title: L-rhamnose as a source of colonic propionate inhibits insulin secretion but does not influence measures of appetite or food intake.
abstract: Activation of free fatty acid receptor (FFAR)2 and FFAR3 via colonic short-chain fatty acids, particularly propionate, are postulated to explain observed inverse associations between dietary fiber intake and body weight. Propionate is reported as the predominant colonic fermentation product from l-rhamnose, a natural monosaccharide that resists digestion and absorption reaching the colon intact, while effects of long-chain inulin on appetite have not been extensively investigated. In this single-blind randomized crossover study, healthy unrestrained eaters (n = 13) ingested 25.5 g/d l-rhamnose, 22.4 g/d inulin or no supplement (control) alongside a standardized breakfast and lunch, following a 6-d run-in to investigate if appetite was inhibited. Postprandial qualitative appetite, breath hydrogen, and plasma glucose, insulin, triglycerides and non-esterified fatty acids were assessed for 420 min, then an ad libitum meal was provided. Significant treatment x time effects were found for postprandial insulin (P = 0.009) and non-esterified fatty acids (P = 0.046) with a significantly lower insulin response for l-rhamnose (P = 0.023) than control. No differences between treatments were found for quantitative and qualitative appetite measures, although significant treatment x time effects for meal desire (P = 0.008) and desire to eat sweet (P = 0.036) were found. Breath hydrogen was significantly higher with inulin (P = 0.001) and l-rhamnose (P = 0.009) than control, indicating colonic fermentation. These findings suggest l-rhamnose may inhibit postprandial insulin secretion, however neither l-rhamnose or inulin influenced appetite.
authors.affiliation: Diabetes and Nutritional Sciences Division, School of Medicine, King's College London, Franklin-Wilkins Building, London SE1 9NH, United Kingdom. Electronic address: julia.darzi@kcl.ac.uk.
authors.forename: Julia
authors.initials: J
authors.lastname: Darzi
authors.affiliation: Faculty of Medicine, Nutrition and Dietetics Research Group, Division of Diabetes, Endocrinology and Metabolism, Department of Investigative Medicine, Imperial College London, London W12 0NN, United Kingdom.
authors.forename: Gary S
authors.initials: GS
authors.lastname: Frost
authors.affiliation: Division of Computational and Systems Medicine, Department of Surgery and Cancer, Imperial College London, London SW7 2AZ, United Kingdom.
authors.forename: Jonathan R
authors.initials: JR
authors.lastname: Swann
authors.affiliation: Health Sciences Research Centre, Whitelands College, University of Roehampton, London SW15 5PU, United Kingdom.
authors.forename: Adele
authors.initials: A
authors.lastname: Costabile
authors.affiliation: Nutritional Sciences, University of Surrey, Leggett Building, Guildford, Surrey GU2 7WG, United Kingdom.
authors.forename: M Denise
authors.initials: MD
authors.lastname: Robertson
mesh_terms: D000293:Adolescent; D000328:Adult; D001066:Appetite / Q000187:drug effects*; D001786:Blood Glucose / Q000378:metabolism; D015992:Body Mass Index; D008076:Cholesterol, HDL / Q000097:blood; D008078:Cholesterol, LDL / Q000097:blood; D003106:Colon / Q000187:drug effects* / Q000378:metabolism; D018592:Cross-Over Studies; D004040:Dietary Carbohydrates / Q000008:administration & dosage; D004041:Dietary Fats / Q000008:administration & dosage; D004043:Dietary Fiber / Q000008:administration & dosage; D004044:Dietary Proteins / Q000008:administration & dosage; D019587:Dietary Supplements; D002149:Energy Intake; D005230:Fatty Acids, Nonesterified / Q000097:blood; D005260:Female; D052216:Glucagon-Like Peptide 1 / Q000378:metabolism; D006801:Humans; D007328:Insulin / Q000378:metabolism*; D007333:Insulin Resistance; D000078790:Insulin Secretion; D007444:Inulin / Q000008:administration & dosage; D008297:Male; D008875:Middle Aged; D019894:Peptide YY / Q000378:metabolism; D019518:Postprandial Period / Q000187:drug effects; D011422:Propionates / Q000097:blood*; D011956:Receptors, Cell Surface / Q000378:metabolism; D043562:Receptors, G-Protein-Coupled / Q000378:metabolism; D012210:Rhamnose / Q000008:administration & dosage*; D016037:Single-Blind Method; D055105:Waist Circumference; D055815:Young Adult
chemical_list: D001786:Blood Glucose; D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D004040:Dietary Carbohydrates; D004041:Dietary Fats; D004043:Dietary Fiber; D004044:Dietary Proteins; D005230:Fatty Acids, Nonesterified; D052216:Glucagon-Like Peptide 1; D007328:Insulin; D007444:Inulin; D019894:Peptide YY; D011422:Propionates; D011956:Receptors, Cell Surface; D043562:Receptors, G-Protein-Coupled; D012210:Rhamnose; C473103:FFAR2 protein, human; C106262:FFAR3 protein, human
keywords: Appetite; Inulin-type fructans; Postprandial insulin; Satiety; Short-chain fatty acids