High-Altitude-Induced alterations in Gut-Immune Axis: A review

ABSTRACT

High-altitude sojourn above 8000 ft is increasing day by day either for pilgrimage, mountaineering, holidaying or for strategic reasons. In India, soldiers are deployed to these high mountains for their duty or pilgrims visit to the holy places, which are located at very high altitude. A large population also resides permanently in high altitude regions. Every year thousands of pilgrims visit Holy cave of Shri Amarnath ji, which is above 15 000 ft. The poor acclimatization to high altitude may cause alteration in immunity. The low oxygen partial pressure may cause alterations in gut microbiota, which may cause changes in gut immunity. Effect of high altitude on gut-associated mucosal system is new area of research. Many studies have been carried out to understand the physiology and immunology behind the high-altitude-induced gut problems. Few interventions have also been discovered to circumvent the problems caused due to high-altitude conditions. In this review, we have discussed the effects of high-altitude-induced changes in gut immunity particularly peyer's patches, NK cells and inflammatory cytokines, secretary immunoglobulins and gut microbiota. The published articles from PubMed and Google scholar from year 1975 to 2017 on high-altitude hypoxia and gut immunity are cited in this review.

KEYWORDS:

• Cytokines
• gut
• high altitude
• inflammation
• Peyer's patches
• sIgA

Conflict of interest statement

Authors report no conflict of interest.

Acknowledgments

Authors thank Defence Research & Development Organization (DRDO), Ministry of Defence, Government of India, for financial support in the form of project DIP-265. KK thanks DRDO for providing the fellowship in the form of junior and senior research fellowship.

Additional information

Funding

Defence Research and Development Organization, India(DIP265)