TPH1 and Anxiety: In conclusion, our result showed that ingesting β-lactoglobulin Trp peptide affects anxiety behaviors and 5-HT levels of zebrafish. The potential anti-anxiety functions of β-lactoglobulin Trp peptide may be associated with increasing TPH activity and enhancing 5-HT synthesis, with the Val-Ala-Gly-Thr-Trp being more effective.