Differences in the Intestinal Flora of Patients with Inflammatory Bowel Disease in Southwest China

Microbial Disruptions in Inflammatory Bowel Disease: A Comparative Analysis

Objective

The fecal microbiota was studied in patients with inflammatory bowel disease (IBD), and the characteristics of gut microbiota were compared among patients with different subtypes and stages of IBD, aiming to identify the gut microbiota associated with IBD.

Methods

Fecal samples were collected from 41 IBD patients (18 patients with ulcerative colitis [UC] and 23 patients with Crohn's disease [CD]) in the Department of Gastroenterology of East China Hospital, Fudan University between January 2021 and January 2022. In addition, fecal samples were collected from 20 healthy volunteers. The fecal microbiota was subjected to 16S rRNA gene sequencing, followed by bioinformatics analysis.

Results

There was significant difference in the fecal microbiota between IBD patients and controls. The abundance and diversity of fecal microbiota in the IBD patients were significantly lower than in controls. The relative abundance of Subdoligranulum, Ruminococcus, Anaerostipes and Lachnospira was reduced markedly in the IBD patients. As compared to controls, the relative abundance of Streptococcus increased dramatically in the UC patients. The relative abundance of Lachnoclostridium, Fusobacterium, Cloacibacillus and Erysipelatoclostridium significantly increased in the CD patients. As compared to CD patients, the relative abundance of Alistipes was reduced markedly in the UC patients; the relative abundance of Faecalibacterium, Roseburia and Haemophilus was reduced dramatically in the CD patients. In addition, significant difference was also noted in the fecal microflora between patients with active IBD and those with IBD in remission period. In active IBD patients, the relative abundance of Roseburia, Coprococcus and Ruminiclostridium was reduced significantly.

Conclusion

There is intestinal microbiota imbalance in IBD patients, and the abundance of Roseburia, Coprococcus and Ruminiclostridium is reduced significantly in the active period of IBD, which may be related to the active IBD.

Porcine-derived antimicrobial peptide PR39 alleviates DSS-induced colitis via the NF-κB/MAPK pathway

PR39 is an antimicrobial peptide (AMP) with a variety of biological functions, including antimicrobial, wound healing, leukocyte chemotaxis, angiogenesis, and immunomodulation; however, its therapeutic efficacy in colitis (IBD) has rarely been reported. For this reason, the present study aimed to investigate the therapeutic effect of PR39 on IBD and its underlying mechanisms. In this experiment, a mouse model of ulcerative colitis (UC) was induced with 3 % dextran sulfate (DSS) and administered by rectal injection of PR39. The results of the study showed that 5 mg/kg of PR39 was able to ameliorate the clinical manifestations of DSS-induced UC mice by improving the clinical symptoms, colonic tissue damage, up-regulating the expression of tight junction proteins, and alleviating the systemic inflammation in mice in various ways. The mechanism of action may involve inhibition of the phosphorylation level of proteins related to the NF-κB/MAPK signaling pathway and modulation of the relative abundance of potentially pathogenic (Bacteroides, Pseudoflavonifractor, Barnesiella, and Oscillibacter) and potentially beneficial bacteria (Candidatus_Saccharibacteria, Desulfovibrio, Saccharibacteria) in the intestinal flora. The results enriched the biological functions of PR-39 and also suggested that PR-39 may be able to be used as a novel drug for the treatment of IBD.