Tryptophan metabolic pathway plays a key role in the stress-induced emotional eating

Ying Zhu; Lifeng Yin; Qing Liu; Yaoxing Guan; Shuang Nie; Yongheng Zhu; Fengfeng Mo

doi:10.1016/j.crfs.2024.100754

Tryptophan metabolic pathway plays a key role in the stress-induced emotional eating

Curr Res Food Sci. 2024 Apr 26:8:100754. doi: 10.1016/j.crfs.2024.100754. eCollection 2024.

Authors

Ying Zhu^{1

2}, Lifeng Yin^{1

2}, Qing Liu^{2

3}, Yaoxing Guan^{1

2}, Shuang Nie^{2

3}, Yongheng Zhu¹, Fengfeng Mo^{2

3}

Affiliations

¹ College of Food Science and Technology, Shanghai Ocean University, Shanghai 201306, China.
² Department of Naval Nutrition and Food Hygiene, Naval Medical University, Shanghai 200433, China.
³ Shanghai Key Laboratory of Nautical Medicine and Translation of Drugs and Medical Devices, The First Affiliated Hospital of Naval Medical University, Shanghai 200433, China.

Abstract

Chronic stress disrupts the emotional and energetic balance, which may lead to abnormal behaviors such as binge eating. This overeating behavior alleviating the negative emotions is called emotional eating, which may exacerbate emotional instability and lead to obesity. It is a complex and multifaceted process that has not yet been fully understood. In this study, we constructed an animal model of chronic mild stress (CMS)-induced emotional eating. The emotional eating mice were treated with tryptophan for 21 days to reveal the key role of tryptophan. Furthermore, serum-targeted metabolomics, immunohistochemical staining, qPCR and ELISA were performed. The results showed that CMS led to the binge eating behavior, accompanied by the disturbed intestinal tryptophan-derived serotonin (5-hydroxytryptamine; 5-HT) metabolic pathways. Then we found that tryptophan supplementation improved depression and anxiety-like behaviors as well as abnormal eating behaviors. Tryptophan supplementation improved the abnormal expression of appetite regulators (e.g., AgRP, OX1R, MC4R), and tryptophan supplementation also increased the tryptophan hydroxylase 2 (tph2) and 5-HT receptors in the hypothalamus of CMS mice, which indicates that the 5-HT metabolic pathway influences feeding behavior. In vitro experiments confirmed that 5-HT supplementation ameliorated corticosterone-induced aberrant expression of appetite regulators, such as AgRP and OX1R, in the hypothalamic cell line. In conclusion, our findings revealed that the tryptophan-derived 5-HT pathway plays an important role in emotional eating, especially in providing targeted therapy for stress-induced obesity.

Keywords: 5-HT; Appetite; Chronic stress; Depression; Emotional eating; Tryptophan.