Research

Hormonal

Gut microbiota modulate appetite by influencing the metabolism of Tryptophan (Trp) into serotonin (5-HT) and indole derivatives, which regulate satiety and intestinal permeability.

Tryptophan metabolism by gut bacteria influences serotonin levels, which affect appetite. However, because results are inconsistent and depend on dosage and health status, focus on whole-food sources of tryptophan (e.g., turkey, eggs, seeds) rather than high-dose supplements for appetite control.

LimitedQualifiesLOW confidence
gut microbiota participates in the 5-HT production and influences the serotonergic neuronal networks... indole and its derivate... produced by Edwardsiella tarda, form Trp that can bind with transient receptor potential ankyrin Aa (Trpa1) to enhance 5-HT secretion from enteroendocrine cells
Hui Han et al. · Microbiome · 2021

Why this rating

The paper highlights inconsistent and contradictory results regarding Trp supplementation and appetite.

Source

From gut microbiota to host appetite: gut microbiota-derived metabolites as key regulators

Hui Han et al. · Microbiome · 2021

DOI 10.1186/s40168-021-01093-y

narrative_reviewCited 285×
Read the paper
DOI resolved against Crossref · corpus check 2026-06-10

This is one finding among thousands. Every one is graded and traced to its source, so you can see what the evidence actually supports. Browse the research →