Diarrhea is a global disease with a high morbidity and mortality rate in children. In this study, 25 fecal samples were collected from children under 5 years old. Seven samples had been taken from healthy children without diarrhea and marked as the healthy control group; eight samples had been sampled from children with diarrhea caused by dyspepsia and defined as the non-infectious group; and ten samples had been taken from children with diarrhea induced by intestinal infections and identified as the infectious group. We detected the microbial communities of samples by using high-throughput sequencing of 16S rRNA genes. The proportion of aerobic and facultative anaerobic microbes in samples of the infectious group was much higher than in the non-infectious group. In addition, the relative abundance of Enterococcus in the healthy control group was significantly higher than in the non-infectious group and infectious group. This can be used as a potential diagnostic biomarker for diarrhea.