The Effect of a Multi-strain Probiotic on Acclimatization to High Altitude

The goal of this study is to learn if the probiotic SLAB51 (Sivomixx800®) works to enhance acclimatization to high altitude in humans. The main questions it aims to answer are:

Does SLAB51 improve oxygen saturation during high-altitude exposure? Researchers will compare SLAB51 to a placebo (a substance that contains no probiotic) to see if SLAB51 works to enhance high-altitude acclimatization.

Participants will:

Take SLAB51 or a placebo three times daily during two separate three-night acclimatization periods at high altitude, spaced at least six weeks apart.

Complete baseline measurements at sea level. Visit the high-altitude Barcroft Station (3,801 m) at the University of California White Mountain Research Center for physiological measurements and assessments.

Undergo assessments including oxygen saturation, ventilation, heart rate, blood pressure, sleep studies, cognitive assessments, exercise capacity, Acute Mountain Sickness scores, and provide blood, fecal, and urine samples for advanced analyses.

Individuals will be recruited to participate in a double-blind, placebo controlled, cross-over study receiving placebo or the nutritional supplement probiotic SLAB51 (Sivomixx800®) during exposure to high altitude to test the effects of SLAB51 on high-altitude acclimatization.

Humans face significant physiological detriments when they ascend to high altitude due to hypobaric hypoxia, and physiological changes are crucial for acclimatization to this stressful environment. Currently, there are limited interventions to improve acclimatization to high altitude. The investigators conducting this study will test if the probiotic SLAB51 improves oxygen saturation and mitigates negative outcomes often experienced during acclimatization to high altitude through studies performed at sea level and at the high-altitude Barcroft Station (3,801 m) at the University of California White Mountain Research Center.

Preliminary studies indicate that ingestion of SLAB51 significantly improves oxygenation in humans during physical exercise in simulated altitude within a hypobaric chamber, in a pressurized airplane cabin during commercial flight, in premature born babies, and in COVID-19 patients. Here, the investigators explore whether ingestion of SLAB51 affects acclimatization to high altitude in healthy humans. Physiological measurements include oxygen saturation (O2 Sat or SpO2 during wakefulness and sleep, primary outcomes) as well as ventilation, heart rate, blood pressure, sleep studies, cognitive assessments, exercise capacity, measurement of the Acute Mountain Sickness score, and the collection of blood, fecal, and urine samples to further explored through transcriptomics, methylation, metabolomics, and proteomics. All measurements will be taken in up to 60 participants on two separate occasions separated by at least 6 weeks. Participants will complete all assessments, one baseline measurement obtained at sea level (0 - 300 m) and then twice during three-night acclimatization periods at Barcroft Station (3,801 m). At high altitude, participants will receive a treatment (placebo or SLAB51) upon arrival at Barcroft Station and then three times a day until departure from the high-altitude site. During the second portion of the study approximately six weeks later, participants will complete the same repeat assessments during a second three-night visit at Barcroft Station, where they will receive whichever treatment was not taken during the high-altitude exposure six weeks prior. Both participants and researchers performing the studies will be blinded to the treatment. Upon completion of the study, researchers will compare how participants acclimatized when they received SLAB51 versus when they received the placebo treatment.