Mitral Regurgitation and Small Intestinal Bacterial Overgrowth in Dogs: A Co-morbidity or Consequle of ‘Gut-Heart Axis

Year 2025, Volume: 19 Issue: 57, 48 - 55, 01.12.2025

Kerem Ural , Hasan Erdoğan , Serdar Paşa , Songül Erdoğan , Tahir Özalp

https://doi.org/10.5281/zenodo.17569130

Abstract

Small intestinal bacterial overgrowth (SIBO) is a clinical condition characterised by the presence of colon-derived bacteria in the small intestine at a density of ≥10⁵ CFU/mL. Congestive heart failure (CHF) causes structural and functional changes in the gastrointestinal tract and has been associated with increased bacterial colonisation, inflammation and malabsorption. A total of 7 dogs with different stages of mitral valve disease and congestive heart failure were included in the study. All dogs were evaluated by clinical examination, laboratory tests involving relevant cardiopulmonary biomarkers and echocardiography. Lactulose-based breath test (LBT) test was used for SIBO and 16S rRNA gene sequencing was used for intestinal microbiota analysis. In the result, Peptoclostridium sp. was identified as the most frequently detected species in the fecal microbiota of dogs with congestive heart failure due to mitral regurgitation. In all cases, an increase of ≥20 ppm compared to the baseline value was observed in the LBT, which was evaluated in favor of SIBO. The most significant increase in hydrogen levels was noted at 60 and 90 minutes. In conclusion, CHF is closely associated with gut microbiota and intestinal dysbiosis should be evaluated in cases of heart disease.

Keywords

Small intestinal bacterial overgrowth , Chronic heart failure , Myxoid mitral valve disease , Dysbiosis

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