Stability and safety study of liquid-suspension bacillus clausii spore probiotics (livespo clausy)

Abstract

Bacillus clausii has been used as probiotic bacteria in dietary supplements because of its prominent probiotic activities including its multi-antibiotic resistance, digestive enzyme production, vitamin synthesis, and immunomodulatory effects. In this study, heat and acid-stability, acute and sub-acute toxicity were conducted to evaluate the stability and safety of liquid-suspension probiotics (LiveSpo® Clausy, LiveSpo Pharma) containing ≥ 2 billion spores/5 mL of Bacillus clausii ANA39 strain. The result showed that the B. clausii ANA39 spores were heat- and acid pH-stable with the remaining survival rate of 60% and 40% at treatment conditions of 80oC and pH 2.0 for 20 min, respectively. Acute toxicity data in mice indicated LD50 was not detectable, even at extremely high dosage of 2.4 x 1010 CFU/kg, indicating LiveSpo® Clausy was in unclassified category. The sub-acute toxicity results showed that the rabbits administrated with B. clausii ANA39 at the dosages of 0.93 mL/kg rabbit/day (equivalent to 0.37 x 109 CFU ANA39 spores/kg rabbit/day) and 2.80 mL/kg rabbit/day (equivalent to 1.12 x 109 CFU of B. clausii ANA39 spores/kg rabbit/day) were healthy and steadily gained weight without any abnormal physiology and anatomy. Thus, LiveSpo® Clausy is resistant to high temperatures and low pH acids, stable for at least 24 months at room temperature, and safe for use as food supplements.