Advances in studying the onset and progression of ulcerative colitis (UC) suggest that both diet and microbiome play a critical role in the progression of disease, though no causal link has been found. Lactobacillus species found in the microbiome produce tyramine, a trace amine and known ligand for the G-protein coupled receptor Trace Amine Associated Receptor 1 (TAAR1). Tyramine also occurs naturally in the body as a byproduct of tyrosine metabolism, and it can be detected in certain food products produced by a variable subset of common microbiome organisms.