Application of NMR-based metabonomics suggests a relationship between betaine absorption and elevated creatine plasma concentrations in catheterised sows.

The objective of the present explorative study was to determine the absorption dynamics when feeding diets varying in types and levels of dietary fibre in a catheterised animal model. A total of six sows were fed a diet low in fibre (LF), a diet high in soluble fibre and a diet high in insoluble fibre in a repeated 3 × 3 cross-over design. Plasma samples were collected from the mesenteric artery and the portal vein to determine different absorption phases by ¹H NMR spectroscopy-based metabonomics. Time profiles were determined for plasma levels of specific metabolites and for the absorption of these metabolites from the small intestine. The LF diet resulted in a higher betaine concentration in the blood than the two high-fibre diets (P=0·008). This leads to higher plasma concentrations of methionine (P=0·0028) and creatine (P=0·020) of endogenous origin. In conclusion, the use of NMR spectroscopy for measuring nutrient uptake in the present study elucidated the relationship between betaine uptake and elevated creatine plasma concentrations.