Introduction:

The gastrointestinal microbiota is thought to play a role in the pathogenesis of food allergies. One potential contributing factor is small intestinal bacterial overgrowth (SIBO).

Aim:

This study aims to investigate the prevalence of small intestinal bacterial overgrowth (SIBO) in patients with diagnosed allergic diseases and to assess potential associations between SIBO and allergy burden.

Material and methods:

This study included 44 patients aged 21–73 years, who were evaluated for suspected food hypersensitivity of various origin. A medical history was collected, followed by a physical examination, point-of-care skin tests and a breath test for SIBO. Patients with celiac disease, known autoimmune or malignant disorders, or those receiving medications that could influence study outcomes were excluded. Additionally, patients who had recently undergone endoscopy or abdominal surgery, were experiencing an exacerbation of a chronic illness, or had an acute infection were not included in the study.

Results:

A positive breath test for SIBO was found in 85.7% of patients with a history of food allergy and 78.3% of patients without confirmed allergy; however, the difference was not statistically significant.

Conclusions:

This pilot study did not confirm a higher prevalence of SIBO in patients with food allergies compared to those without. Further studies with larger sample sizes and more comprehensive allergological diagnostics are needed to definitively assess the potential link between SIBO and food allergies.