Effects of D-Mannitol and Leucine on Viability and Aerodynamic Performance of Spray-Dried Lactobacillus

Jin-ju Ha – Graduate Student, Chungbuk National University; I-Hyeon Seo – Graduate Student, Chungbuk National University; Dong-Wook Kim – Professor, Wonkwang University; Ji-Hyun Kang – Professor, Jeonbuk National University; Chun-Woong Park – Professor, Chungbuk National University

Introduction:

The lung is recognized as a non-sterile organ with a microbial environment that shapes pulmonary immune regulation. Among lung-associated microbes, Lactobacillus species show beneficial immunomodulatory effects and are widely used as safe probiotics. However, prior work has mainly examined oral or intranasal dosing, and direct pulmonary delivery remains limited. Dry powder inhalers (DPIs) enable localized lung delivery but challenge bacterial viability and aerodynamic performance. This study aimed to develop spray-dried Lactobacillus microparticles optimized for pulmonary delivery.