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Fecal Proteolytic Bacteria and Staphylococcal Superantigens Are Associated With Abdominal Pain Severity in Irritable
Runze Quan1, Lisse Decraecker1, Iris Appeltans1
1Center for Intestinal Neuroimmune Interactions, Translational Research Center for Gastrointestinal Disorders (TARGID), KU Leuven Department of Chronic Diseases and Metabolism (CHROMETA), KU Leuven, Leuven, Belgium.
Introduction:
Changes in the composition of the gut microbiota have been associated with the development of irritable bowel syndrome (IBS). However, to what extent specific bacterial species relate to clinical symptoms remains poorly characterized. We investigated the clinical relevance of bacterial species linked with increased proteolytic activity, histamine production, and superantigen (SAg) production in patients with IBS.
Methods:
Fecal (n = 309) and nasal (n = 214) samples were collected from patients with IBS and healthy volunteers (HV). Clinical symptoms and gut transit time were evaluated. Bacterial abundance in feces and nasal swabs as well as fecal trypsin-like activity were assessed.
Results:
The percentage of fecal samples containing Staphylococcus aureus was significantly higher in IBS compared with HV. Forty-nine percent of S. aureus -positive fecal samples from patients with IBS were also positive for SAgs, compared with 12% of HV. Patients with IBS and positive fecal SAg-producing S. aureus reported higher pain scores than those without S. aureus . Moreover, increased fecal proteolytic activity was associated with abdominal pain. Fecal abundance of Paraprevotella clara and Alistipes putredinis was significantly decreased in IBS, particularly in samples with higher proteolytic activity. Patients with lower Alistipes putredinis or Faecalibacterium prausnitzii abundance reported more severe abdominal pain.
Discussion:
In keeping with our preclinical findings, we show that increased presence of SAg-producing S. aureus in fecal samples of patients with IBS is associated with increased levels of abdominal pain. We also show that increased fecal proteolytic activity is associated with increased abdominal pain in patients with IBS.
Insights
The gut bacterium Staphylococcus aureus, particularly strains producing superantigens (SAgs), is linked to increased abdominal pain in irritable bowel syndrome (IBS) patients. Reduced levels of certain gut bacteria and increased proteolytic activity also correlate with IBS pain.
Area of Science:
- Microbiology
- Gastroenterology
- Human Health
Background:
- Gut microbiota alterations are implicated in Irritable Bowel Syndrome (IBS).
- The specific roles of bacterial species in IBS symptoms are not well understood.
- This study examines bacteria associated with proteolytic activity, histamine, and superantigen (SAg) production in IBS.
Purpose of the Study:
- To investigate the clinical relevance of specific bacterial species in IBS patients.
- To determine the association between bacterial products (proteolytic activity, SAgs) and IBS symptoms.
- To explore the relationship between gut bacteria and abdominal pain in IBS.
Main Methods:
- Collected fecal and nasal samples from IBS patients (n=309) and healthy volunteers (HV, n=214).
- Assessed clinical symptoms, gut transit time, bacterial abundance, and fecal proteolytic activity.
- Quantified Staphylococcus aureus and superantigen (SAg) presence in fecal samples.
Main Results:
- Staphylococcus aureus was more prevalent in IBS fecal samples.
- SAg-producing S. aureus was significantly higher in IBS patients (49%) compared to HV (12%).
- Increased fecal proteolytic activity and lower abundance of Alistipes putredinis and Faecalibacterium prausnitzii correlated with higher abdominal pain scores in IBS.
Conclusions:
- Increased SAg-producing S. aureus in IBS is linked to heightened abdominal pain.
- Elevated fecal proteolytic activity is associated with increased abdominal pain in IBS patients.
- Specific gut bacterial profiles may contribute to IBS symptom severity.
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