OBJECTIVE: To study the intervention effects of Lizhong decoction on antibiotic-associated diarrhea（AAD）

and to reveal the modulation of gut microbiota during the alleviation of AAD.METHODS: AAD rat model was established

and Bifidobacterium triple viable capsules were used as the positive control（Bif

70 mg/d）. Lizhong decoction was administered at 3.75 g/kg and 7.5 g/kg（measured as the quantity of crude material）. The general condition of the rats was observed

and the diarrhea degree of the rats was evaluated by 120 min fecal weight

fecal water content and fecal score. Colon tissues for histopathological examination were stained with hematoxylin and eosin（HE） staining

and 16 S rRNA sequencing analysis of gut microbiota was performed. RESULTS: After administration of Bif

the degree of diarrhea in rats was alleviated. The fecal water content

fecal score and 120 min fecal weight of rats in the high-and low-dose Lizhong decoction groups showed significant improvements

with the low-dose group being slightly more effective than the high-dose group. Results of HE staining of rat colon tissue showed that the treatment of high-and low-dose Lizhong decoction could improve the pathological changes such as colon inflammation in rats. Results of gut microbiota analysis showed that after the intervention of Bif and Lizhong decoction

the abundance and diversity of gut microbiota in AAD rats were slightly improved

and there was no significant difference between them（P>0.1）. However

compared with the AAD model group

Lizhong decoction significantly restored the abundance of Firmicutes at the phylum level（P<0.05）

Klebsiella spp. at the genus level（P<0.05） and Parasutterella spp. at the genus level（P<0.05）

the differences were statistically significant. Lizhong decoction restored the Bacteroides spp. at the genus level

yet the difference was not statistically significant compared with the AAD model group（0.05MoreReset