Sodium butyrate

What it isThe sodium salt of butyric acid — a short-chain fatty acid produced by colonic fermentation of fiber, and a histone deacetylase inhibitor.

Why this oneIt is the primary fuel of colonocytes, which is the rationale behind its use as a gut-health supplement and behind interest in the fiber-microbiome-butyrate axis.

What limits itIt is a supplement, not an approved drug: oral butyrate is largely absorbed before reaching the colon, the smell is notorious, and clinical evidence remains thin.