Isolation And Screening Of Probiotics:Their Role And Mechanisms In The Treatment And Prevention Of Acute Liver Injury

The gut hosts up to100trillion (1014) microbes from1,000different species which have important role on human body. Lots of studies proved that gut microbiota has close relationship with liver diseases. The effects of probiotics in the treatment of liver diseases are very important.The objective of this research is to screening and study on probiotics which have independent intellectual property rights and can be used to prevent and treat in liver diseases. In this study, we screening and identificated five lactic acid bacteria after morphological observation, MALDI-TOF-MS identification,16S rDNA sequencing, resistance to acid and bile salt, antibacterial test. Then we investigated the effect of intragastric administration of five lactic acid bacteria from healthy people on acute liver failure. Sprague-Dawley rats were given intragastric supplements of Lac-15, Lac-16, Lac-5, Lac-10or Ped-1for8days. Acute liver injury was induced on the eighth days by intraperitoneal injection of1.1g/kg D-galactosamine. Rats were sacrificed after24hours. Samples were collected to determine liver enzymes, liver functions, histology of the terminal ileum and the liver, the serum levels of inflammatory cytokines, bacterial translocation, and the composition of gut microbiome. Results show Lac-10, Lac-15, Ped-1, or Lac-16reduced elevated aspartate transaminase; Lac-15or Ped-1reduced elevated alanine transaminase. Lac-15or P Ped-1prevented increase of the total bilirubin, but significantly increased the serum level of IL-10.Lac-10or Ped-1increased INFγ. All·strains except Lac-5reduced the histological abnormalities of D-GalN-induced liver injury; but only Lac-15or Ped-1reduced histological abnormalities of the terminal ileum. Lac-15, Lac-5or Ped-1show good ability in preventing bacterial translocation. The cecal microbiome composition in the group supplemented with either Lac-15or Ped-1was clearly apart from that in the liver injury by PCR-DGGE analysis. The excellent characters of Lac-15and Ped-1enable them to be potential probiotics in preventing or treating acute liver failure.We sequenced the whole genome of Ped-1and Lac-15, and determined the ability to reduce acute liver injury.The resluts of Ped-1and Lac-15isolated from the human gastrointestinal tract allow for facilitating the future development of drugs for liver diseases.