Positive mood-related gut microbiota in a long-term closed environment: a multiomics study based on the “Lunar Palace 365” experiment

Abstract

Background Psychological health risk is one of the most severe and complex risks in manned deep-space exploration and long-term closed environments. Recently, with the in-depth research of the microbiota–gut–brain axis, gut microbiota has been considered a new approach to maintain and improve psychological health. However, the correlation between gut microbiota and psychological changes inside long-term closed environments is still poorly understood. Herein, we used the “Lunar Palace 365” mission, a 1-year-long isolation study in the Lunar Palace 1 (a closed manned Bioregenerative Life Support System facility with excellent performance), to investigate the correlation between gut microbiota and psychological changes, in order to find some new potential psychobiotics to maintain and improve the psychological health of crew members. Results We report some altered gut microbiota that were associated with psychological changes in the long-term closed environment. Four potential psychobiotics (Bacteroides uniformis, Roseburia inulinivorans, Eubacterium rectale, and Faecalibacterium prausnitzii) were identified. On the basis of metagenomic, metaproteomic, and metabolomic analyses, the four potential psychobiotics improved mood mainly through three pathways related to nervous system functions: first, by fermenting dietary fibers, they may produce short-chain fatty acids, such as butyric and propionic acids; second, they may regulate amino acid metabolism pathways of aspartic acid, glutamic acid, tryptophan, etc. (e.g., converting glutamic acid to gamma–aminobutyric acid; converting tryptophan to serotonin, kynurenic acid, or tryptamine); and third, they may regulate other pathways, such as taurine and cortisol metabolism. Furthermore, the results of animal experiments confirmed the positive regulatory effect and mechanism of these potential psychobiotics on mood. Conclusions These observations reveal that gut microbiota contributed to a robust effect on the maintenance and improvement of mental health in a long-term closed environment. Our findings represent a key step towards a better understanding the role of the gut microbiome in mammalian mental health during space flight and provide a basis for future efforts to develop microbiota-based countermeasures that mitigate risks to crew mental health during future long-term human space expeditions on the moon or Mars. This study also provides an essential reference for future applications of psychobiotics to neuropsychiatric treatments.

Christensenella minuta interacts with multiple gut bacteria

“…Among the 11 MAGs exhibiting a positive correlation with SJ-2, Eubacterium sp. AM28-29, D. pneumosintes and Tractidigestivibacter scatoligene were predicted to have the highest correlation with SJ-2 (SCC > 0.9), T. scatoligenes , Limosilactobacillus fermentum , F. praussnitzii and Roseburia inulinivorans were of great interest as potential probiotics in previous researches ( Lopez-Siles et al, 2017 ; Sankaranarayanan et al, 2021 ; Hao et al, 2023 ; Ozen et al, 2023 ). As a comparison, several species of Bifidobacterium and Bacteroidetes exhibited negative associations with SJ-2 ( Figure 4 , Supplementary Table S13 ).…”

Multi-omics reveal microbial determinants impacting the treatment outcome of antidepressants in major depressive disorder

“…It is intriguing to note that E. rectale , a core gut commensal species, consistently showed higher abundance in R group compared to NR group at three visit weeks, and its abundance was positively correlated with species richness at baseline and week 12 (Figure S 4 E&F). As a strict anaerobe, E. rectale can promote host gut health by producing butyrate and other SCFAs from indigestible fibers [ 49 ], and has recently been identified as psychobiotics to maintain and improve mental health [ 50 ]. Similar to the situation of spore-forming bacteria, the abundance of most sporulation genes (11 out of 22 sporulation genes that occur in at least in 20% of baseline samples) was higher in R group than in NR group (q < 0.1, Fig.…”

Mouse intestinal microbiome modulation by oral administration of a GABA-producing Bifidobacterium adolescentis strain

“…Remarkably, several gut commensal species apart from bifidobacteria correlated positively with serum GABA levels. Among these is very notable the presence of several commensal and beneficial taxa, including Roseburia , a well-known butyrate producer that includes species proposed as potential psychobiotics ( 57 ) and with the capacity to produce serotonin ( 58 ).…”