This 2021 review subject was effects of short-chain fatty acids produced by gut microbiota:
“SCFAs are the main players in the interplay between diet, microbiota, and health. SCFAs contribute to intestinal homeostasis and regulation of energy metabolism.
SCFAs regulate the blood–brain barrier and neuroimmunoendocrine functions. During gestation, SCFAs can cause epigenetic imprinting and protect against allergic airway disease.
Fiber reaching the colon is anaerobically fermented by gut bacteria, which produce SCFAs. Nondigestible polysaccharides are found in plant cell walls, and are further classified into soluble and nonsoluble dietary fibers.
A role for SCFAs in histone modification of tissues in the body was definitively shown by dietary supplementation of germ-free mice with microbially produced acetate, propionate, and butyrate. These SCFAs increased acetylation of histone H4 and H3 in a tissue-specific fashion.
Most research to date has focused on butyrate but unlike acetate and propionate, it is typically present in undetectable or very low concentrations in the body. SCFAs appear to influence health through three principal mechanisms:
- Altering levels of HAT [histone acetyltransferase] and HDAC [histone deacetylase] activity;
- Signaling by specific fatty acid-sensing GPCRs [G-protein-coupled receptors]; and
- Anti-inflammatory mechanisms in the periphery and tissues due to the first two mechanisms.”
https://www.cell.com/trends/microbiology/fulltext/S0966-842X(21)00035-4 “Microbial Regulation of Host Physiology by Short-chain Fatty Acids”