Fluid shifts are main drivers for microgravity simulation-induced immune-physiological changes: findings from the VIVALDI studies
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.
Authors
- Mike Tipton (ORCID: https://orcid.org/0000-0002-7928-8451)
- Fabián Amico (ORCID: https://orcid.org/0000-0002-3958-124X)
- Dominique Moser (ORCID: https://orcid.org/0000-0002-3156-2976)
- Sandra Matzel
- Marion Hoerl
- Adrien Robin (ORCID: https://orcid.org/0000-0001-7879-3715)
- Angelique Van Ombergen (ORCID: https://orcid.org/0000-0002-3977-4279)
- Matthias Feuerecker (ORCID: https://orcid.org/0000-0002-9773-083X)
- Nastassia Navasiolava (ORCID: https://orcid.org/0000-0002-6405-6498)
- Alexander Choukèr (ORCID: https://orcid.org/0000-0002-0133-4104)
- Marie-Pierre Bareille
- M.-A. Custaud
- N. Navasiolava
- E. Rosnet
- A. Pav-Le Traon
- A. Robin
- P. Denise
- On behalf of the Members of the VivalDI -study and Dry Immersion expert group
- D. A. Green
- A. Bergouignan
- A. Chopard
- S. Blanc
- C. Laurens
- Christopher Dächert
- A. Choukér
- Marc-Antoine Custaud
- H. Normand
- D. Moser
- L. Vico
Institutions
- Centre National de la Recherche Scientifique (FR)
- Université Toulouse III - Paul Sabatier (FR)
- Inserm (FR)
- King's College London (GB)
- Université de Montpellier (FR)
- Centre Hospitalier Universitaire de Toulouse (FR)
- Texas A&M Health Science Center (US)
- European Space Research and Technology Centre (NL)
- Université d'Angers (FR)
- University of Colorado Anschutz Medical Campus (US)
- University of Portsmouth (GB)
- Université de Strasbourg (FR)
- Ludwig-Maximilians-Universität München (DE)
- Université Jean Monnet (FR)
- University of Colorado Denver (US)
- Bryan College (US)
- Université de Reims Champagne-Ardenne (FR)
- Université de Caen Normandie (FR)
Publication Details
- Journal
- npj Microgravity
- Published
- 2026-02-16
- DOI
- https://doi.org/10.1038/s41526-025-00555-z
- Primary Topic
- Spaceflight effects on biology
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- European Space Agency
- Bundesministerium für Wirtschaft und Technologie
- Centre National d’Etudes Spatiales
- Deutsches Zentrum für Luft- und Raumfahrt