Randomized Clinical Trial for the Evaluation of Immune Modulation by Yogurt Enriched with β-Glucans from Lingzhi or Reishi Medicinal Mushroom, Ganoderma lucidum (Agaricomycetes), in Children from Medellin, Colombia.

Pattern recognition receptor (PRR) agonists are promising for use in modulating immune responses in clinical settings characterized by immune immaturity or deficiency. β-Glucans derived from Ganoderma lucidum have demonstrated immune-modulatory activity both in vitro and in vivo. To evaluate the immunomodulatory activity of orally administered β-glucans, a randomized, double-blinded, placebo-controlled clinical study was performed in asymptomatic children, aged 3 to 5 years old, from Medellin, Colombia. Primary outcomes were the circulating CD8+ T lymphocyte and natural killer cell counts; secondary outcomes were circulating lymphocyte counts (total, CD3+, and CD4+ T cells), serum concentrations of total immunoglobulin A and cytokines, and various hematological parameters. The treatments were administered daily for 12 weeks, and physical and laboratory evaluations were performed at days 0 and 84. Children in the group receiving a yogurt with β-glucans presented a significantly higher absolute count of peripheral blood total lymphocytes (CD3+, CD4+, and CD8+ T cells) than that in the group receiving placebo. The interventions were safe and well tolerated; no abnormal increases in serum creatinine or hepatic aminotransferases occurred, and adherence was higher than 90% in the intervention groups. This study demonstrates that β-glucans from G. lucidum increase the frequency of immune system cells in the peripheral blood; these cells are critical in the defense against infectious threats in asymptomatic children 3 to 5 years old. These findings warrant longer controlled clinical trials that aim to evaluate the efficacy of β-glucans in preventing infections in healthy children and to define their potential to enhance lymphoid cell number and functions in various lymphoid immune deficiencies.