Changes in Diversity of Intestinal Butyrate-producing Bacteria During Treatment with Shenling Baizhusan and Lizhongtang in Animal Model of AAD / 中国实验方剂学杂志

Objective:To explore the microecological mechanisms of Shenling Baizhusan （SLBZ） and Lizhongtang （LZ） in treating antibiotic-associated diarrhea （AAD） based on changes in the diversity of intestinal butyrate-producing bacteria. Method:SD rats were randomly divided into an SLBZ group （5.5 g·kg^-1·d^-1） and an LZ group （5.5 g·kg^-1·d^-1）. The gut microbiota disturbance model was induced by intragastric administration of clindamycin hydrochloride （315 mg·kg^-1·d^-1） and AAD model by <italic>Clostridium difficile</italic>. Subsequently， the rats were treated correspondingly. Fecal samples at different stages were collected and the total DNA was extracted. Polymerase chain reaction （PCR） amplification was performed with the primers of butyryl coenzyme A （CoA）-CoA transferase genes. The PCR products were cloned and sequenced to analyze the diversity response of butyrate-producing bacteria. Result:After treatment， both groups showed increased food uptake， formed feces， glossy and smooth fur， and improved activity and sensitivity. With the butyryl CoA-CoA transferase gene as the molecular marker， 297 sequences of butyrate-producing bacteria in the SLBZ group （SPD for short） and 300 sequences of butyrate-producing bacteria in the LZ group （LPD for short） were obtained. In the SLBZ group， 98， 100， and 99 sequences of SPD were obtained at the normal stage， the modeling stage， and the treatment stage， respectively， belonging to 8， 3， and 6 operational taxonomic units （OTUs）， with similarity ranges of 78%-97%， 86%-99% ， and 81%-97%. The number of OTUs recovered to 75% of the normal level after treatment. In the LZ group， 100 sequences of LPD were obtained at the normal stage， the modeling stage， and the treatment stage， respectively， belonging to 6， 2， and 4 OTUs， with similarity ranges of 83%-97%， 92%-99%， and 85%-99%. The number of OTUs recovered to 80% of the normal level after treatment. Butyrate-producing bacteria were present in all stages of the two groups， dominated by Firmicutes， accounting for more than 98% of the total number. The effects of SLBZ on SPD at the genus level were observed in the significant decrease in <italic>Clostridium</italic> abundance and the significant increase in <italic>Eubacterium</italic> abundance. The effect of LZ on LPD was mainly concentrated on the <italic>Roseburia </italic>at the genus level， and LZ also increased the abundance of <italic>Eubacterium</italic>， <italic>Lacrimi</italic>sp<italic>ora</italic>， and <italic>Clostridium</italic>. According to the phylogenetic tree， the classification of butyrate-producing bacteria increased from five clusters to seven clusters after SLBZ treatment， while that increased from three clusters to nine clusters after LZ treatment. Conclusion:In the treatment of AAD， SLBZ and LZ can regulate the structure and abundance of butyrate-producing bacteria in the intestine， restore their diversity， and improve the instability of the intestinal microecological environment.