The Effect Of Saccharomyces Boulardii CNCM I-745 On Intestinal Flora And Intestinal Development In Healthy Rats During The Neonatal Period

Objective:To investigate the effects of Saccharomyces boulardii CNCM I-745 on intestinal flora and intestinal development of healthy SD rats in the neonatal stage under the normal colonization mode of intestinal flora.Methods:24 newborn SD rats were randomly divided into experimental group(n=12)and control group(n=12).From postnatal day 2 to PND 6,the experimental group was given to Saccharomyces boulardii CNCM I-745(5×10~6CFU/g·bw,once a day),while the control group was given the equal volume normal saline.At PND7and PND42,six rats were randomly killed in each group,collected the intestinal mucosa and intestinal contents of jejunum and colon for 16s rDNA V4 region second generation sequencing,and the jejunum and colon tissue were retained for pathological examination.Intestinal villus length and crypt depth were measured by Image Pro Plus 6.0,second generation sequencing results were processed and plotted by QIIME and R software;Statistical analysis was carried out by using SPSS 24.0 software package,P=0.05 was considered significant.Results:There was no significant difference in body weight,jejunum and colon inflammation and other pathological changes between the two groups,and no significant difference in jejunum and colon mucosal villi and crypt depth between the two groups(P>0.05).On PND7 and PND42,the Alpha diversity index and Beta diversity of jejunum and colon flora between two groups were no statistically significant difference(P>0.05).On PND7,,there was no statistically significant difference in jejunum and colon flora abundance between the two groups at the phylum level(P>0.05).While at the genus level,compared with the control group,the abundance of Enterococcus in jejunum flora of the experimental group was significantly increased(P<0.01).On PND42,at the phylum level,compared with the control group,the Bacteroidetes in the jejunum flora of the test group increased significantly,Cyanobacteria decreased significantly,and the Vermicularia flora in the colon flora decreased significantly,with statistically significant differences(P<0.05).At the genus level,compared with the control group,the abundance of Allobaculum in jejunum flora in the test group was significantly increased,while the abundance of Rothia,Pasteurella in the experimental group was significantly decreased(P<0.05),and the abundance of Akkermansia,Alloprevotella in the colon flora was significantly decreased(P<0.05).Conclusion:On the basis of the normal colonization mode of intestinal flora,the addition of Saccharomyces boulardii CNCM I-745 in the early stage of life can cause the abundance changes of some intestinal flora,but can’t affect the overall composition of intestinal flora structure,and the obvious health promotion effect can’t be observed.Therefore,in the clinical application of probiotics,the indications and use should be strictly controlled,and off-label use should be minimized to avoid potential adverse outcomes.