Lactobacillus Bacteremia and Probiotics: A Review

Abstract

Lactobacilli are widely found in nature, are commensal microbes in humans, and are commonly used as probiotics. Concerns about probiotic safety have arisen due to reports of bacteremia and other <i>Lactobacillus</i>-associated infections. We reviewed the literature for articles on the pathogenicity of <i>Lactobacillus</i> spp. bacteremia and reports of probiotics in these patients. Our aim is to review these articles and update the present knowledge on the epidemiology of <i>Lactobacillus</i> spp. bacteremia and determine the role of probiotics in <i>Lactobacillus</i> bacteremia. <i>Lactobacillus</i> bacteremia is infrequent but has a higher risk of mortality and risk factors, including severe underlying diseases, immune system suppression, admission to intensive care units, and use of central venous catheters. A variety of <i>Lactobacillus</i> species may cause bacteremia and may or may not be associated with probiotic exposure. To determine if oral probiotics are the source of these infections, the blood isolates and the oral probiotic strain(s) must be compared by sensitive identification methods. The prevalence of <i>Lactobacillus</i> bacteremia is infrequent but is more common in patients taking probiotics compared to those not taking probiotics. Three probiotics (<i>Lacticaseibacillus rhamnosus</i> GG, <i>Lactiplantibacillus plantarum</i>, and <i>Lacticaseibacillus paracasei</i>) were directly linked with blood isolates from bacteremia patients using molecular identification assays.