Bionomical Characters Of Anti-HP Lactobacillus Acidophilus And Its Fermented Milk And Their Inhibitory Effects On HP Infection

Part I Study on the bionomical characters and toxicity of anti-HP Lactobacillus acidophilusObjective: To study the bionomical characters of anti-HP Lactobacillus acidophilus, and observe the safety during the acute and long term toxicity in mice and rats.Method: Investigated the growth ability of the anti-HP Lactobacillus acidophilus L4 and L6 in simulated gastric juice and duodenum juice in vitro. Observed the 99Tcm-labed Lactobacillus acidophilus transition in stamache by SPECT for 180min.. 6 doses of L4 and L6 were administrated to mice by oral perfusion, and maximal tolerance dose and tolerant multiple were determines by safety limit test. Maximal dose L4 and L6 were oral perfused to Wistar rats, then observed the pathological changes of rats.Result: When the gastric juice pH descended and culture time lasted , the 2 strains'survival rates decreased. The 2 strains still survived in the juice with pH 1.0 for 2 hours. The 2 selected strains had well survival ability in different bile salt concentiration ranged from 0.03% to 0.48% simulated duodenum juice for 6 h. After perfusion 30 mins, the group's radioactivity of 99Tcm in the rats'stomach began to decrease. The radioactivity of experimental groups was significantly higher than control groups in different time. The result agreed with the result of radioactivity intensity in gastric mucosa. Maximal tolerance dose was 15000mg/ml and tolerant multiple was 429 times. No significant pathological changes were found in rats after L4 and L6 oral perfused in 6 months.Conclusions: The 2 strains could resist the gastric acid and bile salt of simulated gastrointestinal tracts environment, and they could persistence in stomach for long time. L4 and L6 oral perfusion were safe.PartⅡStudy on the inhibitory effects of anti-HP Lactobacillus acidophilus on the adhesion between HP and gastric epithelial cell.Objective: To study the adhesion activity of anti-HP Lactobacillus acidophilus L4 and L6 to gastric epithelial cell, and observe their impact on the adhesion between HPSS1 and gastric epithial cell.Method: Observed the adhesion activity of different concentration Lactobacillus acidophilus L4, L6 and HP strain SS1 to the SGC-7901 on microscope after Gram staining to select the best adhesion concentration. Observed L4 and L6 inhibitory effects on the adhesion between HP SS1 andSGC-7901, and measured the levels of IL-1β, IL-6 and IL-8 in culture supernatant.Result: The different concentration anti-HP Lactobacillus acidophilus L4 and L6 have adhesion activity to SGC-7901. When L4, L6 or HP strain SS1's concentration is 1×109CFU/ml, the adhesion activity is strongest. Adhesion activity of viable organism is stronger than inactivation organism. Adhesion ratio and adhesion index HP SS1 adhesed to SGC-7901 were 86.5% and 45.3, when cocultured with L4 and L6, adhesion ratio significantly decreased to 10.3% and 10.4%, and adhesion index descended to 2.3 and 3.1. At the same time, the levels of IL-1β, IL-6 and IL-8 in the supertanant decreased from 990.03±102.1pg/ml, 595.0±87.1 pg/ml and 1520.8±211.3 pg/ml to 255±102 pg/ml, 73.03±50.6 pg/ml and 522.2±150.6 pg/ml respectively.Conclusions: The study demonstrated that the L4 and L6 have adhesion activity to SGC-7901.They have competitive inhibition on HP strain SS1,and could cut down the level of SGC-7901 secreted inflammatory factor IL-1β,IL-6 and IL-8,which induced by HP strain SS1.They could inhibite both the adhesion between HP SS1 and SGC-7901 and the secretion of IL-1β, IL-6 and IL-8 induced by HP infection.Part IIIStudy on the efficiency stability, preventive and therapeutic effects of the anti-HP Lactobacillus acidophilus fermented milk in C57BL/6 mice with HP infectionObjective: To produce anti-HP Lactobacillus acidophilus L6 fermented milk, observe biological character changes of L6. To study the preventative and therapeutic effects of fermented milk in HP infective C57BL/6 mice.Method: In the 21 days of validity, bacterial counting, strain identification and biological character observation of anti-HP Lactobacillus acidophilus fermented milk were made everyday. Animals were divided into prevention group and treatment group according to anti-HP Lactobacillus acidophilus fermented milk oral perfusion before and after HP strain SS1 inoculation. Observed HP colonization, mononuclear and lymphocytes infiltration and pathological injury of gastric mucosa. Result: Stored at the 4℃condition during 21 days of validity, the survival quantity of L6 had decreasing tendency , but the number of viable probiotics were all more than 106CFU/ml keeping with the efficiency demand of the products. None HP infection were seen in prevention group, and inflammation degree decreased than HP infective group. Mice were all infected with HP in treatment group, but lymphocyte infiltration and HP colonization were milder than HP infected group in 4,8 and 12 weeks observation period. Conclusions: Anti-HP Lactobacillus acidophilus fermented milk could keep the efficiency stability in long time and had preventative and therapeutic effects on the HP infection in C57BL/6 mice.