[Hao, Z., Meng, C., Li, L. et al. Positive mood-related gut microbiota in a long-term closed environment: a multiomics study based on the “Lunar Palace 365” experiment. Microbiome 11, 88 (2023). https://doi.org/10.1186/s40168-023-01506-0] (https://microbiomejournal.biomedcentral.com/articles/10.1186/s40168-023-01506-0)

This is a summary of our DalMUG journal club discussion of this paper written by Monica Alvaro Fuss

Summary

This study evaluated correlations between gut microbiota and psychological changes inside a closed manned Bioregenerative Life Support system facility, dubbed the “Lunar Palace 360” mission. This experiment simulated a sustainable moon-based environment on Earth and aimed to identify new potential psychobiotics that may help maintain and improve psychological health of crew members. Alterations to gut microbiome composition appeared to revolve around four potential taxa: Bacteroides uniformis, Roseburia inulinivorans, Eubacterium rectale, and Faecalibacterium prausnitzii, which showed strong correlations with positive mood parameters. Metagenomic, metaproteomic and metabolomic analyses suggested that short-chain fatty acid production, amino acid metabolism related to key neurotransmitters, as well as taurine and cortisol metabolism likely play important roles is modulating mood through the gut-brain axis. Lastly, rats were subjected to anxiety- and depression-inducing protocols and were inoculated with 3 of the putative psychobionts, and these data appear to support their positive regulatory effects and mechanisms.

Below are the key points that came up during our discussion.

Points of discussion

• Mood patterns of different crewmembers in different groups.

• The term “psychobiont” and its relevance in the literature.

• Do metagenomic data correlate with taxonomic profiles?

• Data appear to strongly support conclusions, but may have been cherry-picked.

• Additional controls for the animal experiments and verifying the colonization of inoculated strains.