Distribution of bacterial flora in sigmoid colon tissues and stools in normal population

Objective To study the distribution patterns of bacterial flora in sigmoid colon tissues and stools in normal population.Method Bacterial flora were identified and analyzed by using 16sDNA sequencing technology in fresh stool samples (n =13) and colon mucosa samples (n =10).Results The diversity and abundance of bacterial flora were significantly larger in the stool samples than in the sigmoid colon samples (P ＜ 0.001,P ＜ 0.001,P =0.042,P =0.006).The consititution of phylum flora between the two groups were same,including flrmicutes,bacteroides,proteobacteria,and actinomycetes.However,the proportions of firmicutes and bacteroides in stool samples were significantly higher than in the sigmoid colon samples,whereas the proportion of proteobacteria was significantly lower (P ＜ 0.001,P =0.025,P ＜ 0.001).At the genus level,faecalibacterium and bacteroides were the dominant flora in feces,whereas pseudomonas,lactococcus,acinetobacter,and flavobacterium were the most common flora in sigmoid colon mucosa.The amounts of bifidobacterium and lactobacillus were low in both two groups.Conclusion The distribution of bacterial flora remarkably differ in stools and sigmoid colon mucosa. Key words: Normal population;  16s rDNA ;  Sigmoid ;  Feces ;  Flora