Fluid shifts are main drivers for microgravity simulation-induced immune-physiological changes: findings from the VIVALDI studies
Year: 2026
Type: article
Abstract: Microgravity strongly affects human physiology during spaceflight. Biological sex has not yet been sufficiently considered as a variable for spaceflight deconditioning. The VivalDI studies investigated physiological systems affected by 5-days dry immersion (DI) in females and males, with a focus on immune changes in this report. In both sexes proportions of peripheral granulocytes and NK cells were elevated during DI and T-cell numbers were reduced. Leukocyte activation and cytokine levels were moderately affected. Females showed a higher Torque-Teno-virus shedding at the end of DI. Noradrenaline concentrations increased during the study with sex-specific patterns. Hemodynamics suggest that immunological changes were caused by DI-induced fluid shifts. Moreover, male study participants' patterns were compared to a historical data set from a 5-days head-down-tilt bed rest (HDT-BR) study. Changes in leukocyte proportions and body fluid indicators were stronger in DI versus HDT-BR. These analyses indicate that fluid shifts primarily drive intervention-related immune-physiological differences, independent of biological sex. ClinicalTrials.gov, TRN: NCT05043974 and NCT05493176.
Source: npj Microgravity
Authors: Dominique Moser, Marie-Pierre Bareille, Angelique van Ombergen, Marion Hoerl, Federico D´Amico, Matthias Feuerecker, Christopher Dächert, Sandra Matzel, Adrien Robin, Nastassia Navasiolava, Marc-Antoine Custaud, Alexander Choukér, Alexander Choukér, On behalf of the Members of the VivalDI -study and Dry Immersion expert group, A. Robin, M.-A. Custaud, N. Navasiolava, C. Laurens, A. Bergouignan, L. Vico, A. Chopard, A. Pav-Le Traon, A. Choukér, A. Choukér, D. Moser, D. A. Green, Michael Tipton, P. Denise, H. Normand, S. Blanc, E. Rosnet
Institutions: LMU Klinikum, Ludwig-Maximilians-Universität München, European Space Agency, Max-von-Pettenkofer-Institut für Hygiene und Medizinische Mikrobiologie, Centre National de la Recherche Scientifique, Inserm, Centre Hospitalier Universitaire d'Angers, Mitochondrial and Cardiovascular Physiopathology, Université d'Angers, Texas A&M University, Université Toulouse III - Paul Sabatier, Université Jean Monnet, Université de Montpellier, Centre Hospitalier Universitaire de Toulouse, King's College London, University of Portsmouth, Université de Caen Normandie, Université de Strasbourg, Université de Reims Champagne-Ardenne
Language: English
Subfield: Physiology
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $3,690
OpenAlex ID: W7129016320