Dysbiosis of gut microbiota in Polish patients with ulcerative colitis: a pilot study

Oliwia Zakerska-Banaszak,Natalia Malinska,Michal Michalak,Ryszard Slomski,Piotr Eder,Agnieszka Dobrowolska,Hanna Tomczak,Dorota Mankowska-Wierzbicka,Marcin Gabryel,Marzena Skrzypczak-Zielinska,Alina Baturo,Lukasz Wolko

doi:10.1038/s41598-021-81628-3

Abstract

Ulcerative colitis (UC) is a chronic immune-mediated disorder, whose etiology is not fully understood and for which no effective treatment is available. Recently, research has focused on the dysbiosis of gut microbiome in UC. However, the results so far remain inconsistent and insufficient to understand the microbial component in UC pathogenesis. In this study, we determine specific changes in the gut microbial profile in Polish UC patients compared to healthy subjects for the first time. Using 16S rRNA gene-based analysis we have described the intestinal microbial community in a group of 20 individuals (10 UC patients and 10 controls). Our results after multiple hypothesis testing correction demonstrated substantially lower gut microbiome diversity in UC cases compared to the controls and considerable differences at the phylum level, as well as among 13 bacterial families and 20 bacterial genera (p < 0.05). UC samples were more abundant in Proteobacteria (8.42%), Actinobacteria (6.89%) and Candidate Division TM7 (2.88%) than those of healthy volunteers (2.57%, 2.29% and 0.012%, respectively). On the other hand, Bacteroidetes and Verrucomicrobia were presented at a lower level in UC relative to the controls (14% and 0% vs 27.97% and 4.47%, respectively). In conclusion, our results show a reduced gut microbial diversity in Polish UC patients, a reduction of taxa with an anti-inflammatory impact and an increased abundance of potentially pathogenic bacteria.

Highlights

Ulcerative colitis (UC) is a chronic immune-mediated disorder, whose etiology is not fully understood and for which no effective treatment is available
Current research reports changes in gut microbiota balance in UC patients, underlying the possible role of microbial flora in UC pathogenesis. It still remains unclear whether dysbiosis is a cause or consequence of intestinal inflammation, much research has shown that gut microbiota constitute a crucial element of the host immune system, gut-associated lymphoid tissue (GALT), and disturbances to it may affect various d iseases[14,15]
The current study aimed to indicate the specific changes in the gut microbiota for Polish patients with UC compared to healthy volunteers

Summary

Introduction

Ulcerative colitis (UC) is a chronic immune-mediated disorder, whose etiology is not fully understood and for which no effective treatment is available. Current research reports changes in gut microbiota balance in UC patients, underlying the possible role of microbial flora in UC pathogenesis. It still remains unclear whether dysbiosis is a cause or consequence of intestinal inflammation, much research has shown that gut microbiota constitute a crucial element of the host immune system, gut-associated lymphoid tissue (GALT), and disturbances to it may affect various d iseases[14,15]. Human gut microbiota is composed of around 400–500 bacterial species, of which over 90% belong to four major phyla, i.e. Firmicutes, Bacteroidetes, Proteobacteria and Actinobacteria[21,22,23].

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