P053 Overabundance of Lactobacillus species in gut microbiota of IBD patients

Abstract

Abstract Background Changes in the composition of gut microbiota, and their metabolic pathways, are important factors in the pathogenesis of inflammatory bowel disease (IBD). Many clinical trials have shown that taking probiotics based on Lactobacillus has a positive effect on patients with IBD. However, Lactobacillus should be used more carefully during the active phase of IBD, since some strains can negatively affect the pathogenesis of the disease1,2. The aim of this study was to assess the diversity of Lactobacillus species in the gut microbiome of IBD patients and healthy volunteers. Methods In the study, 62 stool samples from healthy people, 31 from patients with Crohn’s disease (CD), and 34 - ulcerative colitis (UC) in active phase were analyzed. DNA was isolated using the QIAamp Fast DNA Stool Mini Kit (Qiagen, USA) following with shotgun metagenomic sequencing the NextSeq 500 (project #0671-2020-0058). Bioinformatic analysis was performed with the MetaPhlAn2 package. Results An increased relative abundance of Lactobacillus was found in patients with IBD (3.2% ± 6.6% in CD and 1.6% ± 2.8 in UC) compared to healthy individuals (0.3% ± 1.2%, p<0.05). In the control group, Lactobacillus were absent in 41% of samples and 1–5 species were found in 58% of samples. Most CD and UC patients are characterized by the presence of 3 to 5 species of Lactobacillus (38% and 31%, respectively). For 23% of CD patients and 26% of UC patients, 6 to 9 types of Lactobacillus were found. Some patients with IBD have more than 10 different types of Lactobacillus in the gut microbiota (Fig.1). The intestinal microbiota in IBD patients is characterized by an increased abundance of several species: L. salivarius, L. gasseri, L. mucosae, as well as L. casei paracasei in patients with CD and L. vaginalis in patients with UC (Fig.2). Conclusion The composition of the intestinal microbiota of IBD patients differs significantly in terms of Lactobacillus proportion and species diversity. Overabundance of five Lactobacillus species could be associated with the active phase of IBD. References