The 5-HTP market was valued at USD 31.7 million in 2012 and is anticipated to reach USD 51.4 million by 2019, increasing at a CAGR of 7.1%. The present invention provides a valuable alternate to the plant extraction for the production of 5-HTP. The genetically modified yeast strain will provide sustainable and reliable suppy of 5-HTP. Using this invention, the yeast strains that produce 5-HTP could be developed as the dietary supplement for farm animals (e.g., cows and chickens), and increase the value of farm products. The probiotic yeast strains could also be developed as the pet food to improve the health of pets (e.g., cats and dogs). It is also possible that the probiotic yeast strains could be directly developed as the dietary supplement for improving human health (e.g., improving the resistance to depression).