Effect of barley β-glucan on bile acid excretion and blood cholesterol
Research type
Research Study
Full title
A pilot study investigating the effect of barley β-glucan on faecal polydeoxycholic acid excretion in mildly hypocholesterolaemic adults
IRAS ID
209408
Contact name
Gary Frost
Contact email
Sponsor organisation
Joint Research Compliance Office, Imperial College London
Duration of Study in the UK
2 years, 0 months, 0 days
Research summary
Cardiovascular diseases, such as coronary heart disease (CHD) continue to be the single leading cause of death worldwide. In the UK alone, CHD is responsible for 73,000 deaths annually. As high plasma cholesterol is reported to be responsible for an appreciable percentage of global CVD cases, maintaining lower plasma cholesterol levels has become a priority in having a healthy life.
The cholesterol-lowering effects and CHD risk reduction potential of increased intake of soluble fibres (SF) such as β-glucans are well documented; existing literature strongly suggests that SF alter the metabolism of bile acids, causing a greater loss of bile acids in faeces. The loss of bile acids results in a compensatory breakdown of cholesterol into bile acids by the liver, leading to a reduction of the body’s cholesterol levels. However, the mechanisms by which SF successfully disrupt bile acid metabolism are poorly understood. Based on evidence in literature, we hypothesize SF promote the polymerization (conversion to larger molecules) of bile acids by resident microbiota in the colon. These larger bile acid molecules are excreted from the body leading to an increased loss of bile acids and breakdown of cholesterol. Exploiting this pathway presents an attractive mechanism for controlling blood cholesterol levels through dietary manipulation.
This study aims to investigate the effects of a fibre-based intervention on the polymerization of bile acids in healthy adults with slightly raised cholesterol levels. The study is a crossover randomised design with two arms, low and high β-glucan phases. Each phase will last 5 weeks separated by a 5-week washout period.
Results from this study will provide mechanistic understanding of the effect of diet on a major societal disorder as well as contribute to the development of effective dietary approaches to combat CHD/CVD and its associated burden on health and finances.REC name
London - Surrey Borders Research Ethics Committee
REC reference
17/LO/0088
Date of REC Opinion
8 Mar 2017
REC opinion
Further Information Favourable Opinion