BACKGROUND: Qiweibaizhu powder (QWBZP) is a classical prescription of traditional Chinese medicine (TCM) to treat diarrhea in pediatric patients. Its use in health care practices and interventions has shown its effect on antibiotic-associated diarrhea (AAD). It is known that the occurrence of AAD is related to an imbalance of intestinal micro-ecology. Previous studies found that QWBZP could regulate the amount of some cultured microbes and the activities of lactase and sucrase in AAD mice. In order to investigate the treatment mechanism of QWBZP on AAD, we studied the effect of QWBZP on intestinal bacteria in a community of AAD mice.

MATERIAL AND METHODS: AAD mice were established by administrating the mixture of gentamycin sulfate and cefradine at the dose of 23.33 mL·kg⁻¹·d⁻¹ for 5 days. Then the AAD mice were gavaged with QWBZP decoction for 4 days and gradually recovered to a normal status. On the tenth day, the intestinal contents of mice were collected, and then the DNA was extracted for 16S rRNA sequencing followed by analysis.

RESULTS: The analysis of bacterial 16S rRNA sequencing showed the Simpson index was decreased and the Shannon index was increased in AAD mice treated with QWBZP compared to the model group; there was no significant difference between the control group and the treatment group (P>0.05). Principle co-ordinates analysis (PCoA) indicated that there was a shorter distance between the control group and the treatment group than that between the control group and model group. At the phylum level, use of antibiotics decreased the relative abundance of Actinobacteria, Bacteroidetes, and Proteobacteria, but increased the abundance of Firmicutes and Verrucomicrobia, and the reverse changes occurred after treated with QWBZP. At the genus level, the abundance of Bacteroides and Ochrobacitrum increased in the model group, while an opposite result was observed in the treatment group. Moreover, the relative abundance of Osillospira decreased in the model group and increased in the treatment group. Genus Dorea, Coprococcus and Blautia in the model group were higher than those in the control group and further increased in the treatment group.

CONCLUSIONS: These results indicated that QWBZP improved the diarrhea syndrome with restoring the diversity and adjusting the structures of bacteria in mice intestine, which might reveal the therapeutic mechanism of QWBZP on treating AAD.

Keywords: Bacteria, diarrhea, Enterocolitis, Pseudomembranous, Qiweibaizhu Powder, Anti-Bacterial Agents, Gastrointestinal Contents, Intestines, Powders