A Study On Intestinal Microbiota Of Patients With Colorectal Polyps Among Nonalcoholic Fatty Liver Population

Background and objective:Nonalcoholic fatty liver disease(NAFLD)is considered to be one of the main causes of chronic liver disease worldwide.Some studies have shown that NAFLD increases the risk of colorectal polyps.In recent years,it is generally believed that intestinal microbiota is related to the occurrence and development of many diseases,including NAFLD and colorectal polyps.The purpose of this study is to compare the intestinal microbiota with or without colorectal polyps between NAFLD and non fatty liver population,compare the intestinal microbiota with NAFLD or non fatty liver between polyp and non polyp population,stratified analysis was used to explore the changes of intestinal microbiota structure and abundance,which were significantly related to NAFLD and colorectal polyps,so as to provide scientific basis and research ideas for their risk assessment and clinical treatment.Methods:154 patients were randomly selected from the patients who underwent colonoscopy in Lihuili hospital from December 2018 to December 2019.Before colonoscopy and without taking preoperative preparation drugs,each fresh stool sample was taken for 2g.According to the inclusion and exclusion criteria,the final effective subjects were 65.The 65 subjects were divided into four groups:no NAFLD no colorectal polyps group(NN group),NAFLD with no colorectal polyps group(NF group),colorectal polyps with no fatty liver group(PN group)and NAFLD with colorectal polyps group(PF group).The serum collected from all the subjects were tested for various clinical biochemical indexes,and the feces were sequenced for 16S rDNA high-throughput Illumina sequence and biological analysis.Results:(1)The species diversity of NF group,PN group and PF group were lower than that of NN group.Compared with other three group,the species richness of PF group was the lowest.According to the PCoA analysis chart(Figure 3),the microbial diversity of NN group,NF group,PN group and PF group were significantly different(P<0.05),and there were significant differences between the groups.There are 36 species based on the level of "King,phylum,class,order,family and genus "in NN group and PN group,and the least species based on the level of King,phylum,class,order,family and genus" in NN group and NF group.(2)There was 1 species have higher abundance in NN group than in NF group,it was Klebsiella,with statistical significance(P=0.006).(3)The were 17 species in total have lower abundance in PN group than in NN group,including Archaea,Firmicutes,Euryarchaeota,Clostridia,Methanobacteria,Methanobacteriae,Clostridiales,Methanobactaceae,lachnospiraceae,Mitsuokella,Dorea,Fuscanibacter,Anaerostipes,Methanobrevibacter,Methanosphaera,Blautia,Lachnospiracea_incertae_sedis,with statistical significance(P<0.05).The were 19 species in total have higher abundance in PN group than in NN group,including Bacteroidea,Proteobacteria,Fusobacteria and Candidatus Saccharobacteria,Gamma Proteobacteria,Fusobacteria,Epsilon Proteobacteria,Enter obacteriales,Fsobacteria,Neisseriales,Campylobacter,Enterobacteriaceae,Enterobacteriaceae,with statistical significance(P<0.05).(4)The were 7 species in total have lower abundance in PF group than in NF group,includingCyanobacteria/Chloroplast,Chloroplast,Chloroplast,Clostridialles_insertaeseptisⅩⅢ,Prevotellae,Prevotella and Streptophyta,with statistical significance(P<0.05).The were 3 species in total have higher abundance in PF group than in NF group,including Bacteroideae,Bacteroides and Klebsiella,with statistical significance(P<0.05).(5)The were 10 species in total have lower abundance in PF group than that in PN group including Prevotella,Prevotella,Neisseria,Neisseria,Neisseria,Micrococcaceae,Rothia,dialister,Erysipelotrichaceae_entertae_sedis and Alisonella,with statistical differences Significance(P<0.05).The were 3 species in total have higher abundance in PF group than in PN group,incuding Clostridia,Clostridia and Trichospirillaceae,with statistically significant(P<0.05).Conclusion:(1).The intestinal microbiota structure of patients with NAFLD and no polyps,patients with colorectal polyps and no fatty liver,patients with colorectal polyps and NAFLD had disorder,and the richness and diversity of intestinal microflora decreased compared with the healthy population.Compared with the other three groups,patients with NAFLD and colorectal polyps had the lowest intestinal species richness.(2)There are significant differences in intestinal microbiota diversity between NAFLD and non fatty liver population with or without colorectal polyps,and there are significant differences in intestinal microbiota diversity between polyps and non polyp population with NAFLD or without fatty liver.(3)Some microbial species are beneficial to the host intestinal environment,including Blautia,Cyanobacteria,Bacteroides,Prevotella,etc.(4)Some microbial species are related to the occurrence and development of NAFLD and polyps,including Enterobacteriaceae,Fusobacteria,Proteobacteria,Shigella,Clostridium,Lachnospiraceae,etc.The increased abundance of Shigella may be related to the increased risk of colorectal polyps in patients with NAFLD.