, Food and Health Research Centre, University of Eastern Finland, Kuopio Campus, P.O. Box 1627, Kuopio, FIN 70211, Finland
4 VTT Technical Research Centre of Finland, P.O. Box 1000, Tietotie 2, Espoo, FI-02044, Finland
5 City of Kuopio, Health Care Services, Health Care Unit, Suokatu 40 B, Kuopio, FI-70110, Finland
Nutrition Journal 2012, 11:88 doi:10.1186/1475-2891-11-88Published: 22 October 2012
Epidemiological studies have consistently shown that whole grain (WG) cereals can protect against the development of chronic diseases, but the underlying mechanism is not fully understood. Among WG products, WG rye is considered even more potent because of its unique discrepancy in postprandial insulin and glucose responses known as the rye factor. In this study, an NMR-based metabolomics approach was applied to study the metabolic effects of WG rye as a tool to determine the beneficial effects of WG rye on human health.
Thirty-three postmenopausal Finnish women with elevated serum total cholesterol (5.0-8.5 mmol/L) and BMI of 20–33 kg/m2 consumed a minimum of 20% of their daily energy intake as high fiber WG rye bread (RB) or refined wheat bread (WB) in a randomized, controlled, crossover design with two 8-wk intervention periods separated by an 8-wk washout period. At the end of each intervention period, fasting serum was collected for NMR-based metabolomics and the analysis of cholesterol fractions. Multilevel partial least squares discriminant analysis was used for paired comparisons of multivariate data.
The metabolomics analysis of serum showed lower leucine and isoleucine and higher betaine and N,N-dimethylglycine levels after RB than WB intake. To further investigate the metabolic effects of RB, the serum cholesterol fractions were measured. Total- and LDL-cholesterol levels were higher after RB intake than after WB (p<0.05).
This study revealed favorable shifts in branched amino acid and single carbon metabolism and an unfavorable shift in serum cholesterol levels after RB intake in postmenopausal women, which should be considered for evaluating health beneficial effects of rye products.