Beneficial Immune Regulation by Biological Response Modifier Glucans in COVID-19 and Their Envisaged Potentials in the Management of Sepsis

Fungal β-Glucans: Biological Properties, Immunomodulatory Effects, Diagnostic and Therapeutic Applications

Research from the past to the present has shown that natural ingredients in the human daily diet play a crucial role in preventing various diseases. One well-known compound is β-glucan, a natural polysaccharide found in the cell walls of many fungi, yeasts, and some microorganisms, as well as in plants such as barley and wheat. β-glucans are widely recognized for their ability to lower cholesterol and blood glucose levels, thereby reducing the risk of cardiovascular disease and diabetes. In addition to their effects on lipid levels and glucose metabolism, these molecules exhibit antioxidant properties by eliminating reactive oxygen species. As a result, they help lower the risk of conditions such as atherosclerosis, cardiovascular disease, neurological disorders, diabetes, and cancer. Furthermore, β-glucans have been reported to possess immune-boosting and antitumor effects. By binding to specific receptors on the surface of immune cells, they stimulate immune activity. Additionally, β-glucans belong to a group of probiotics that promote the growth and activity of beneficial gut microbiota, preventing the proliferation of harmful pathogens. They play a vital role in maintaining gastrointestinal health, reducing inflammation, and lowering the risk of colon cancer. Further research on the health benefits of β-glucans may be key to improving overall well-being and preventing many chronic non-communicable diseases such as diabetes, high cholesterol, obesity, cardiovascular disease, and cancer.

The Role of Dectin-1-Akt-RNF146 Pathway in β-Glucan Induced Immune Trained State of Monocyte in Sepsis

Background

Sepsis is regarded as a dysregulated immune response to infections. Recent study showed partially reversal of immunosuppression by trained immunity, which fosters an enhanced immune response towards a secondary challenge. However, the role of trained immunity in sepsis has not been fully understood.

Methods

We profiled the characteristics of peripheral blood mononuclear cells from septic patients using single-cell RNA sequencing (scRNA-seq) analyses. Murine double-hit models (pretreatment or post-treatment of β-glucan in septic mice) and murine monocyte/macrophage cell line RAW264.7 were used then.

Results

scRNA-seq revealed that Ring finger protein 146 (RNF146) and protein kinase B (Akt) were downregulated in the immunosuppression period of septic patients and were verified to be decreased in bone marrow and spleen monocytes from septic mice. While β-glucan pretreatment improved the immunosuppressed state in septic mice and increased dectin-1/Akt/RNF146 expressions in monocytes, along with the increased survival rate, inflammatory factors and aerobic glycolysis, indicating a change from immunosuppression to immune training. Moreover, RNF146 regulated dectin-1-Akt-mTOR signaling in the trained immune state of murine monocyte/macrophage RAW264.7 cell line and the expression of RNF146 was dependent on dectin-1-Akt activation. The inhibition of dectin-1 by its antagonist laminarin downregulated Akt-RNF146 signaling and partially reversed β-glucan induced trained immunity in septic mice.

Conclusion

RNF146 and Akt are downregulated in the immunosuppression period of sepsis, while increased after β-glucan pretreatment induced trained immunity in septic mice. Moreover, RNF146 regulates the immune trained state of monocyte through dectin-1-Akt-mTOR pathway, suggesting a possible target in reversal of immunosuppression in sepsis.

Efficient Control of IL-6, CRP and Ferritin in COVID-19 Patients With Two Variants of Beta-1,3-1,6 Glucans in Combination: An Open-Label, Prospective, Randomised Clinical Trial

Background

Several biomarkers, including C-reactive protein (CRP), ferritin, D-dimer, and Interleukin-6 (IL-6), are established predictors of disease severity and respiratory failure in patients with COVID-19.

Objective

In this randomised clinical study, we evaluated the efficiency of the combination of 2 variants' AFO-202 and N-163 strains of Aureobasidium pullulans produced 1,3-1,6 β-glucans in comparison with the control arm on these biomarkers in COVID-19 patients.

