The Effect of a Multi-strain Probiotic on Acclimatization to High Altitude
NCT Number: NCT06552806
Status: ACTIVE_NOT_RECRUITING
Study Type: INTERVENTIONAL
Phases: NA
Conditions: Probiotics
Interventions: DIETARY_SUPPLEMENT: SLAB51
Sponsor: University of California, San Diego
Sex: ALL
Age: ADULT, OLDER_ADULT
Enrollment: 17
Study Design: Allocation: RANDOMIZED|Intervention Model: CROSSOVER|Masking: SINGLE (OUTCOMES_ASSESSOR)|Primary Purpose: TREATMENT
Start Date: 2023-06-01
Completion Date: 2026-10
Locations: White Mountain Research Station, Bishop, California, 93514, United States|University of California, San Diego, La Jolla, California, 92093, United States

Summary:
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.

Primary Outcome Measures: Oxygen saturation, The effects of treatment group (probiotic or placebo) and timepoint on daytime SpO2 and mean nocturnal SpO2 will be determined by two-way analysis of variance (ANOVA) with a Bonferroni post hoc test., At sea level (one day, one night) and all four days and three nights of the study at high altitude
Secondary Outcome Measures: Hypoxic ventilatory response, Changes in ventilation due to the decrease of oxygen saturation (10%) and/or increase in carbon dioxide (5mmHg), At sea level (one day) and one day at high altitude|Heart rate, Heart rate measurement, At sea level (one day, one night) and all four days at high altitude|Heart rate variability, Values of high frequency-low frequency ratio (HF/LF) of volunteers administered with SLAB51, At sea level (one day, one night) and all four days at high altitude|Blood pressure, Blood pressure measurement, At sea level (one day, one night) and all four days at high altitude|Sleep oxygen saturation, Oxygen levels during sleep, At sea level (one night) and all three nights of the study at high altitude|Sleep apnea hypopnea index, Number of times breathing stops and leads to a decrease of 3% oxygen saturation, At sea level (one night) and all three nights of the study at high altitude|Sleep oxygen desaturation index, How often and how much a person's blood oxygen saturation drops (at least 4%) during sleep, At sea level (one night) and all three nights of the study at high altitude|Sleep duration, How many hours and minutes a person sleeps during the night, At sea level (one night) and all three nights of the study at high altitude|Cancellation Pictures cognitive test, A timed, tablet-based test of selective attention and inhibitory control, Two consecutive days at sea level, each of the four days at high altitude, and another time at sea level 1-2 weeks after returning from high altitude.|Contrast Sensitivity cognitive test, Measures the ability to distinguish between fine increments of light and dark (contrast), Two consecutive days at sea level, each of the four days at high altitude, and another time at sea level 1-2 weeks after returning from high altitude.|Digits-in-Noise cognitive test, Presents trials of three sequential spoken digits against a broad-band, speech-shaped masker. The outcome measure is the threshold noise tolerance., Two consecutive days at sea level, each of the four days at high altitude, and another time at sea level 1-2 weeks after returning from high altitude.|Spatial Release from Masking cognitive test, Tests the ability to distinguish speech from competing speech using headphones and virtual spatial locations., Two consecutive days at sea level, each of the four days at high altitude, and another time at sea level 1-2 weeks after returning from high altitude.|Trail Making cognitive test, A measure of visual attention and task switching ability with outcome measures of response time and accuracy., Two consecutive days at sea level, each of the four days at high altitude, and another time at sea level 1-2 weeks after returning from high altitude.|Oxygen saturation in submaximal exercise, Measurement of oxygen saturation during the final 30 seconds of submaximal exercise on a stationary bike, At sea level (one day) and one day at high altitude|Lactate following submaximal exercise, Measurements of lactate following submaximal exercise on a stationary bike, At sea level (one day) and one day at high altitude|Acute Mountain Sickness Score, Questionnaire to gauge how a person feels at high altitude. It defines AMS as the presence of headaches in addition to three other symptoms, including gastrointestinal symptoms, fatigue/weakness, and dizziness/lightheadedness. Each symptom is appointed a point on a scale from 0 to 3, with 0 being no effect and 3 being severe. A total score of 3 or greater, with the presence of headaches, in a setting of rapid ascent to high altitude, is diagnosed as acute mountain sickness., At sea level (one day) and all four days of the study at high altitude