Gut bacteria-derived 5-hydroxyindole is a potent stimulant of intestinal motility via its action on L-type calcium channels
Fig 1
Gut bacteria convert 5-HTP to 5-HI.
(A) From left to right: chromatograms showing bacterial conversion of 100 μM 5-HTP to 5-HI after 6 and 24 h of incubation of human fecal samples (upper panel). Lower panel: quantification of 5-HTP consumption (substrate; black circles) and 5-HI production (product; white circles) observed in High (n = 8), Intermediate (n = 4), and Non-Converters (n = 6). The raw data can be found in S1 Raw images. (B) Heatmap of 5-HI levels detected in the fecal samples of volunteers who administered 5-HTP tablets for 1 week, collected on Day 1 (first ingestion of 5-HTP tablet), Day 3, and Day 8 (1 day after last 5-HTP tablet was ingested). The numbers in the squares indicate fold change in 5-HI levels normalized to Day 0. The raw data used for quantification of A (lower panel) and B can be found in S1 Data. 5-HI, 5-hydroxyindole; 5-HTP, 5-hydroxytryptophan.