Six Weeks of Baker's Yeast β-Glucan Supplementation Reveals Unique Immune Maturation mRNA Signature: Implications for Immunity?

Baker's yeast beta-glucan (BYBG) supplementation significantly affected 42 mRNAs across 21 annotated immune pathways over 6 weeks.

• A total of 785 mRNAs were analyzed using the NanoString nCounter platform and Nanotube software (R v3.3.2).
• 42 mRNAs were significantly affected by BYBG at various time points.
• The 21 annotated pathways included antigen presentation, apoptosis, B cell memory, cell cycle, chemokine signaling, cytotoxicity, DAP12 signaling, hypoxia response, IL-1 signaling, IL-10 signaling, MAPK signaling, myeloid immune response, NF-kB signaling, NK activity, Notch Signaling, PD1 signaling, Senescence/Quiescence, T cell checkpoint signaling, TCR signaling, TLR signaling, and TNF signaling.
• Blood samples were collected at 0, 2, 4, and 6 weeks.

The study used an escalating dose design for BYBG supplementation over 6 weeks.

• N = 20 participants were randomized into BYBG or placebo groups in this exploratory study.
• BYBG dosing was escalated in three phases: weeks 0–2 = 50 mg/d, weeks 2–4 = 125 mg/d, and weeks 4–6 = 250 mg/d.
• The study design was described as exploratory with a small sample size.

The observed mRNA expression changes were hypothesized to underlie previously reported improvements in immune function with BYBG supplementation.

• The authors state it is 'reasonable to speculate that the observed mRNA and associated pathways may underlie previously reported improvements in immune function with BYBG.'
• Prior literature has reported that BYBG supplementation improves 'various aspects of immune system function, readiness, and response.'
• The mRNA signatures identified span pathways related to both innate and adaptive immune responses.
• This was an exploratory study, suggesting findings are preliminary and hypothesis-generating.

The study identified a unique immune maturation mRNA signature associated with BYBG supplementation at rest.

• Changes in mRNA expression were assessed at rest (not following an immune challenge or exercise stimulus).
• Pathways affected included both signaling pathways (e.g., NF-kB, MAPK, TLR, TCR, TNF signaling) and functional immune categories (e.g., cytotoxicity, NK activity, B cell memory, T cell checkpoint signaling).
• Senescence/Quiescence and PD1 signaling were among the pathways identified, suggesting effects on immune cell aging and inhibitory checkpoint regulation.
• The mRNA signature was described as 'unique,' implying a distinct pattern not previously characterized for BYBG.