Microbiome dynamics during the HI-SEAS IV mission, and implications for future crewed missions beyond Earth

Abstract

BackgroundHuman health is closely interconnected with its microbiome. Stable microbiomes in, on and around the human body will be key for safe and successful long-term space travel. However, longitudinal dynamics of microbiomes inside confined built environments are still poorly understood. Herein we used the Hawaii Space Exploration Analog and Simulation IV (HI-SEAS IV) mission, a one year-long isolation study, to investigate microbial transfer between crew and habitat, in order to understand adverse developments which might occur in an outpost on the Moon or Mars in the future.ResultsLongitudinal profiles of the 16S rRNA gene revealed significant differences in microbial diversity and composition between samples of the built environment and its crew. While microbial profiles from individual crew members were highly dynamic, the microbiome on built environment surfaces remained more stable. Especially within the first 200 days, archaeal signatures of Methanobrevibacter were regularly transferred between crew members, but did not impact the microbiome on habitat surfaces. In contrast to a rather stable microbial diversity recovered from surfaces of the habitat, microbial diversity from the crew’s skin increased over time. Quantitative observations based on qPCR supported observations of dissimilarity between the built environment and its crew and was also used to track the propagation of antimicrobial resistances in the habitat. Together with functional and phenotypic predictions, quantitative and qualitative data both supported the observation of a delayed longitudinal homogenization between the crew and their habitat, that was mainly caused by the hygiene infrastructure.ConclusionsThe study highlights main routes of microbial transfer, interaction of its crew and origins of microbial dynamics in an isolated set-up. We identified key targets of microbial monitoring, and emphasize the need for defined baselines of microbiome diversity and abundance on surfaces and skin. Targeted manipulation to counteract adverse developments of the microbiome will be a highly important strategy to ensure safety during future space endeavors.

First-Year Dynamics of the Anaerobic Microbiome and Archaeome in Infants Oral and Gastrointestinal Systems

“…The analysis of the 16S rRNA gene amplicon data was performed using QIIME2 (27) 2021.1-12 following the previously outlined methodology (28). Quality filtering was performed with the DADA2 algorithm (29) which involved merging paired-end reads, truncation (-p-trunc-len-f 200 -p-trunc-len-r 150) and denoising for the generation of amplicon sequence variants (ASVs).…”

Microbiota and probiotics: chances and challenges – a symposium report

“…Another Mars simulation model is the Hawai'i Space Exploration Analog and Simulation (HI-SEAS) mission (Mahnert et al, 2021). This involved a team of astronauts spending 4-12 months in a 111 m 2 module, during which time samples were taken from different areas of the module and the crew's skin and faeces.…”

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“…Experts have estimated that the most significant risks for space exploration missions are trauma, hemorrhagic shock, and infections. [2][3][4] To some extent, the likelihood of medical events can be estimated from analog ground populations, both military and civilian, and data gathered during human spaceflight experience. 2,5,6 For example, the risk of lower limb fracture has been estimated at 0.046 event per Mars mission (950-day mission for a crew of six).…”