Lacticaseibacillus rhamnosus Infective Endocarditis Complicated by Multifocal Mycotic Aneurysms in an Immunocompetent Patient: A Case Report.

Lactobacillaceae are generally considered low-pathogenicity organisms but can occasionally cause severe infections. We report a severe case of infective endocarditis caused by Lacticaseibacillus rhamnosus complicated by multifocal mycotic aneurysms in an immunocompetent patient who consumed probiotic drinks daily. He had a history of hypertension and aortic valve regurgitation.After starting antimicrobial treatment, the patient had rapid disease progression and required emergency surgery to prevent the rupture of two abdominal aneurysms. He subsequently experienced a rupture of an intracranial aneurysm, leading to a subarachnoid and intraventricular hemorrhage. This case highlights the potential severity of Lactobacillaceae infections, even in immunocompetent individuals with daily probiotic consumption. Interest in the health benefits of probiotics has grown in recent years, leading to increased global demand. The number of reported cases of Lactobacillaceae infections has also increased. When using probiotics, both the potential benefits and risks need to be considered, especially in susceptible individuals with predisposing conditions.