Evaluation of Gut Microbiota Variations and its Relationship with Interleukin-6 and β-Defensin-2 in Patients with Irritable Bowel Syndrome

Mohammed, Alaa E.; Agban, Michael N.; Ali, Mohamed S.B; Kamel, Sherif I.; Elkhawaga, Amal A.

doi:10.21608/ejmm.2025.379623.1597

Evaluation of Gut Microbiota Variations and its Relationship with Interleukin-6 and β-Defensin-2 in Patients with Irritable Bowel Syndrome

Document Type : New and original researches in the field of Microbiology.

Authors

¹ General Directorate of Medical Affairs, Assiut University, Egypt

² Department of Medical Microbiology & Immunology, Faculty of Medicine Assiut University, Egypt

³ Department of Tropical Medicine, Faculty of Medicine Assiut University, Egypt

10.21608/ejmm.2025.379623.1597

Abstract

Background: Irritable bowel syndrome (IBS) is a common gastrointestinal condition involving disruptions in gut microbial communities and immune system imbalances. Although previous research has examined microbial alterations in IBS, the connection between beneficial bacterial populations and immune indicators remains unclear. Objectives: This study aimed to explore changes in Bifidobacterium and Lactobacillus levels in IBS patients and their relationship with interleukin-6 (IL-6) and human β-defensin-2 (HBD-2). Methodology: A total of 55 individuals diagnosed with IBS (subcategorized into IBS-C, IBS-D, and IBS-M) and 26 healthy individuals participated in the study. Stool and blood samples were obtained. Quantitative real-time PCR was used to assess Bifidobacterium and Lactobacillus levels. ELISA was performed to measure serum IL-6 and fecal HBD-2 concentrations. Statistical analyses were conducted to compare groups and evaluate correlations between microbial and immune variables. Results: IBS patients exhibited a marked reduction in the levels of Bifidobacterium and Lactobacillus compared to healthy controls. Additionally, serum IL-6 and fecal HBD-2 concentrations were significantly elevated in the IBS group. A significant positive correlation was found between IL-6 and HBD-2 levels among IBS patients, while other correlations were not statistically significant. No meaningful differences in microbial or immune profiles were detected between IBS subtypes. Conclusion: The results suggest that gut microbial imbalance and immune activation, particularly increased IL-6 and HBD-2, may contribute to IBS pathogenesis. The observed link between IL-6 and HBD-2 supports a possible interaction between immune responses and antimicrobial peptide production, offering insight into potential microbiota-targeted therapies for IBS.

Keywords