Abstract
Three resistant starches (RSs), namely fibre of potatoes (FP), wrinkle pea starch (WPS), and high amylose maize starch (HAMS) with different dietary fibre contents, were supplemented in adults to evaluate their effects on urinary nitrogen and ammonia excretion as well as on faecal nitrogen excretion by means of lactose-[15N2]ureide (15N-LU) degradation. Twenty subjects received a regular diet either without or with the supplementation of FP, WPS, and HAMS in a randomized order. After administration of 15N-LU, urine and faeces were collected over 48 and 72 h, respectively, whereas blood was collected after 6 h. The 15N-abundances were measured by isotope ratio mass spectrometry. In comparison to the dry run, supplementation with RS significantly lowered renal 15N-excretion (dry run: 43.2 %, FP: 34.6 %, WPS: 37.9 %, HAMS: 36.4 %) as well as the corresponding 15NH3-excretion (dry run: 0.08 %, FP: 0.06 %, HAMS: 0.05 %), clearly indicating a reduced colonic nitrogen generation at high dietary fibre intake.
Disclosure statement
No potential conflict of interest was reported by the author.