Human Microbiome Alterations in Antarctic Isolated, Confined, and Extreme (ICE) Environments: A Systematic Review and...

Antarctica is one of the most extreme and isolated environments on Earth, serving as a natural laboratory for studying human physiological and microbial adaptation under stress. This systematic review and meta-regression evaluated how exposure to Antarctica's isolated, confined, and extreme (ICE) environments impacts the human microbiome, considering environmental and behavioral factors that may modulate these alterations. Following PRISMA guidelines and being registered with PROSPERO (CRD42024558423), comprehensive searches were conducted in PubMed, Scopus, Embase, Cochrane, and LILACS without language or date restrictions. Seven studies conducted between 2014 and 2024, enrolling 77 healthy participants in total, investigated oral, gut, or skin microbiota changes under Antarctica's ICE conditions at field camps, research stations, or shipboard environments. The findings suggest that ICE environments could induce measurable changes in microbial composition, relative abundance, and diversity across gut, oral, and skin sites, with age, type of accommodation, and sampling site emerging as significant predictors. Specifically, older individuals and those stationed at research bases exhibited greater odds of microbial alterations, while the gut microbiota showed greater stability compared to skin and oral sites. Although some studies explored the effects of probiotic supplementation and physical activity as modulators, evidence remains limited. The review highlights that environmental stressors such as confinement, duration of stay, extreme climate, diet, and physical exertion may collectively influence microbiome dynamics. These findings highlight the influence of age, accommodation type, and sampling site on microbial shifts in ICE environments, while underscoring the need for standardized longitudinal studies to clarify the biological and operational relevance of these changes.