Abstract
The growth responses of a variety of human intestinal bacteria to extracts of Panax ginseng and five other oriental medicinal Araliaceae were evaluated in vitro. The extracts enhanced the growth of Bifidobacterium breve and B. longum in media with or without carbon sources, suggesting that bifidus factor(s) might be involved in the phenomenon. This effect was most pronounced with water extract of P. ginseng, the growth of 27 bifidobacteria strains belonging to B. adolescentis, B. longum, B. breve and B. infantis being greatly stimulated, whereas seven B. bifidum strains and other bacteria such as Clostridia and Escherichia coli had little or no ability to utilise it for growth. Methanol extracts of P. ginseng were found to selectively inhibit growth of various Clostridia including C. perfringens and C. paraputrificum, but this effect was not observed on other bacteria including bifidobacteria. These results may be an indication of at least one of the pharmacological actions of P. ginseng as an adaptogen.