# High-altitude mountaineering induces adaptive gut microbiome shifts associated with dietary intake and performance markers

## TL;DR

This study shows that high-altitude mountaineering changes gut microbes, linking these changes to diet and performance in climbers.

## Contribution

The study reveals adaptive gut microbiome shifts in alpinists linked to dietary intake and performance markers during high-altitude expeditions.

## Key findings

- High-altitude exposure caused significant shifts in gut microbiome composition and function.
- Greater microbiome shifts correlated with improved performance and richer baseline microbiomes.
- Microbiome changes were linked to blood markers related to nutrient metabolism and electrolyte balance.

## Abstract

This study examined how high-altitude exposure and expedition-specific dietary changes influence gut microbiome composition, functional pathways, and their relationships with performance and health markers in alpinists. Seventeen male mountaineers (age 30.29 ± 5.8 years) participating in multi-week expeditions (> 3,000 MASL) were assessed before and after their climbs. Assessments included dietary intake analysis, blood and urine biomarkers, aerobic and anaerobic performance tests, and metagenomic sequencing of the gut microbiome. Bioinformatic and statistical analyses evaluated changes in microbiome composition and function and their correlations with physiological and dietary parameters. High-altitude exposure was associated with significant shifts in gut microbial composition and functional capacity. While the total number of bacterial species and functions remained stable, the glucose degradation pathway increased post-expedition. Participants with greater microbiome shifts showed improved performance and had richer baseline microbiomes. Pre-expedition, certain microbial functions were associated with vitamin B₆ and C intake, while post-expedition correlations involved specific macronutrients and micronutrients. Additionally, some microbiome changes correlated with blood markers, indicating links to nutrient metabolism and electrolyte balance. The gut microbiome of alpinists adapts to extreme environmental stress and dietary changes, influencing metabolic, immune, and performance-related processes. Optimizing dietary strategies to support a beneficial microbiome profile may enhance resilience and performance in challenging high-altitude environments.

The online version contains supplementary material available at 10.1038/s41598-025-22848-9.