Study On Probiotic Effects Of The Lactic Acid Bacteria From Traditional Dairy Products In Inner Mongolia

In this study, probiotics were screened from 38 strains of lactic acid bacteria(LAB) isolated from dairy and dairy products from countysides of Inner Mongolia,and their probiotic functions was studied.In vitro screening experiments of probiotics included tolerance in pH3 and 0.3% bile salt, sensitivity to 19 common drugs, adherence to HT-29 cell and inhibition of their fermentation supernatant to the indicator. The results showed that after acclimated, 9 strains of Enterococcus and 12 strains of Lactobacillus plantarum in all strains had acid resistance and bile tolerance, their survival rate in 0.3% bile were over 45% and growth rate in pH3 were over 60%, even 100%. Except that WZ38-2 and WZ26-1, 9 strains of Enterococcus showed resistance to most of the drugs, while 12 strains of Lactobacillus plantarum were only resistant to glycopeptide, quinolones, penicillin and polymyxin B. All of lactic acid bacteria had the different ability of adherence to HT-29 cell, the average adhersion level of Lactobacillus plantarum (2.9 bacteria/cell) were significantly higher than that of Enterococcus (1.3 bacteria/cell). According to above results,16 strains were selected to next experiment, the fermentation supernatant of Lactobacillus plantarum had different inhibition effects on some pathogenic microorganism and some lactic acid bacteria of indicator, while the fermentation supernatant of Enterococcus could inhibit all of the pathogenic microorganism of indicator, except that WZ26-1 couldn't inhibit lactic acid bacteria.According to the in vitro screening experiment, Lactobacillus plantarum WZ47-1 was selected to study its regulation function of immunity and intestral microflora of mice. The results showed that the strain could enhance the function of mononuclear macrophage and had no effect on the specific immunity. The strain could modulate the balance of intestral flora.