Taurine attenuates heat stress-induced intestinal permeability by inhibiting endoplasmic reticulum stress and modulating gut microbiota.

Chronic heat stress (HS) impairs intestinal barrier function and microbiota homeostasis. Taurine, a functional amino acid, is well characterized by anti-oxidation, anti-inflammation and cytoprotection. However, whether taurine can maintain intestinal barrier integrity and microbiota under chronic HS remains unknown. Mice (6-week-old; C57BL/6; Male) were randomly assigned one of three groups including a control group (CON, 23°C), a heat stress group (HS, 42°C), or a heat stress + taurine group (HT, received 0.5% taurine in drinking water under HS condition). This study investigated the effects of taurine supplementation on intestinal morphology, barrier function, endoplasmic reticulum stress (ERS), apoptosis, and gut microbiota in heat-stressed mice. Taurine supplementation contributed to decreased rectal temperature and body weight loss in heat-stressed mice. Taurine improved intestinal morphology as demonstrated by elevated villus height in HT group compared to HS group. HS-induced intestinal permeability indicative of increased d-lactate was inhibited by upregulating ZO-1 expression in mice administrated by Taurine. Supplementary taurine normalized the expression of endoplasmic reticulum (ER) stress proteins (BIP, IRE1α, XBP-1, CHOP) as well as proapoptotic proteins (BAX, Cytc, and Active-caspase 3) in HT mice. Taurine intervention resulted in expansion of taurine-utilizing Desulfovibrio in HT mice. Moreover, taurine supplementation enhanced enrichment of SCFA-producing microbiota such as Bifidobacterium, Dubosiella, and Faecalibaculum in heat-stressed mice. Collectively, these results suggested that taurine could attenuate HS-induced intestinal barrier dysfunction via reversing ER stress-mediated apoptosis and gut microbial dysbiosis, suggesting taurine as a promising dietary additive against the intestinal injury induced by HS in mice.