๐ก This study systematically assessed the distribution and ecological implications of amino acid auxotrophies within the human gut microbiome.
๐ Metabolic cross-feeding interactions among coexisting genotypes were proposed as a potential source for amino acids, underscoring the ecological relevance of auxotrophies in the human gut microbiome.
๐ Methods:
Metabolomic Analysis: Metabolite profiles were obtained from stool samples to determine the metabolic landscape of the human gut, including the presence of amino acids.
Metagenomic Analysis: Metagenomic sequencing was performed on gut microbiome samples to identify the genetic traits of various microbial species.
Metabolic Modeling: Genome-scale metabolic models were constructed to predict auxotrophies in different microbial strains.
Association Analysis: Associations between auxotrophy frequencies and microbial diversity, stability, and their contribution to the human metabolome were investigated.
Key Findings:
Ubiquity of Amino Acid Auxotrophies: Amino acid auxotrophies are widespread in the human gut microbiome, with tryptophan auxotrophy being the most common. Remarkably, essential amino acids for both microbes and the human host exhibit higher auxotrophy frequencies.
Potential Sources of Amino Acids: Dietary sources alone are unlikely to account for the observed high frequencies of amino acid auxotrophies in the colon microbiome. Cross-feeding interactions between microbial strains, where prototrophic bacteria provide essential amino acids to auxotrophic counterparts, are suggested as a potential source.
Promotion of Microbiome Diversity and Stability: A positive association is observed between auxotrophy frequencies and microbiome diversity. Microbiomes with more auxotrophic members tend to display increased stability over time, emphasizing the role of metabolic complementarity and cross-feeding interactions in maintaining community structure.
Implications for Host-Microbiome Metabolism: Specific amino acid auxotrophies are linked to the profile of fermentation by-products, such as butyrate, acetate, and propionate. Associations between auxotrophies and human metabolites, including phenylic and indolic compounds, suggest that these auxotrophic gut bacteria contribute to the host’s metabolome.
๐ Amino acid auxotrophies in the human gut microbiome are not solely dependent on dietary sources but may arise from cross-feeding interactions among microbial strains. These auxotrophies are associated with greater microbiome diversity and stability, factors indicative of a healthy gut microbiome.
๐ This comprehensive study sheds light on the prevalence and ecological importance of amino acid auxotrophies in the human gut microbiome. The findings highlight their potential role in promoting microbiome diversity and stability, which may have implications for maintaining a healthy gut microbiome.
Moreover, the study suggests that metabolite cross-feeding networks contribute to the stability and diversity of the gut microbial community, offering insights for potential personalized treatment strategies targeting ecological interactions among gut microorganisms.
Link to the article : https://tinyurl.com/269jps56
