Safety Assessment of Lactobacillus salivarius REN, a Probiotic Strain Isolated from Centenarian Feces

Abstract

The aim of this study was to evaluate the oral safety of Lactobacillus salivarius REN, a probiotic isolated from the fecal samples of a healthy centenarian. BALB/c mice were respectively orally administered with 0, 3 × 10⁸, 5 × 10⁹, or 2 × 10¹⁰ CFU/mouse daily for 28 days, or injected intraperitoneally with 5 × 10⁹ CFU/mouse in a single dose, then killed at day 2 and day 5 after injection, respectively. The results indicated that oral administration of Lactobacillus salivarius REN had no adverse effects on body weight, food intake, hematological and serum biochemical parameters, and there was no treatment-associated bacterial translocation to the blood, liver, spleen, or kidney. Intraperitoneal injection caused bacterial translocation to the liver, spleen, and kidney, except blood, the translocation did not trigger illness or death. This study suggests Lactobacillus salivarius REN is likely to be safe for human consumption.