Methods

Forty RT-PCR positive COVID-19 patients were divided into 2 groups: control (n = 22) and standard treatment; ii. (n = 18) - Standard treatment + combination of AFO-202 and N-163 beta glucans for 15 days.

Results

IL-6 levels significantly decreased in the treatment group on day 7 (P = 0.03) but not by day 15 (P = 0.30). CRP levels in the treatment group decreased at day 7 (5.53 ± 8.21 mg/L) compared to baseline but showed no significant difference from the control group (4.91 ± 12.54 mg/L, P = 0.98). At day 15, CRP levels remained lower in the treatment group (5.42 ± 10.41 mg/L) but increased in the control group (14.0 ± 37.16 mg/L), with no significant difference (P = 0.52). Ferritin levels dropped significantly in the treatment group by day 15 (from 560.58 ± 537.30 ng/mL to 127.51 ± 215.91 ng/mL) but increased in the control (P = 0.98). D-dimer levels decreased in the treatment group by day 15 but were not significantly different from controls (P = 0.56).

Conclusion

These results indicate that while co-supplementation with AFO-202 and N-163 beta-glucans led to improvement in CRP, ferritin, and IL-6 levels in COVID-19 patients, only the reduction in IL-6 levels on day 7 reached statistical significance. Further long-term multicentric clinical research is warranted to validate the potential of these supplements as treatment adjuncts, for addressing inflammation in COVID-19, especially in vulnerable populations infected with emerging SARS-CoV-2 variants.

Factors affecting neutrophil functions during sepsis: human microbiome and epigenetics

Sepsis is a severe disease that occurs when the body's immune system reacts excessively to infection. The body's response, which includes an intense antibacterial reaction, can damage its tissues and organs. Neutrophils are the major components of white blood cells in circulation, play a vital role in innate immunity while fighting against infections, and are considered a feature determining sepsis classification. There is a plethora of basic research detailing neutrophil functioning, among which, the study of neutrophil extracellular traps is providing novel insights into mechanisms and treatments of sepsis. This review explores their functions, dysfunctions, and influences in the context of sepsis. The interplay between neutrophils and the human microbiome and the impact of DNA methylation on neutrophil function in sepsis are crucial areas of study. The interaction between neutrophils and the human microbiome is complex, particularly in the context of sepsis, where dysbiosis may occur. We highlight the importance of deciphering neutrophils' functional alterations and their epigenetic features in sepsis because it is critical for defining sepsis endotypes and opening up the possibility for novel diagnostic methods and therapy. Specifically, epigenetic signatures are pivotal since they will provide a novel implication for a sepsis diagnostic method when used in combination with the cell-free DNA. Research is exploring how specific patterns of DNA methylation in neutrophils, detectable in cell-free DNA, could serve as biomarkers for the early detection of sepsis.

Beta 1,3-1,6 Glucans Produced by Two Novel Strains of Aureobasidium Pullulans Exert Immune and Metabolic Beneficial Effects in Healthy Middle-aged Japanese Men: Results of an Exploratory Randomized Control Study

Objectives

In this pilot study, we have evaluated the specific metabolic and immune-related benefits of the AFO-202 strain and N-163 strain of black yeast Aureobasidium pullulans-produced beta 1,3-1,6 glucan 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.

Results

Decrease in HbA1C and glycated albumin (GA), 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 between pre- and post-treatment. Decrease in total and LDL cholesterol, a decrease of CD11b, serum ferritin, galectin-3 and fibrinogen were profound in Group II between pre- and post-treatment. However, there was no statistically significant difference between day 21 and day 35 among the groups.

Conclusion

This outcome warrants larger clinical trials to explore the potentials of these safe food supplements in the prevention and prophylaxis of diseases due to dysregulated metabolism, such as fatty liver disease, and infections such as COVID-19 in which balanced immunomodulation are of utmost importance, besides their administration as an adjunct to existing therapeutic approaches of both communicable and non-communicable diseases.