A non-absorbed baker's yeast fibre that readies first-line defence cells. The consistent finding is a lighter load of cold symptoms under real physical or mental strain; outright prevention of infections is weaker. Mood, hay fever, and at higher doses blood pressure and waist size show smaller signals. Safety is the least contested part; most evidence comes from the seller. (Full Review)
| Marker | Target | Why |
|---|---|---|
| Serum (1→3)-Beta-D-Glucan | Below 60 pg/mL | Establishes an unsupplemented baseline so a later rise is interpretable |
| hs-CRP | Below 1.0 mg/L | Tracks the body-wide inflammatory state that trials selected for |
| White Blood Cell Count with Differential | 4.0–7.0 ×10⁹/L, neutrophils 2.0–4.5 ×10⁹/L | Confirms no unexpected shift in the cell populations being primed |
| Fasting Insulin and HOMA-IR | Insulin 2–5 µIU/mL; HOMA-IR below 1.5 | The endpoint that moved at the higher metabolic dose |
| HbA1c | 4.8–5.4% | Confirms whether an insulin-resistance change carries through to glucose control |
| Total IgE | Below 50 IU/mL | Relevant only when allergy is the target, and expected not to change |
| Salivary Secretory IgA | No established target range; change from the individual's own baseline | The mucosal barrier marker that rose after exercise in trial data |
| Serum 25-Hydroxyvitamin D | 40–60 ng/mL | Corrects a common confounder of winter infection rates before attributing change to the supplement |
Cadence: Baseline before starting; inflammatory and metabolic markers repeated at 12 weeks, then every 6–12 months while use continues. The fungal-marker baseline is re-checked only if a fungal workup becomes likely.