Gut microbes play an important role in maintaining human health and inducing disease development. The glycosylation modification of gut microbes has a profound impact on the host’s life activities. From the perspective of glycomics, this review discusses and analyzes the composition and function of gut microbes, the glycosylation patterns of representative bacteria and their closely related physiological functions. We aslo summarize the regulation ways of glycosylation on gut microbial functions and activities.