Generally, intestinal microbiota can be classified into intestinal cavity microbiota and mucosal microbiota, among which, the former is the default type. This study aimed to identify the differences between fecal microbiota and intestinal fluid microbiota in colon polys. This study enrolled patients with colon polys who met the Rome-III criteria to carry out 16s rDNA gene sequencing. Then, both fresh feces as well as intestinal fluid was sampled. Thereafter, α/β diversities, together with the heterogeneities with regard to microbial function and structure were assessed among those intestinal fluid and fresh feces samples collected. According to bioinformatics analysis, difference in α-diversity was not statistically significant between intestinal fluid microbiota and fecal microbiota among patients with colorectal polyps (CPs). Non-metric multidimensional scaling analysis of β-diversity revealed that differences were of statistical significance between both groups. In addition, linear discriminant analysis effect size analysis displayed great heterogeneities in intestinal microbiota of both groups, including Firmicutes, Clostridia, and Phascolarctobacterium. At the phylum level, difference ( P = .016) in Spirochaetes was statistically significant between the intestinal fluid group and fecal group. At the family level, differences in Bacteroidaceae, Micrococcaceae, F16, Spirocheatacae, Enterobacteriaceae, Cardiobacteriaceae, Turkish Spirobacteriaceae, Bifidobacteriaceae, and Dethiosulfovibrionaceae were statistically significant between the 2 groups. At the genus level, there were statistical differences between the 2 groups in terms of Bacteroidetes, Rothia, Actinobacillus, F16, Treponema, Oscillospira, Turicibacter, Sharpea, Heamophilus, Veillonella, and Cardiobacterium. There are statistical differences in the composition between intestinal microbiota and fecal microbiota in CP patients, both of which are equally important and indispensable for analyzing the intestinal microbiota in CP patients.

Background MicroRNAs are a class of small non-coding RNAs which act as oncogenes or tumor suppressors through targeting specific mRNAs. MiR-3622a-3p is found to be decreased in colorectal cancer (CRC) in TCGA database and there are few reports about the role of miR-3622a-3p in cancers. Our research aimed to explore the effect of miR-3622a-3p in CRC. Methods MiR-3622a-3p expression in CRC tissues and cells was examined by qRT-PCR. The effect of miR-3622a-3p on proliferation, apoptosis, cell cycle, migration and invasion of CRC cells were investigated by a serious of biological function assays. We performed dual luciferase assay to confirm the interaction between miR-3622a-3p and its potential target gene. Western blot was carried out to determine the effect of miR-3622a-3p on stemness features and EMT. Tumor xenograft model and in vivo metastasis model were established using nude mice. The CRC organoid model was constructed with fresh CRC tissues. Results MiR-3622a-3p was down-regulated in CRC tissues and cells. Biological function assays revealed that miR-3622a-3p could inhibit the malignant biological properties of CRC. MiR-3622a-3p suppressed stemness features and EMT of CRC cells by SALL4 mRNA degradation. The results of animal experiments showed miR-3622a-3p could inhibit CRC cell proliferation and metastasis in vivo . The growth of organoids was also suppressed by miR-3622a-3p. Conclusions Taken together, the results of our study indicate miR-3622a-3p exerts antioncogenic role in CRC by downregulation of SALL4. The research on miR-3622a-3p might provide a new insight into treatment of CRC.