The Ability of Streptococcus thermophilus BT01 to Modulate Urease Activity in Healthy Subjects' Fecal Samples Depends on the Biomass Production Process

ScopeThis study evaluates how manufacturing conditions of probiotic biomass production, using two different cryoprotectants, Cryo-A and Cryo-B, can affect Streptococcus thermophilus BT01 in vivo gastrointestinal tract survival and its ability to modulate the level of urease activity in fecal samples of healthy subjects. Methods and resultsA randomized controlled cross-over study is carried out on 20 adult healthy subjects to evaluate total and viable loads, persistence of S. thermophilus BT01, and urease activity in fecal samples. Strain-specific quantification by using developed culture-based method and molecular qPCR tool allows to quantify viable S. thermophilus BT01 strain in 90% of the subjects. The quantification of both total DNA and recovered viable S. thermophilus BT01 in fecal samples does not reveal significant differences between Cryo-A or Cryo-B treated biomass. However, the administration of S. thermophilus BT01 produced with Cryo-A results in a decreased urease activity in fecal samples compared to Cryo-B protected cells. ConclusionThis study i) highlights how the manufacturing conditions can play a role in influencing the probiotic functionality in vivo and ii) represents the first evidence that links S. thermophilus to a specific probiotic mechanism, the reduction of urease activity in fecal samples.

Automated summary

This study evaluates the impact of manufacturing conditions on the in vivo functionality of Streptococcus thermophilus BT01 as a probiotic, as well as its ability to modulate urease activity in fecal samples. Results show that the type of cryoprotectant used in the manufacturing process does not significantly affect the viability of S. thermophilus BT01 in fecal samples, but does impact its ability to reduce urease activity. This study highlights the importance of manufacturing conditions in probiotic functionality and provides the first evidence linking S. thermophilus to a specific probiotic mechanism.