Key bacterial taxa and metabolic pathways affecting gut short-chain fatty acid profiles in early life

Area of Science:

• Microbiology
• Human Physiology
• Metabolomics

Background:

• Infant gut microbiota development is crucial for lifelong health.
• Short-chain fatty acids (SCFAs) are key metabolites mediating microbiota-host interactions.
• Understanding early life SCFA patterns and their microbial origins is essential.

Purpose of the Study:

• To identify distinct patterns of SCFA profiles in early infant gut microbiota.
• To investigate the relationships between these SCFA patterns and the gut microbiota composition.
• To explore the microbial pathways involved in SCFA production, particularly butyrate and formate.

Main Methods:

• Longitudinal analysis of 1048 fecal samples from 12 infants over the first two years of life.
• Quantification of SCFAs (acetate, propionate, butyrate, lactate, succinate, formate).
• 16S rRNA gene sequencing for microbiota profiling and analysis of microbial gene expression related to fucose metabolism.

Main Results:

• Three distinct SCFA progression phases were identified: early (low acetate, high succinate), middle (high lactate, formate), and late (high propionate, butyrate).
• Faecal butyrate correlated with increased Clostridiales and breastfeeding cessation, with specific Clostridiales species utilizing the acetyl-CoA pathway being key producers.
• Gut formate was associated with infant-type Bifidobacterial species, utilizing human milk oligosaccharide (HMO)-derived fucose as a substrate, with identified upregulated genes for fucose utilization.

Conclusions:

• Early life gut microbiota development exhibits dynamic SCFA profiles with distinct phases.
• Specific bacterial taxa, particularly Clostridiales and Bifidobacteria, play significant roles in producing key SCFAs like butyrate and formate.
• Understanding these early life SCFA-microbiota relationships provides insights for developing strategies to modulate lifelong health through microbial interventions.