Immune and metabolic beneficial effects of Beta 1,3-1,6 glucans produced by two novel strains of Aureobasidium pullulans in healthy middle-aged Japanese men: An exploratory study

Abstract

Background: Imbalances in glucose and lipid metabolism in the background of a declining immune system, along with aging, make one prone to glucolipotoxicity-related diseases such as hepatic steatosis and to high risk of infection-related mortality, as with COVID-19, warranting a safe prophylactic measure to help regulate both metabolism and the immune system. Based on the beneficial effects of the AFO-202 strain of black yeast Aureobasidium pullulans-produced beta 1,3-1,6 glucan in balancing of blood glucose and immune enhancement, and that of the N-163 strain of the same species in lipid metabolism and immune modulation, in this pilot study, we have evaluated their specific benefits in healthy human subjects. Methods: Sixteen healthy Japanese male volunteers (aged 40 to 60 years) took part in this clinical trial. They were divided into four groups (n = 4 each): Group I consumed AFO-202 beta glucan (2 sachets of 1 g each per day), IA for 35 days and IB for 21 days; Group II consumed a combination of AFO-202 beta glucan (2 sachets of 1 g each) and N-163 beta glucan (1 sachet of 15 g gel each per day), IIA for 35 days and IIB for 21 days. Investigations for immune stimulation, anti-glycaemic, and anti-cholesterolemia biomarkers were undertaken in all four groups. Results: In terms of metabolic control of glucose, the decrease in HbA1C and glycated albumin (GA) was significantly better in Group I compared with the other groups. Immune enhancement in terms of a significant increase of eosinophils and monocytes and marginal decrease in D-dimer levels, decrease in neutrophil-to-lymphocyte ratio (NLR), with an increase in the lymphocyte-to-CRP ratio (LCR) and leukocyte-to-CRP ratio (LeCR) was observed in Group I. Regulation of lipids by decrease in total and LDL cholesterol was better in Group II, and immunomodulation of coagulation-associated and anti-inflammatory markers by a decrease of CD11b, serum ferritin, galectin-3, fibrinogen was profound in Group II. Conclusion: A. pullulans, a polythermotolerant black yeast - produced AFO-202 beta glucan has balanced blood glucose with marginal immune enhancement in healthy individuals, which when combined with N-163 beta glucan, balanced the lipid profile and immunomodulation. This outcome warrants larger clinical trials to understand the mechanisms and explore the potentials of these safe food supplements in prevention and prophylaxis of diseases due to dysregulated glucose and lipid metabolism, such as fatty liver disease, and infections such as COVID-19 in which a balanced immune activation and immunomodulation are of utmost importance, besides their administration as an adjunct to existing therapeutic approaches of both communicable and non-communicable diseases.