Characterization and prebiotic activity of aqueous extract and indigestible polysaccharide from Anoectochilus formosanus.
Anoectochilus formosanus  (Orchidaceae) is a folk medicine in Asia. This study investigated the in vivo and in vitro prebiotic effects of an aqueous extract of A. formosanus (SAEAF) and of an indigestible polysaccharide (AFP) isolated from SAEAF. Chemical analyses showed AFP was mainly composed of arabinogalactan type II (AG-II), with an average molecular weight of 29 kDa. Following 4 weeks of oral administration to rats, SAEAF exhibited prebiotic effects including a decrease in cecum pH and increases of calcium absorption and fecal bifidobacteria. Furthermore, through a bioactivity-guided separation strategy, AFP was proven to be a bifidogenic component in vitro fecal strains fermentation and in vivo administration to mice. In RT-PCR analysis of  Bifidobacterium , AFP increased the expression of ABC transporter related to nutrient uptake. Thus, AFP, a polysaccharide from A. formosanus, was demonstrated to be a prebiotic that has a positive health effect on gut microbiota.
Institute of Food Science and Technology, National Taiwan University, Taipei, Taiwan, Republic of China.
Li-Chan
LC
Yang
Wen-Chuan
WC
Lin
Ting-Jang
TJ
Lu
D000042:Absorption; D000818:Animals; D001644:Bifidobacterium / Q000254:growth & development; D002118:Calcium / Q000378:metabolism; D002236:Carbohydrate Conformation; D002432:Cecum / Q000737:chemistry; D005243:Feces / Q000382:microbiology; D005285:Fermentation; D005685:Galactans / Q000032:analysis; D006863:Hydrogen-Ion Concentration; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D029595:Orchidaceae / Q000737:chemistry*; D010936:Plant Extracts / Q000008:administration & dosage* / Q000737:chemistry*; D011134:Polysaccharides / Q000008:administration & dosage* / Q000032:analysis / Q000737:chemistry*; D056692:Prebiotics; D051381:Rats; D017208:Rats, Wistar
D005685:Galactans; D010936:Plant Extracts; D011134:Polysaccharides; D056692:Prebiotics; C005653:arabinogalactan; D002118:Calcium