Lactose intolerance, lactose malabsorption and genetic predisposition to adult-type hypolactasia in patients after restorative proctocolectomy.

This study provides up-to-date findings on lactose malabsorption, lactose intolerance and genetic predisposition to adult-type hypolactasia in 72 patients after restorative proctocolectomy (RPC). The lactose malabsorption was assessed by hydrogen-methane breath test. Genetic predisposition to adult-type hypolactasia was assessed by detecting -13910T/C polymorphism in the lactase gene. Lactose intolerance was more frequent in UC (ulcerative colitis) patients than FAP (familial adenomatous polyposis) patients (77.5% vs. 55.2%; p=0.01). The C/C genotype of the lactase gene was observed in 39.1% subjects with no significant difference between UC and FAP patients. Lactose malabsorption occurred in 10.1% of subjects and almost only in patients with genetic predisposition, with the same frequency in UC and FAP patients.

Conjugated linoleic acid does not affect digestion and absorption of fat and starch-a randomized, double-blinded, placebo-controlled parallel study.

OBJECTIVE: Conjugated linoleic acid (CLA) is known as a potent agent for altering body weight and composition. However, its effect on the process of digestion is still unknown. The aim of this study has been to elucidate the effect of a 3-month supplementation with CLA on starch and fat digestion and absorption in humans. APPROACH: The study included 74 obese and overweight adults who were randomized to receive 3.0 g of CLA or sunflower oil as placebo daily for 3 months. Digestion and absorption of fat and starch was assessed using non-invasive breath tests with a stable 13C isotope (cumulative percentage dose recovery, CPDR) before and after the supplementation period. To exclude the effect of oxidation, in addition total energy expenditure (TTE) was measured by a 13C bicarbonate breath test. RESULTS: The changes in CPDR values (∆CPDR median 〈interquartile range〉) were no different between subjects from the CLA group and the placebo group (fat: -0.2 〈-9.1-4.1〉 versus 0.6 〈-7.0-8.0〉, p < 0.4796; starch: -1.3 〈-9.5-2.4〉 versus -1.0 〈-5.1-1.7〉, p < 0.5520, respectively). The incidence of negative and positive values of ∆CPDR was no different between groups [for fat: 53.1% versus 46.7%, RR 1.138, (95% CI 0.689-1.882) and for starch: 67.7% versus 56.7%, RR 1.195, (95% CI 0.804-1.777)]. The changes in TTE did not differ between the CLA and the placebo group (respectively 1 〈48; 267〉 versus -8 〈-120;93〉 kcal; p < 0.2728). CONCLUSION: Supplementation with CLA for 3 months did not affect fat and starch digestion assessed by 13C mixed triglyceride breath test and 13C starch breath test.

Green tea extract decreases starch digestion and absorption from a test meal in humans: a randomized, placebo-controlled crossover study.

Green tea is known worldwide for its beneficial effects on human health. However, objective data evaluating this influence in humans is scarce. The aim of the study was to assess the impact of green tea extract (GTE) on starch digestion and absorption. The study comprised of 28 healthy volunteers, aged 19 to 28 years. In all subjects, a starch (13)C breath test was performed twice. Subjects randomly ingested naturally (13)C-abundant cornflakes during the GTE test (GTE 4 g) or placebo test. The cumulative percentage dose recovery (CPDR) was significantly lower for the GTE test than for the placebo test (median [interquartile range]: 11.4% [5.5-15.5] vs. 16.1% [12.7-19.5]; p = 0.003). Likewise, CPDR expressed per hour was considerably lower in each point of the measurement. In conclusion, a single dose of green tea extract taken with a test meal decreases starch digestion and absorption.