Oolong tea polyphenols alleviate cognitive impairment in sleep-deprived mice through the microbiota–gut–brain axis

Sleep deprivation (SD) is a prevalent health risk factor in modern society. It can lead to gut microbiota dysbiosis and related cognitive impairment, so natural intervention strategies targeting the microbiota-gut-brain axis have significant research significance. As the main active components in oolong tea, Oolong Tea Polyphenols (OTPs) possess neuroprotective potential and gut microbiota-regulating potential. However, their role and mechanism in cognitive impairment induced by SD remain unclear. In this study, a mouse model of sleep deprivation was established using the modified multiple platform water environment method. Through techniques including behavioral experiments, 16S rRNA sequencing and other methods, the intrinsic mechanism by which OTPs ameliorate cognitive impairment induced by sleep deprivation was systematically evaluated. The results showed that OTP supplementation significantly improved various behavioral indicators of sleep-deprived mice, reversed the dysbiosis of the microbiota structure, increased the abundance of beneficial bacteria such as <i>Lactobacillus</i>, reduced the abundance of harmful bacteria such as <i>Desulfovibrio</i> and thus promoted the production of short-chain fatty acids. Meanwhile, OTPs improved intestinal barrier function, reduced the levels of serum lipopolysaccharide and inflammatory factors, protected the integrity of the blood-brain barrier (BBB), inhibited the excessive activation of neuroglial cells in the hippocampal region, downregulated the activity of the TLR4/NF-κB signaling pathway and restored the balance of neurotransmitters in the hippocampus. In conclusion, OTPs significantly alleviate SD-induced cognitive impairment <i>via</i> the microbiota-gut-brain axis, which provides a theoretical basis for their application as a food-derived intervention strategy.