Objectives: Butyric acid, synthesized via bacterial fermentation in colonic lumen, may play an important role in the nutrition of the colonic mucosa. Since disaccharides, especially lactose, are the principal dietary carbohydrates during infancy, it is important to determine if their fermentation is associated with butyric acid synthesis. The objective of this paper is to describe a newly developed stable isotope method for quantifying butyric acid synthesis in the colonic lumen and to demonstrate its application during cecal infusions of lactose and lactulose in piglets.
Methods: Nine piglets aged 21 to 30 days were studied during acute anesthesia. The 13C enrichment of butyric acid was monitored in the portal vein before and during a 120 minutes cecal infusion of [1–13C]-butyric acid and either unlabeled lactose (N = 4) or lactulose (N = 5).
Results: The luminal synthesis of BA (μmol x kg−1 x min−1) (Mean ± S.D.) was respectively 1.5 ± 0.9 and 1.2 ± 0.6 during lactulose and lactose infusion.
Conclusions: This study provides new quantitative data on in vivo butyric acid production in the mammalian colon.