Processing of potential upper respiratory tract probiotics by spray drying

To shorten the duration of upper respiratory tract (URT) diseases or reduce the symptoms alternative treatments to antibiotics and decongestants are needed, due to their side effects and frequent failure. Recent human microbiome research has led to the hypothesis that beneficial bacteria, capable of colonizing the human URT, could constitute an interesting approach to prevent and reduce URT diseases. Since probiotics are live microorganisms with a beneficial effect on the host, it is important that the probiotic bacteria are delivered at the site of action, without hampering their viability. Here, the formulation applicability of eight new probiotic candidates belonging to the Lactobacillus genus was evaluated after spray drying. Besides viability, growth and fermentation abilities after drying were confirmed through experiments. A promising strain was chosen for further optimization. Microscopic visualization and flow cytometry of bacterial morphology identified spray drying as a suitable processing method. Adhesion experiments indicated no changes in functionality. Lastly, the contact time between bacteria and hot drying air was identified as a crucial parameter in spray drying of probiotics.

Automated summary

This study evaluated the formulation applicability of eight new probiotic candidates belonging to the Lactobacillus genus after spray drying. A promising strain was chosen for further optimization based on viability, growth, and fermentation abilities post-drying. Microscopic visualization and flow cytometry confirmed spray drying as a suitable processing method, and adhesion experiments indicated no changes in functionality. The contact time between bacteria and hot drying air was identified as a crucial parameter in spray drying of probiotics.