In-vitro Prebiotic Activity of Grape Seed Flour Highly Rich in Flavonoid and Dietary Fiber

Interactions between lactic acid bacteria (LAB) and dietary polyphenols are not fully understood. This study determined the prebiotic effects of grape seed flour (GSF, a byproduct of wine making) and their polyphenol extracts (GSE) on the growth of 10 strains of probiotic LAB recently isolated from the kefir and pathogenic Clostridium perfringens. Growth rate of the LAB, Leuconostoc mesenteroides DH 1608, was the highest among 10 strains of LAB when cultivated with GSF. GSE, containing an equivalent amount of polyphenol in GSF, also promoted the growth of L. mesenteroides DH 1608 but at a lower rate compared to GSF. Growth of C. perfringens decreased significantly at 10 mg/mL of GSF, but GSE did not affect the growth. In conclusion, GSF may be a useful prebiotic dietary supplement due to its selective antimicrobial capacity via stimulation of probiotic bacteria and inhibition of pathogenic bacteria. A symbiotic combination of selected lactic acid bacteria and GSF may improve gut health.