Pomegranate peel extract shows prebiotic potential

Polyphenol-rich extracts from pomegranate peel may selectively enhance the growth of potentially beneficial gut bacteria, suggesting prebiotic activity for the extract, says a new study.

Scientists from the leading prebiotic research lab of Dr Patrice Cani and Dr Nathalie Delzenne at the Universite catholique de Louvain in Belgium report that consumption of a pomegranate peel extract was associated with increases in bifidobacteria in the intestine.

Results published in the British Journal of Nutrition also indicate  that the polyphenol-rich extract was associated with reductions in total and LDL cholesterol levels, as well as a reduction in the pro-inflammatory markers in the colon associated with co-consumption with a high-fat diet.

“Although mechanistic studies are needed in order to determine which bioactive constituent(s) or metabolite(s) coming from the gut bacteria were responsible for these effects, our results suggest that pomegranate peel extract can confer positive health impacts associated with gut microbiota modulation and may be a natural alternative in the prevention of obesity and cardiovascular disease,” wrote the researchers.

Prebiotics are defined as: "Non-digestible substances that provide a beneficial physiological effect on the host by selectively stimulating the favorable growth or activity of a limited number of indigenous bacteria".

Study details

The Louvain-based researchers used lab mice and fed them a high diet with or without a pomegranate peel extract at a daily dose of 6 milligrams for four weeks.

Results showed a s significant increase in bifidobacteria levels, but no changes for body weight gain or blood levels of inflammatory markers.

Improvements in cholesterol levels were accompanied by a counter-action of “high fat-induced expression of inflammatory markers both in the colon and the visceral adipose tissue”, they said.

“Together, these findings support that pomegranate constitutes a promising food in the control of atherogenic and inflammatory disorders associated with diet-induced obesity,” wrote the researchers.

“Knowing the poor bioavailability of pomegranate polyphenols, its bifidogenic effect observed after pomegranate peel extract consumption suggests the involvement of the gut microbiota in the management of host metabolism by polyphenolic compounds present in pomegranate.”

Source: British Journal of Nutrition

Published online ahead of print, doi: 10.1017/S0007114512002206

“Polyphenol-rich extract of pomegranate peel alleviates tissue inflammation and hypercholesterolaemia in high-fat diet-induced obese mice: potential implication of the gut microbiota”

Authors: A.M. Neyrinck, V.F. Van Hée, L.B. Bindels, F. De Backer, P.D. Cani, N.M. Delzenne