Lactococcus lactis Strain Plasma Intake Suppresses the Incidence of Dengue Fever-like Symptoms in Healthy Malaysians: A Randomized, Double-Blind, Placebo-Controlled Trial

Dengue fever (DF) is a mosquito-borne disease still with no effective treatment or vaccine available. A randomized, placebo-controlled, double-blinded, parallel-group trial was undertaken to evaluate the efficacy of oral intake of Lactococcus lactis strain plasma (LC-Plasma) on the presentation and severity of DF-like symptoms among healthy volunteers. Study participants (320) were assigned into two groups, and consumed either placebo or LC-Plasma tablets (approximately 100 billion cells/day) for 8 weeks. The clinical symptoms of DF were self-recorded through questionnaires, and exposure to DENV was determined by serum antibody and/or DENV antigen tests. No significant differences between groups were observed for exposure to DENV, or the symptomatic ratio. Results obtained showed that participants from the LC-Plasma group reported a significant reduction in the cumulative incidence days of DF-like symptoms, which include fever (p < 0.001), muscle pain (p < 0.005), joint pain (p < 0.001), and pain behind the eyes (p < 0.001), compared to that of the placebo group. Subgroup analysis revealed a significantly (p < 0.05) reduced severity score in the LC-Plasma group when study sites were separately analyzed. Overall, our findings suggest that LC-Plasma supplementation reduces the cumulative days with DF-like symptoms, and the severity of the symptoms. Daily oral intake of LC-Plasma, hence, is shown to mitigate the DF-like symptoms.