Eleutherine americana as a growth promotor for infant intestinal microbiota

Abstract

Eleutherine americana extract and its oligosaccharides extract were demonstrated for their growth-promoting activities on mixed infant intestinal microbiota and individual bacterial species including Bacteroides, bifidobacteria, clostridia, and lactobacilli. Fermentation of all the substrates resulted in about 1-2 log increase in the numbers of bifidobacteria belonging to the dominant infant gut microbiota. The highest levels of the bacterial populations were resulted from the oligosaccharides extract. The oligosaccharides extract stimulated the growth of bifidobacteria in mixed and individual populations by increasing their numbers from 9.63 to 12.08 and 5.80 to 8.85 log cfu/ml, respectively within 48 h. In addition, Bacteroides populations were enhanced by fermentation of E. americana extract. Increase in lactobacilli level was observed from fermentation by a single bacterial species, but not from the mixed cultures. Fermentation of the extract, oligosaccharides extract, and commercial fructo-oligosaccharides by both mixed and individual intestinal microbiota resulted in increase in the production of short chain fatty acids. Acetic acid production was predominant, followed by lactic acid and minor amount of propionic and butyric acids. The highest production of acetic acid was resulted from the oligosaccharides extract. Increase in the acetic acid in mixed and individual species of bifidobacterial populations ranged from 1.21 to 34.26 and 1.02-25.21 mM, respectively. This study showed that E. americana can be considered as a potential prebiotic which may be supplemented as an ingredient in functional foods.