Gut microbiota play a crucial role in maintaining human health by regulating digestion, metabolism, and immune functions. Microgravity during spaceflight has been shown to significantly alter gut microbiota composition and function, posing potential risks to astronaut health on long-duration missions. Recent studies have revealed shifts in microbial diversity, changes in community structure, alterations in metabolic activity, and increased prevalence of stress-tolerant species under spaceflight and simulated microgravity conditions. Specific markers, such as the Firmicutes/Bacteroidetes (F/B) ratio and short-chain fatty acid (SCFA) production, have been linked to metabolic disorders and immune dysfunction, while decreases in beneficial species like Lactobacillus and Bifidobacterium may compromise gut barrier integrity. These findings highlight the importance of developing targeted interventions, including probiotic supplementation, prebiotic or synbiotic formulations, and dietary modifications, to mitigate gut microbiota dysbiosis in space. Despite advances in culture systems and multi-omics approaches, challenges remain in replicating complex gut dynamics and ensuring astronaut safety during prolonged missions. Future research integrating advanced biotechnology, systems biology, and international collaborations, such as NASA’s GeneLab and ESA’s MELiSSA projects, is critical to deepen mechanistic understanding and translate findings into practical countermeasures. Overall, this review underscores the translational value of gut microbiota research under microgravity for both space health management and terrestrial medicine.
Sun et al. (Mon,) studied this question.