The Survival Of Probiotic Lactobacillus Casei Zhang In Human Intestinal Tract And The Effect On Intestinal Mirobiota

During the last decade, specific bacterial isolates, termed "probiotics," have been extensively used in an attempt to modulate the intestinal microbiota to benefit the host. Today, there are persuasive evidences for probiotics in prevention or treatment of a number of intestinal disorders in humans. This experiment was generally about the effect of probiotics on human intestinal microbiota at home and abroad, and took Lactobacillus casei Zhang as an example to demonstrate the influence of probiotic on human intestinal tract.The study from the perspective of human gut microflora metagenome, by the methods of16S rDNA, RT-qPCR, DGGE, enzyme immunoassay and high-performance liquid technology, systematically analyzed the residues of that probiotic in intestinal tract and the change of intestinal microflora, short chain fatty acids (SCFAs), total bile acids (TBA) during24volunteers taking L. casei Zhang tablets in three times. The results showed that:(1) On the14th day of taking probiotic, the average number of probiotic in the feces of the24volunteers was8.41±0.68Log10cfu/g, and at day28, L. casei Zhang in the feces of volunteers was at an average of8.55±0.57LoglOcfu/g. Stopping oral taking probiotic at day7, the probiotic in the feces was reduced to5.86±0.59Log10cfu/g, further reduced to5.52±0.57Log10cfu/g to14days, but drop range was not too much. For people of different ages, during taking probiotic period, the feces of this bacteria number in group A (24-26years old)> group C (62-68years old)> group B (34-38years old); and when to stop giving L. casei Zhang, remaining bacteria number in the feces of group C> group B>group A. During and after taking probiotic tablets, the probiotic amount detected in female volunteers’feces was less than the male, but the difference was not significant.(2) The structure of intestinal microbiota changed during the volunteers taking probiotic L. casei Zhang. Taking Lactobacillus group and Bifidobacterium group for example, the number of human body intestinal probiotics significantly increased; and there was a decrease of Bacteroides group, Clostridium group and Prevotella group, except Atopobium cluster increased.(3) Detecting on SCFAs and TBA from feces the result was found that three groups of volunteers, after taking probiotic L. casei Zhang, intestinal acetic acid and propionic acid metabolism level obviously increased, but no significant change on butyrate; the content of TBA from feces of volunteers from Group B and group C significantly reduced, but the influence on volunteers of group A was second. Based on gender group study, the content of SCFA in female feces was slightly higher than male and TBA metabolism level was slightly lower than male. After taking probiotic L. casei Zhang, the diferent influence of SCFAs and TBA from probiotic L. casei Zhang on different gender volunteers was not significant.The results suggested that probiotic L. casei Zhang was able to survive in human intestinal tract, improve intestinal flora composition, enhance SCFA metabolism, suppress secondary bile acid production and have an active and continuous influence on research subjects’ intestinal microbe.