A randomized clinical trial enrolling healthy volunteers was carried out to evaluate the effects of S. muticum supplementation. An experiment was conducted to investigate whether intake of S. muticum could exert beneficial effects on human health. Volunteers were asked to consume dried encapsulated S. muticum 4.8 grams daily for 4 weeks. Analysis was made on several parameters including blood lipid profile, stress hormone level, fatigue status, liver functions, and lymphocyte subpopulation level, before and after consumption of the S. muticum capsuls. Fifty-one subjects were able to complete this study. Oxidized LDL (ox-LDL) decreased 14% from the baseline level of 6.0±1.4 μg/mL to 5.1±1.6 μg/mL, and the difference was statistically significant (p<0.05). There was a correlation between decreased ox-LDL levels and increased total antioxidant status (TAS) levels after S. muticum intake. There was a remarkable increase in natural killer (NK) lymphocyte count, but changes in the mean absolute lymphocyte subsets were unremarkable. Healthy subjects showed significant improvement of biomarkers of fatigue and liver functions, such lactate dehydrogenase (LDH), aspartate aminotransferase (AST), and alanine aminotransferase (ALT). These results suggest that S. muticum may have potential beneficial effects as a healthy food supplement through its antioxidant, hepatoprotective and immunologic functions.