Reduction of non-digestible oligosaccharides in soymilk: application of engineered lactic acid bacteria that produce alpha-galactosidase

Human consumption of soy-derived products has been limited by the presence of non-digestible oligosaccharides (NDO), such as the alpha-galactooligosaccharides raffinose and stachyose. Most mammals, including man, lack pancreatic alpha-galactosidase (alpha-Gal), which is necessary for the hydrolysis of these sugars. However, such NDO can be fermented by gas-producing microorganisms present in the cecum and large intestine, which in turn can induce flatulence and other gastrointestinal disorders in sensitive individuals.The use of microorganisms expressing alpha-Gal is a promising solution to the elimination of NDO before they reach the large intestine. In the present study, lactic acid bacteria engineered to degrade NDO have been constructed and are being used as a tool to evaluate this solution. The alpha-Gal structural genes from Lactobacillus plantarum ATCC8014 (previously characterized in our laboratory) and from guar have been cloned and expressed in Lactococcus lactis. The gene products were directed to different bacterial compartments to optimize their possible applications. The alpha-Gal-producing strains are being evaluated for their efficiency in degrading raffinose and stachyose: i) in soymilk fermentation when used as starters and ii) in situ in the upper gastrointestinal tract when administered to animals orally, as probiotic preparations. The expected outcomes and possible complications of this project are discussed.

Effects of dog regenerating liver cytosol on MPS function of rats with experimental liver injury / 中国病理生理杂志

Using the technique for measuring clearance rate of ~(125)I-microaggregated albumin(~(125)I-MAA), we investigated the effects of dog regenerating liver cytosol(DRLC) on the function of mononuclear phagocytic system (MPS) of rats with liver injury induced by D-galactosamine(D-GalN). The results showed that the clearance rate of ~(125)I-MAA from plasma in rats with liver injury was markedly inhibited, the half life(T_(1/2)) of ~(125)I-MAA was significantly prolonged(P

ANTI-HBV EFFECT OF GALACTOSIDES MODIFIED LAMIVUDINE TARGETED TO LIVER / 解放军医学杂志

The aim of the present study was to investigate the inhibitory effect of galactosides modified lamivudine (LA) on hepatitis B virus (HBV) and examine the liver targeting ability of lamivudine modified by galactosides in vitro and in vivo (mice). Lamivudine nanoparicles modified by galactosides (LAP GSLN) were prepared and delivered into 2.2.15 cells. After 10 days, hepatitis virus B e antigen (HBeAg) expression in 2.2.15 cells was detected by ELISA, and immune fluorescence levels of HBV DNA in the medium were examined by quantitative polymerase chain reaction (PCR). The cytotoxicity of LAP GSLN on 2.2.15 cells was observed as well. In the in vivo experiment, ten male mice were randomly divided into 2 groups: lap GSLN group (i.v.injection of LAP GSLN) and LA group (i.v.injection of LA). Lamivudine levels in serum, hepatic, renal, pulmonary, and splenic tissues were detected by reversed phase high performance liquid chromatography (RP HPLC). On the 6th day, the expression of HBeAg was found inhibited by LPA GSLN. HBV DNA replication was also inhibited by LAP GSLN on the 4th day. Hepatic LAP GSLN concentrations in LAP GSLN group were 3.3 fold higher that of the LA group. The above results suggested galactosides modified lamivudine could effectively inhibit the antigen expression and DNA replication of HBV, and it showed a high liver targeting ability in vivo .