Effects of OXXYSLAB Probiotic Supplementation on Blood Oxygenation and Hypoxic Symptoms in Healthy Individuals: A Controlled Normobaric Hypoxia Trial

Background: OXXYSLAB, a high-dose, multi-strain probiotic, has shown promise in pathological hypoxemia but remains untested under acute normobaric hypoxia (NH) in healthy volunteers. We evaluated whether OXXYSLAB alters peripheral oxygen saturation (SpO2) and alleviates hypoxia-related symptoms in healthy adults exposed to NH.Methods: In two randomized, double-blind, crossover phases, young adults were exposed to similar to 13.5% inspired O2 for 1 hour (Phase 1: n = 12, 21.6 +/- 1.3 years, body mass index [BMI] = 23.2 +/- 2.8 kg/m2) or 40 minutes (Phase 2: n = 20, 21.7 +/- 1.5 years, BMI = 22.9 +/- 3.2 kg/m2). Participants received either a single (8 x 1011 colony-forming unit [CFU]) or double (1.6 x 1012 CFU) dose of OXXYSLAB or matched placebo in randomized order.Results: NH induced the expected SpO2 decrease (Phase 1: 90.0 +/- 2.1%; Phase 2: 86.7 +/- 2.9%), with no significant effect of probiotic supplementation on SpO2. In Phase 1, a trend toward lower heart rate (Delta = -3.2 bpm) under OXXYSLAB approached significance (p = 0.053); no effect was seen in Phase 2. Notably, headache incidence under probiotic conditions was reduced by 50% (Phase 1) and 62.5% (Phase 2) compared to placebo (p = 0.046 and p = 0.059, respectively).Conclusion: While OXXYSLAB did not enhance systemic oxygenation during acute NH, it significantly attenuated headache, a common symptom of hypoxia. Further research should assess its efficacy under prolonged or clinical hypoxemic conditions.