Dietary fibre-rich resistant starches promote ammonia detoxification in the human colon as measured by lactose-[¹5N2]ureide.

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-[(15)N2]ureide ((15)N-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 (15)N-LU, urine and faeces were collected over 48 and 72 h, respectively, whereas blood was collected after 6 h. The (15)N-abundances were measured by isotope ratio mass spectrometry. In comparison to the dry run, supplementation with RS significantly lowered renal (15)N-excretion (dry run: 43.2%, FP: 34.6%, WPS: 37.9%, HAMS: 36.4%) as well as the corresponding (15)NH3-excretion (dry run: 0.08%, FP: 0.06%, HAMS: 0.05%), clearly indicating a reduced colonic nitrogen generation at high dietary fibre intake.

Preclinical pharmacokinetic evaluation and metabolites identification of methyl salicylate-2-O-ß-d-lactoside in rats using LC-MS/MS and Q-TOF-MS methods.

Methyl salicylate-2-O-ß-d-lactoside (MSL) is a natural salicylate derivative from the traditional Chinese medicine of Gaultheria yunnanensis (Franch.) Rehder (G. yunnanensis). As a non-steroidal anti-inflammatory drug (NSAID), MSL exerts a significant anti-arthritis effect but hardly has any gastrointestinal toxicity. In this paper, the pharmacokinetics, distribution, excretion and identification of MSL and its metabolites are described following rat oral and intravenous administration. The biological samples were quantified by UPLC-MS/MS and the metabolites in urine and feces were identified by using Q-TOF-MS. These results will support future investigations leading to clinical development of this drug.

The nutriceutical bovine colostrum truncates the increase in gut permeability caused by heavy exercise in athletes.

Heavy exercise causes gut symptoms and, in extreme cases, "heat stroke" partially due to increased intestinal permeability of luminal toxins. We examined bovine colostrum, a natural source of growth factors, as a potential moderator of such effects. Twelve volunteers completed a double-blind, placebo-controlled, crossover protocol (14 days colostrum/placebo) prior to standardized exercise. Gut permeability utilized 5 h urinary lactulose-to-rhamnose ratios. In vitro studies (T84, HT29, NCM460 human colon cell lines) examined colostrum effects on temperature-induced apoptosis (active caspase-3 and 9, Baxα, Bcl-2), heat shock protein 70 (HSP70) expression and epithelial electrical resistance. In both study arms, exercise increased blood lactate, heart rate, core temperature (mean 1.4°C rise) by similar amounts. Gut hormone profiles were similar in both arms although GLP-1 levels rose following exercise in the placebo but not the colostrum arm (P = 0.026). Intestinal permeability in the placebo arm increased 2.5-fold following exercise (0.38 ± 0.012 baseline, to 0.92 ± 0.014, P < 0.01), whereas colostrum truncated rise by 80% (0.38 ± 0.012 baseline to 0.49 ± 0.017) following exercise. In vitro apoptosis increased by 47-65% in response to increasing temperature by 2°C. This effect was truncated by 60% if colostrum was present (all P < 0.01). Similar results were obtained examining epithelial resistance (colostrum truncated temperature-induced fall in resistance by 64%, P < 0.01). Colostrum increased HSP70 expression at both 37 and 39°C (P < 0.001) and was truncated by addition of an EGF receptor-neutralizing antibody. Temperature-induced increase in Baxα and reduction in Bcl-2 was partially reversed by presence of colostrum. Colostrum may have value in enhancing athletic performance and preventing heat stroke.

The effect of pre- and probiotics on the colonic ammonia metabolism in humans as measured by lactose-[¹5N2]ureide.

BACKGROUND: The evaluation of ammonia detoxification by pre- and probiotics by means of colonic lactose-[(15)N(2)]ureide ((15)N-LU) degradation is of great interest both scientifically and in terms of nutrition physiology. OBJECTIVE: Pre- and probiotics were supplemented in healthy adults to evaluate the effect of the ammonia metabolism in the human colon by means of (15)N-LU. METHODS: A total of 14 participants aged 20-28 years daily received a regular diet either without (no treatment) or with supplementation of 30 g fibre of potatoes (FPs), 30 g wrinkle pea starch (WPS, resistant starch content: 12 and 70%, respectively) and 375 g Lactobacillus acidophilus (LC1) yoghurt, over a 10-day period in a randomised order. After 1 week, 5.7 mg/kg body weight (15)N-LU was administered together with breakfast. A venous blood sample was taken after 6 h. Urine and faeces were collected over a period of 48 and 72 h, respectively. The (15)N abundances were measured by isotope ratio mass spectrometry. RESULTS: The mean renal (15)N-excretion differed significantly between the supplementation of FP and no treatment (32.5 versus 46.3%, P=0.034), FP and LC1 (32.5 versus 51.6%, P=0.001), and WPS and LC1 (38.5 versus 51.6%, P=0.048). The mean faecal (15)N-excretion amounted to 42.7% (no treatment), 59.7% (FP), 41.8% (WPS) and 44.0% (LC1). In comparison with no treatment, the urinary (15)NH(3)-enrichment was significantly decreased at 16 h after FP supplementation. CONCLUSION: The prebiotic intake of FP and WPS lowered the colonic generation and the renal excretion of toxic (15)NH(3), respectively, when using (15)N-LU as a xenobiotic marker.