Nocturnal hyperglycemia is a critical yet poorly controlled risk factor for complications in type 2 diabetes mellitus (T2DM), highlighting an unmet clinical need. The gut microbiota, a key regulator of host metabolism and circadian rhythms, has emerged as a pivotal player in this process, offering a novel therapeutic target. This article elaborates on the relationship between gut microbiota and nocturnal blood glucose control in T2DM from four key dimensions: the core gut microbiota-circadian cl