Publication:

Comparative assessment of probiotic properties of seven commercially available probiotic strains: an in vitro study

Background Probiotics are live microorganisms that, when administered in adequate amounts, confer health benefits to the host. Their ability to survive harsh gastrointestinal conditions such as low pH, bile salts, and toxic compounds like phenol is crucial for colonization and activity. The present study was undertaken to evaluate the probiotic properties of commercially available probiotic strains including Lactobacillus acidophilus, Limosilactobacillus reuteri, Lacticaseibacillus rhamnosus, Shouchella clausii, Weizmannia coagulans, Bacillus subtilis and Saccharomyces boulardii.

Methods All strains were germinated in brain heart infusion (BHI) broth and subjected to standard probiotic property evaluation. Acid, bile, and phenol tolerance were assessed using modified BHI broth adjusted to pH 2.0, 0.3% bile, and 0.4% phenol, respectively, with viable counts determined at specific time intervals. Antagonistic activity was tested against E. coli isolates by agar overlay method.

Results Among tested strains, Shouchella clausii and Weizmannia coagulans exhibited highest tolerance to acidic, bile and phenolic stress. Limosilactobacillus reuteri showed moderate tolerance, while Lacticaseibacillus rhamnosus and Lactobacillus acidophilus demonstrated fair survival rates. Saccharomyces boulardii and Bacillus subtilis recorded comparatively lower tolerance. Most isolates showed significant inhibitory activity against coliforms.

Conclusions The study highlights the potential of commercially available probiotic formulations as effective candidates for gastrointestinal health. The survival ability of Bacillus species under harsh gut conditions suggests their suitability as stable probiotics. Further studies focusing on molecular mechanisms and clinical efficacy are warranted.