Unwanted side effects: Oat beta-glucan beats out plant sterols in cholesterol-lowering study
Research from the APC Microbiome Institute in Cork, Ireland, tested the effectiveness of plant sterol esters and beta glucans for cholesterol – an area where both have been well documented to have beneficial effects. However, the new mouse study unearthed some revealing side effects on the gut microbiota and metabolism.
Writing in the journal Microbiome, the Irish team reported that consumption of oat beta glucan not only lowered blood cholesterol in mice, but also help keep body weight down and benefited the gut microbiota, the community of microbes living in the intestines.
Furthermore, beta glucan positively impacted the composition and functionality of the gut microbiota – acting as a prebiotic, and increasing bacteria in the gut of the mice.
Meanwhile, plant sterol esters were found to be the more effective in lowering blood cholesterol and helping to avoid plaque build-up, but caused the greatest weight gains and adversely affected the gut microbiota composition of the mice.
Eating porridge regularly was found to be a good way to ensure the heart and gut health benefits of consuming oat beta glucan were realised, the study added.
“These results show we need to consider effects on the microbiome when treating cardiovascular disease through either food or medication,” Professor Catherine Stanton, leader of the research at the APC Microbiome said.
Speaking to NutraIngredients, Stanton explained how this trial differed from previous trials in this area: “Other studies have previously demonstrated the benefits of oat beta glucan and plant sterol esters for heart health and prevention of plaque deposits. But previous studies have not really taken into action the impact of the gut microbiome.”
“The message is to take porridge regularly to reduce your risk of cardiovascular disease whilst also protecting your gut microbiota,” she commented.
Mice were fed a high fat diet together with either one of the two food supplements or the statin Atorvastatin over a period of 24 weeks. The mice used were susceptible to the build-up of cholesterol in their arteries.
Oat beta glucan altered both the composition and functionality of the gut microbiota. Ii particular, the level of butyrate, a type of fatty acid produced by gut bacteria which has been previously shown to protect against diet-induced obesity in mice, was elevated in this study.
Beta glucan also acted as a prebiotic, and increased bacteria in the gut which are being explored by others to treat obesity.
Plant sterol esters, in contracts, resulted in weight and adiposity gains and adversely affected the gut microbiota composition of the mice.
“The current study suggests gut microbes as an additional important player in the interface between our environment and cardiovascular health,” said study co-author Professor Noel Caplice “Specifically it shows that certain foods may facilitate weight loss as well as encouraging growth of beneficial microbes in our intestines.”
Caplice added that understanding this balance between food, gut bacteria and health may have implications for development of a range of new food and therapeutic products targeting cardiovascular disease – which is principal cause of death in men and women in the developed world.
“As a population, we all consume a range of food and pharmaceutical ingredients which impact directly on our health,” commented first author Dr Paul Ryan. “This study now highlights the importance of considering interactions between the gut microbiota and novel supplements or therapeutics, which may indirectly affect our health.”
What happens next
The institute is now developing its own range of probiotics and food ingredients to help with heart health, which they are testing on animals.
“We are very interested in looking at the link between the microbiota and how they impact on heath health and obesity,” said Stanton.
“We don’t want to just demonstrate that they [probiotics and food ingredients] work. We need to know how they work and the mechanism of the interaction between microbes and health and the whole cardiovascular system.”
Published online , Open Access, doi: 10.1186/s40168-017-0246-x
“Microbiome and metabolome modifying effects of several cardiovascular disease interventions in apo-E−/− mice”
Authors: Paul M. Ryan, et al
** This article was updated on 19th April after it was pointed out that we had incorrectly said plant stanol esters were used in the APC study. The research actually used plant sterol esters. NutraIngredients apologise for the mistake.