Short-chain fatty acids: linking diet, the microbiome and immunity

Area of Science:

• Microbiology
• Immunology
• Metabolomics

Background:

• Short-chain fatty acids (SCFAs) like butyrate, propionate, and acetate are key microbial metabolites.
• Their availability is influenced by environmental factors such as diet and antibiotic use, which shape gut microbiota.
• SCFAs are integral to host-microbe interactions and physiological regulation.

Purpose of the Study:

• To elucidate the multifaceted roles of SCFAs in regulating epithelial barrier function and immune responses.
• To explore the impact of SCFAs on both mucosal and systemic immunity.
• To highlight the implications of SCFA dysregulation in various immune-mediated diseases.

Main Methods:

• Review of existing literature on SCFA metabolism and function.
• Analysis of conserved signaling pathways involving G protein-coupled receptors and histone deacetylase activity.
• Examination of SCFA effects on immune cell differentiation and function.

Main Results:

• SCFAs regulate epithelial barrier integrity and immune cell differentiation (e.g., T cells, B cells).
• Butyrate exhibits anti-inflammatory properties through direct effects on various immune cells.
• Intestinally derived SCFAs influence immunity in extra-intestinal sites like the liver, lungs, and brain.

Conclusions:

• SCFAs are critical regulators of immune homeostasis, impacting both local and systemic immunity.
• Dysregulation of SCFA availability is linked to a spectrum of immune-mediated disorders.
• Engineering butyrogenic bacteria and understanding microbial ecology offer potential therapeutic strategies for immune diseases.