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Pilot Study of Novel Intermittent Fasting Effects on Metabolomic and Trimethylamine N-oxide Changes During 24-hour Water-Only Fasting in the FEELGOOD Trial.
Washburn, RL, Cox, JE, Muhlestein, JB, May, HT, Carlquist, JF, Le, VT, Anderson, JL, Horne, BD
Nutrients. 2019;11(2)
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Intermittent fasting – the practice of significantly cutting food intake on a number of days and eating normally on others – has been connected with numerous health benefits such as weight loss, reduced risk of heart disease and Type 2 diabetes, longer life span and improved quality of life. This randomised, cross over trial of 30 healthy individuals sought to evaluate the effects of fasting on Trimethylamine N-oxide (TMAO) levels, a substance produced in humans by intestinal bacteria and associated with heart disease in humans. 74 other metabolites were also measured. Subjects were randomised to a ‘fasting first’ group, with water-only intake for 24 hours, followed by 24 hours of eating freely, or an ‘eating first’ group, before crossing over. Measurements were made at baseline, at the end of the fasting day and at the end of the eating day. The authors found that TMAO levels decreased on the fasting day compared to the eating day. These levels returned to pre-fasting levels within 24 hours. 30 of the other 74 metabolic markers, including some amino acids and fatty acids, achieved significant changes between fasting and eating days. The authors suggest that consistent and repeated episodes of intermittent fasting may lead to improved health and reduced risk of heart disease and diabetes. Nutrition Practitioners may wish to consider intermittent fasting when working with clients with these conditions.
Abstract
Intermittent fasting (IF) has been connected with health benefits such as weight loss, lower risk of coronary artery disease (CAD) and diabetes, increased longevity, and improved quality of life. However, the mechanisms of these IF benefits in humans require further investigation. This study sought to elucidate some of these mechanisms through secondary analyses of the Fasting and ExprEssion of Longevity Genes during fOOD abstinence (FEELGOOD) trial, in which apparently healthy participants were randomized in a Latin square design to a 24-h water-only fast and a 24-h ad libitum fed day. Two pathways were investigated, with trimethylamine N-oxide (TMAO) levels measured due to their association with elevated risk of CAD, along with conductance of a broad panel of metabolic analytes. Measurements were made at baseline, at the end of the fasting day, and at the end of the fed day. A fasting mean of 14.3 ng in TMAO was found versus the baseline mean of 27.1 ng with p = 0.019, although TMAO levels returned to baseline on refeeding. Further, acute alterations in levels of proline, tyrosine, galactitol, and urea plasma levels were observed along with changes in 24 other metabolites during the fasting period. These acute changes reveal short-term mechanisms which, with consistent repeated episodes of IF, may lead to improved health and reduced risk of CAD and diabetes.
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Randomised clinical study: Aspergillus niger-derived enzyme digests gluten in the stomach of healthy volunteers.
Salden, BN, Monserrat, V, Troost, FJ, Bruins, MJ, Edens, L, Bartholomé, R, Haenen, GR, Winkens, B, Koning, F, Masclee, AA
Alimentary pharmacology & therapeutics. 2015;42(3):273-85
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Gluten is high in proline, an amino acid that is not naturally broken down in the human gastrointestinal tract. In patients with coeliac disease, proline-rich gluten reaches the small intestine and triggers an abnormal immune response, causing inflammation and microvilli damage. The aim of this randomised study was to test the efficacy of Aspergillus niger prolyl endoprotease (AN-PEP) on gluten degradation. AN-PEP belongs to a family of enzymes that has been previously known to break down proline in vitro. The study included 12 healthy volunteers aged 18-45 who were administered a low or high calorie meal containing 4.0g of gluten protein, with AN-PEP or placebo into the stomach. The findings of this study showed that AN-PEP significantly enhanced gluten digestion in the stomach before entering the duodenum of healthy volunteers. Based on this study, the authors conclude that AN-PEP is a promising option for degrading inadvertent dietary gluten consumption, and should be evaluated in target populations.
Abstract
BACKGROUND Aspergillus niger prolyl endoprotease (AN-PEP) efficiently degrades gluten molecules into non-immunogenic peptides in vitro. AIM: To assess the efficacy of AN-PEP on gluten degradation in a low and high calorie meal in healthy subjects. METHODS In this randomised, double-blind, placebo-controlled, cross-over study 12 healthy volunteers attended to four test days. A liquid low or high calorie meal (4 g gluten) with AN-PEP or placebo was administered into the stomach. Via a triple-lumen catheter gastric and duodenal aspirates were sampled, and polyethylene glycol (PEG)-3350 was continuously infused. Acetaminophen in the meals tracked gastric emptying time. Gastric and duodenal samples were used to calculate 240-min area under the curve (AUC0-240 min ) of ?-gliadin concentrations. Absolute ?-gliadin AUC0-240 min was calculated using duodenal PEG-3350 concentrations. RESULTS AN-PEP lowered α-gliadin concentration AUC0-240 min, compared to placebo, from low and high calorie meals in stomach (low: 35 vs. 389 μg × min/mL; high: 53 vs. 386 μg × min/mL; P < 0.001) and duodenum (low: 7 vs. 168 μg × min/mL; high: 4 vs. 32 μg × min/mL; P < 0.001) and absolute α-gliadin AUC0-240 min in the duodenum from low (2813 vs. 31 952 μg × min; P < 0.001) and high (2553 vs. 13 095 μg × min; P = 0.013) calorie meals. In the placebo group, the high compared to low calorie meal slowed gastric emptying and lowered the duodenal α-gliadin concentration AUC0-240 min (32 vs. 168 μg × min/mL; P = 0.001). CONCLUSIONS AN-PEP significantly enhanced gluten digestion in the stomach of healthy volunteers. Increasing caloric density prolonged gastric residence time of the meal. Since AN-PEP already degraded most gluten from low calorie meals, no incremental effect was observed by increasing meal caloric density. ClinicalTrials.gov, Number: NCT01335503; www.trialregister.nl, Number: NTR2780.