AUTHOR=Ni Weiwei , Jiao Xinwei , Zou Huihuang , Jing Mengjuan , Xia Ming , Zhu Shichao , Li Liming 

TITLE=Gut microbiome alterations in ICU patients with enteral nutrition-related diarrhea

JOURNAL=Frontiers in Microbiology

VOLUME=Volume 13 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2022.1051687

DOI=10.3389/fmicb.2022.1051687

ISSN=1664-302X

ABSTRACT=Enteral nutrition-related diarrhea (END) is an extremely common complication in intensive care unit (ICU) patients. However, it is currently unclear whether the patient's gut microbiota is disturbed. Our study aimed to explore the characteristics of gut microbiota changes in END patients. We divided ICU patients into no-END group (n=7) and END group (n=7) according to whether they had END, then stool bacterial DNA was collected separately, and the V3-V4 region of 16S rRNA was amplified using the Illumina MiSeq PE300 sequencing platform.  Microbiome data obtained by quality control were analyzed, including bacterial richness (Ace and Chao indices) and diversity (Shannon and Simpson indices) in alpha-diversity as well as differences in microbiota composition in beta-diversity. Additionally, PICRUSt was used to align species composition information with the KEGG database to predict functional gene composition, thereby analyzing the impact of END on intestinal function.The results showed that the dominant gut microbiota in ICU patients who were given total enteral nutrition were Firmicutes (65.68%), Proteobacteria (16.13%), Bacteroidetes (9.49%), Actinobacteria (4.99%), and Verrucomicrobia (3.55%). Bacterial richness and diversity in END patients were all significantly lower than those in no-END patients (P<0.05). In addition, END caused significant changes in bacterial composition. LEfSe (LDA>4.0) found 34 biomarkers represented by Bacteroidetes and Subdoligranulum in the no-END group as well as 11 biomarkers represented by Enterococcus and Klebsiella in the END group. Finally, through PICRUST function prediction, we found that diarrhea led to abnormal changes in numerous KEGG pathways mainly related to immunity and metabolism. Our findings suggest that ICU patients with END have severe gut dysbiosis, which may have negative consequences for normal gut function.