Bioavailability of Phenolic Compounds in Bread

University of Parma15 enrolled

Overview

The consumption of wholemeal cereals has been associated with the reduction of several chronic diseases. The mechanisms behind these protective effects may be linked, besides dietary fiber and micronutrients, to an increased intake of phenolic compounds, mainly, hydroxycinnamates contained in the bran. Among bran fractions, aleurone usually contains the highest concentration of ferulic acid, principally contained as monomeric form and diferulic acid esters linked to arabinoxylans, representing the most relevant subclasses. The aim of the study was to evaluate the absorption of hydroxycinnamates by measuring the urinary excretion of phenolic metabolites in humans fed with two different kind of a commercial bread, as wholegrain bread and a white bread enriched with aleurone fraction. Moreover, the pharmacokinetics of the main phenolic compounds was also evaluated by measuring the circulating metabolites in plasma samples.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

SINGLE

Enrollment

Conditions

Dietary Modification

Interventions

Eligibility

Sex: ALLMin age: 18 YearsMax age: 30 YearsHealthy volunteers:

Medical Language ↔ Plain English

Inclusion Criteria: * BMI 18-25 kg/m2 Exclusion Criteria: * Pregnancy and breastfeeding * diagnosis of celiac disease * diagnosed methabolic diseases (diabetes and disorders of glycaemic control, hypertension, dyslipidemia) * sustained use of nutritional supplements of vitamins, in particular E and C, at the recruitment step * chronic pharmacological therapy * antibiotic therapy during the last 40 days

Outcomes

Primary Outcomes

Phenolic compound bioavailability in wholegrain bread compared with bread enriched with aleurone fraction (urine samples will be filtered and diluted and phenolic compound metabolites will be identified)

Volunteers will collect urine before consuming bread (T0) and for 48 hours after the consumption of the meal test, in each study arms. Urine samples will be collected and stored at -80°C until uHPLC/MS analysis. Prior analysis, urine samples will be filtered and diluted and phenolic compound metabolites will be identified. Expected Metabolites: Coumaric acid, Hydroxyphenylpropionic acid, Dihydroxyphenylacetic acid, Hippuric acid, Enterolactone, Enterodiol, Coumaric acid sulphate, Phenylpropionic acid sulphate, Vanillic acid sulphate, Hydroxyphenylpropionic acid sulphate, Ferulic acid sulphate, Dihydroferulic acid sulphate, Hydroxyphenylpropionic acid glucuronide, Ferulic acid glucuronide, Enterolactone sulphate, Enterodiol sulphate, Enterolactone glucuronide, Enterodiol glucuronide.

Time frame: 0h; 0-3h; 3-6h; 6-10h; 10-14h; 14-24h; 24-28h; 28-34h; 34-48h.

Secondary Outcomes

Phenolic compound pharmacokinetics in wholegrain bread compared with bread enriched with aleurone fraction (metabolites identified in Plasma samples that will be collected prior (T0) and after bread consumption in each study arms.)

Plasma samples will be collected prior (T0) and after bread consumption in each study arms. Expected Metabolites: Coumaric acid, Hydroxyphenylpropionic acid, Dihydroxyphenylacetic acid, Hippuric acid, Enterolactone, Enterodiol, Coumaric acid sulphate, Phenylpropionic acid sulphate, Vanillic acid sulphate, Hydroxyphenylpropionic acid sulphate, Ferulic acid sulphate, Dihydroferulic acid sulphate, Hydroxyphenylpropionic acid glucuronide, Ferulic acid glucuronide, Enterolactone sulphate, Enterodiol sulphate, Enterolactone glucuronide, Enterodiol glucuronide.

Time frame: 0h; 0.5h; 1h; 2h; 4h; 7h; 24h.