Prevalence of Anti- Saccharomyces Cerevisiae Antibodies (ASCA) in Patients With Irritable Bowel Syndrome (IBS). A Case-control Study.

Background: Irritable bowel syndrome (IBS) is a disorder of gut-brain interaction that affects patients' quality. Recent research has shown variations in the mycobiome of individuals with IBS, particularly involving Saccharomyces cerevisiae , and its association with dysbiosis and visceral hypersensitivity. However, the role of Anti-Saccharomyces cerevisiae antibodies (ASCA) in IBS remains unclear, despite their significance as markers of disease severity in inflammatory bowel disease.

Objective: This study aimed to investigate the role of ASCA in Mexican IBS patients compared with healthy controls (HCs) and determine whether these antibodies could help differentiate between IBS patients and healthy individuals.

Methods: Serum samples from 400 IBS patients and 400 HC were analyzed. ASCA IgG levels were measured using enzyme-linked immunosorbent assay (ELISA). The IBS patients were further categorized into subtypes: constipation predominant (IBS-C), diarrhea predominant (IBS-D), and mixed (IBS-M).

Results: Among the participants, 66 IBS patients (16.5%) and 63 HC (15.75%) tested positive for ASCA IgG. No significant difference was observed in ASCA IgG levels between the 2 groups ( P value: 0.8451). The prevalence of ASCA IgG positivity was 14.5% in IBS-C, 17.8% in IBS-D, and 15.9% in IBS-M.

Conclusion: Surprisingly, a high prevalence of ASCA IgG was found in the HC group in Mexico. Furthermore, there was no significant difference in ASCA IgG levels between IBS patients and controls. These findings suggest that ASCA is not useful as a discriminatory biomarker for distinguishing IBS patients from healthy individuals and cannot serve as a surrogate marker for visceral hypersensitivity.