Type 2 diabetes mellitus (T2DM) is an important public health problem. The knowledge of bacterial communities in the gut of Vietnamese patients with T2DM and non diabetic controls is still insufficient. We report in this article the 16S rDNA amplicon data of the gut microbiomes of Vietnamese patients with T2DM and nondiabetic controls carried out using the Illumina sequencing. This work included 7 patients and 7 controls. A total of 1,627,646 reads were obtained and a total of 13 phyla, 25 classes, 94 genera were revealed. The top three dominant bacterial phyla in all subjects were Firmicutes, Bacteroidetes and Proteobacteria. Significant differences in the relative abundances of the phylum Firmicutes and class Clostridia between patients and controls were observed, suggesting that the reducing of phylum Firmicutes and class Clostridia in the gut may be linked to obesity and T2DM. All sequencing libraries were deposited in the NCBI SRA as BioProject PRJNA668251. The datasets are needed to determine the association between the bacterial composition of the gut and the pathogenesis of T2DM in Vietnamese patients.