Probiotic Lactobacillus casei Zhang (LCZ) alleviates respiratory, gastrointestinal & RBC abnormality via immuno-modulatory, anti-inflammatory & anti-oxidative actions

This 12-months randomized, double-blind and placebo-controlled study aimed at investigating the effects of Lactobacillus casei Zhang (LCZ; 9 log CFU daily) against upper respiratory tract infections (URTI) and gastro-intestinal disorders in one hundred thirty-seven (n = 137) healthy adult and elderly Malaysians. LCZ alleviated URTI symptoms in adults, with reduced duration for nasal, pharyngeal, general flu and total respiratory illnesses symptoms compared to the placebo (P < 0.05). These were primarily attributed to activation of T-cells and B-cells and anti-inflammatory properties, as observed via reduced plasma pro-inflammatory cytokines (IL-1), increased anti-inflammatory cytokines (IL-4, IL-10), and upregulated whole blood expressions for CD4, CD8, CD44, CD27 and CXCR5 compared to the placebo (P < 0.05). In elderly subjects, LCZ reduced the duration of nasal symptoms, increased weekly defecation occurrences, and alleviated abnormality of RBC via stabilizing whole blood MCHC and ESR parameters with significant correlations against antioxidative (TBA) and immunomodulatory (CD44) properties, as compared to the placebo (P < 0.05). With increasing needs for more evidence on strain- and host-dependent efficacy, our current study has illustrated the specific potentials of LCZ against URTI and gastrointestinal health in the adult and elderly populations.