A 7-Week Summer Camp in Antarctica Induces Fluctuations on Human Oral Microbiome, Pro-Inflammatory Markers and Metabolic Hormones Profile.

Antarctic camps pose psychophysiological challenges related to isolated, confined, and extreme (ICE) conditions, including meals composed of sealed food. ICE conditions can influence the microbiome and inflammatory responses. Seven expeditioners took part in a 7-week Antarctic summer camp (Nelson Island) and were evaluated at Pre-Camp (i.e., at the beginning of the ship travel), Camp-Initial (i.e., 4th and 5th day in camp), Camp-Middle (i.e., 19th-20th, and 33rd-34th days), Camp-Final (i.e., 45th-46th day), and at the Post-Camp (on the ship). At the Pre-Camp, Camp-Initial, and Camp-Final, we assessed microbiome and inflammatory markers. Catecholamines were accessed Pre- and Post-Camp. Heart rate variability (HRV), leptin, thyroid stimulating hormone (TSH), and thyroxine (T4) were accessed at all time points. Students' t-tests or repeated-measures analysis of variance (one or two-way ANOVA) followed by Student-Newman-Keuls (post hoc) were used for parametric analysis. Kruskal-Wallis test was applied for non-parametric analysis. Microbiome analysis showed a predominance of Pseudomonadota (34.01%), Bacillota (29.82%), and Bacteroidota (18.54%), followed by Actinomycetota (5.85%), and Fusobacteria (5.74%). Staying in a long-term Antarctic camp resulted in microbiome fluctuations with a reduction in Pseudomonadota-a "microbial signature" of disease. However, the pro-inflammatory marker leptin and IL-8 tended to increase, and the angiogenic factor VEGF was reduced during camp. These results suggest that distinct Antarctic natural environments and behavioral factors modulate oral microbiome and inflammation.

A 32-day long fieldwork in Antarctica improves heat tolerance during physical exercise.

We evaluated the influence of a 32-day camping in Antarctica on physical performance and exercise-induced thermoregulatory responses. In Brazil, before and after the Antarctic camping, the volunteers performed an incremental exercise at temperate conditions and, two days later, an exercise heat stress protocol (45-min running at 60% of maximum aerobic speed, at 31°C and 60% of relative humidity). In Antarctica, core temperature was assessed on a day of fieldwork, and average values higher than 38.5°C were reported. At pre- and post-Antarctica, physiological (whole-body and local sweat rate, number of active sweat glands, sweat gland output, core and skin temperatures) and perceptual (thermal comfort and sensation) variables were measured. The Antarctic camping improved the participants' performance and induced heat-related adaptations, as evidenced by sweat redistribution (lower in the chest but higher in grouped data from the forehead, forearm, and thigh) and reduced skin temperatures in the forehead and chest during the exercise heat stress protocol. Notwithstanding the acclimatization, the participants did not report differences of the thermal sensation and comfort. In conclusion, staying in an Antarctic camp for 32 days improved physical performance and elicited physiological adaptations to heat due to the physical exertion-induced hyperthermia in the field.

Mapping research paths and perspectives over the fieldwork of human physiology in Antarctica: reflections on the integration of science, environment, and subjectivity.

We summarize and elaborate on the challenges of researching in the field of human health in Antarctica based on the conceptual and methodological specificities of a line of investigation that aims to study the human presence in Antarctica in all of its dimensions (biological, psychological, and socio-anthropological). Herein, we discuss the principal results and limitations of the research carried out by researchers of MEDIANTAR (Antarctic medicine, physiology, and anthropology) group of Programa Antártico Brasileiro in isolated, confined, and extreme environments over the last six years. Fieldwork has been carried out in remote research camps, Brazilian navy ships (Almirante Maximiano/H-41 and Ary Rongel/H-44), and Comandante Ferraz Antarctic Station. Adaptative responses to isolated, confined, and extreme environments were studied based on questionnaires, interviews, participative observation, biological samples, anthropometric, and physiological parameters. Our researchers face the unique situation of concomitantly working under the stressful living conditions that are the object of their investigation. A critical examination of the socio-methodological characteristics and challenges of this research niche indicates the need for exchanging the lessons learned and limitations of these practices with researchers in the humanities field, with attention to the human resources needs in multidisciplinary human-related studies.