The influence of bioregenerative life-support system dietary structure and lifestyle on the gut microbiota: a 105-day ground-based space simulation in Lunar Palace 1

Understanding the dynamics of human gut microbiota in space is crucial in maintaining astronaut health. Long-duration and deep-space manned exploration will require the in situ regeneration of resources, which would be achieved by an artificial ecosystem, such as a bioregenerative life-support system (BLSS). Potential response of human gut microbiota to particular lifestyle and dietary structure experienced in a BLSS remains unclear. Here, we report how a BLSS impacts the gut microbiota during a 105-day study that took place in the Chinese Lunar Palace 1 (LP1). The three crewmembers were provided with high-plant and high-fibre diet, and they followed a fixed schedule including extensive labour in the plant cabin. The gut microbiota composition of the three crewmembers showed convergence and similar dynamic change. Increased diversity and abundance of Lachnospira, Faecalibacterium and Blautia indicated that the LP1 dietary structure and the lifestyle may be beneficial for the maintenance of healthy gut microbiome. A stronger impact was found from the gut microbiome to the environment compared with the opposite direction, suggesting the necessity of environmental pathogen control in BLSS.