Modulating stress responses via the microbiota-gut-brain axis: a pathway-focused review of GABA, 5-HT, and kynurenine metabolites - Xiaole Zhao; Shensheng Xiao; Xiaoming Ma; Yan Qi; Zhaonan Liu; Xinrui Xu; Chao Chang; Jine Wu; Zhiyong Gong; Bing Shao; Xin Liu (Food Research International, 2026)