Antihypertensive activity of blueberries fermented by Lactobacillus plantarum DSM 15313 and effects on the gut microbiota in healthy rats

Abstract

The aim of the present animal study was to examine the anti-hypertensive capacity of two probiotic products combining blueberries and the tannase producing probiotic bacteria Lactobacillus plantarum DSM 15313 and to investigate if such an effect is linked to a change in the gut microbiota. Male Sprague Dawley rats were randomly divided into six groups of nine each. Three groups of the animals were treated with N(G)-nitro-L-arginine methyl ester (L-NAME) in the drinking water (40 mg/L) to induce a hypertensive state, and the other three groups were not treated with L-NAME (healthy rats). Two blueberry products differing in their phenolic acid content were tested and each rat received 2 g/day of the fermented blueberry powders for 4 weeks. The effects of the study products on the blood pressure, blood lipids, inflammatory markers, organ weights as well as caecal microbiota of the healthy (non-L-NAME-treated) rats were analyzed. After four weeks, healthy rats consuming freeze dried fermented blueberries with probiotics had a significant reduction in blood pressure compared to the control rats. In rats with L-NAME induced hypertension there was a significant reduction of the blood pressure after two weeks treatment. The probiotic product with a higher content of phenolic acids reduced ALAT in the healthy rats. Furthermore, ingestion of the probiotic blueberry products resulted in changes of the gut microbiota in the healthy rats. Blueberries fermented with the tannase producing bacteria L. plantarum DSM 15313 have anti-hypertensive properties and may reduce the risk for cardiovascular diseases.