A Comparison Between Normal and Reddened Mung Bean Soup: Beneficial Effects on the Regulation of Oxidative Stress, Inflammation, and Gut Microbiota in Mice with Heat Stress-Induced Damages.

BACKGROUND

Mung bean soup (MBS), as a common form of mung bean consumption, is widely consumed in folk to relieve summer heat. However, MBS is prone to red discoloration during cooking and storage. Furthermore, how this color change affects its phenolic compounds composition and bioactivity remains poorly understood.

OBJECTIVES

Herein, this study systematically compared the phenolic profiles and heat stress (HS)-alleviating effects of normal mung bean soup (NMBS) and reddened mung bean soup (RMBS).

METHODS

Male C57BL/6J mice (six-week-old) were randomly assigned to four groups: control (no HS), HS, HS-NMBS, and HS-RMBS. HS was induced at 40 °C for 2 h/day for 7 days, with NMBS or RMBS provided ad libitum throughout the experiment. Phenolic analysis, oxidative stress markers, inflammatory cytokines, and gut microbiota were evaluated.

RESULTS

The results showed that reddening significantly reduced the total phenolic and flavonoid contents by 18.28% and 16.77%, respectively, accompanied by the loss of key bioactive compounds (vitexin and isovitexin). NMBS and RMBS could effectively alleviate HS-induced physiological damages in mice to varying degrees, including reduced weight loss, improved hepatic and intestinal histopathology, and lower levels of oxidative stress and inflammation (p < 0.05). However, NMBS provided superior overall protection by downregulating the expression of HS-associated genes (PPAR-γ) and pro-inflammatory cytokines (IL-1β), while upregulating the anti-inflammatory cytokine IL-10. Furthermore, supplementation with NMBS or RMBS restored the gut microbiota dysbiosis induced by HS. Especially, NMBS was more effective in restoring microbial diversity, modulating the F/B ratio, and enriching beneficial bacteria including Lactobacillus, Dubosiella, and norank_f_Muribaculaceae.

CONCLUSIONS

These results highlight the importance of avoiding the occurrence of redness in MBS to maximize its efficacy.