With the advancement of deep space exploration, astronauts’ long-term on-orbit health has gained growing attention. Extreme spaceflight conditions (e.g., microgravity, radiation) induces adaptive changes in microbial physiology, gene expression and metabolism, potentially affecting astronaut health and mission safety. However, a systematic overview of this field remains insufficient. Relevant studies on the impact of spaceflight on microorganisms were retrieved from the Web of Science Core Collection database. A bibliometric analysis was conducted using CiteSpace (v6.2.R3, developed by Dr. Chaomei Chen, Drexel University, USA) and VOSviewer (v1.6.20, developed by Leiden University, Netherlands) to visually analyze collaborations among countries/regions, institutions, authors and co-cited authors, as well as patterns of keyword co-occurrence and keyword overlays. A total of 225 articles were analyzed. Publications in this field increased from 2000 to 2024, with a significant rise after 2006. The United States was the leading country; NASA was the top institution; and Venkateswaran Kasthuri was the most productive and highly cited author. The top three co-cited authors included Venkateswaran Kasthuri, Hashimoto Hirofumi, and Singh Nitin K. Astrobiology dominated in terms of publications and co-citations. Cited journals focused on “Molecular Biology and Genetics”. The most co-cited reference was about bacterial and fungal communities on the International Space Station. Keyword clustering highlighted themes such as Escherichia coli, spaceflight, biosynthesis, oxidative metabolism, and probiotics. Terms like sp.nov. and “identification” showed citation bursts, thus indicating a focus on microbial taxonomy. “Biosynthesis” and “probiotics” also gained attention, emphasizing microbial metabolic pathways and probiotic space applications. Space microbiology research is in a stage of rapid development, and its focus is shifting from basic observations of microbial behaviors to the analysis of molecular mechanisms and the exploration of protective applications. Key areas include the influence of long-duration spaceflight conditions on microbial gene expression, metabolism, and oxidative stress, as well as the benefits of probiotics. These findings can provide a reference for future research direction planning and the formulation of astronaut health protection strategies.
Li et al. (Wed,) studied this question.