Short-Chain Fatty Acids Modulate Healthy Gut Microbiota Composition and Functional Potential

Area of Science:

• Microbiology
• Metabolomics
• Human Gut Microbiome Research

Background:

• Human gut microbiota's metabolic capacity for short-chain fatty acids (SCFAs) and host effects are well-studied.
• Limited data exists on how SCFAs produced by gut bacteria influence community structure and function via cross-feeding.

Purpose of the Study:

• To investigate the in vitro potential of SCFAs to modulate human gut microbiota.
• To understand SCFA-driven cross-feeding interactions and their impact on microbial community dynamics.

Main Methods:

• Anaerobic fecal cultivation in chemically defined media supplemented with nine different SCFAs.
• Analysis of gut microbial community structure using 16S rRNA sequencing.
• Evaluation of microbial function through genome reconstruction analysis.

Main Results:

• Each SCFA demonstrated unique modulatory effects on the relative abundance of bacterial taxa.
• SCFA supplementation led to coherent changes in closely related phylotypes, with some strain-dependent exceptions.
• Genome reconstruction indicated functional implications, including potential negative feedback mechanisms in some SCFA-producing bacteria.

Conclusions:

• SCFAs act as crucial modulators of gut microbiota, influencing bacterial fitness and community structure through cross-feeding.
• These findings are vital for identifying prebiotics that can elevate specific SCFAs for therapeutic purposes.
• SCFA consumers are recognized as key players in the overall metabolic flux of bacterial fermentation.