Dose of sucrose affects the efficacy of Qiweibaizhu powder on antibiotic-associated diarrhea: Association with intestinal mucosal microbiota, short-chain fatty acids, IL-17, and MUC2

Introduction

Due to the poor taste of Qiweibaizhu powder (QWBZP), patients have difficulty taking medicine, which leads to poor compliance and limits clinical use to a certain extent. In the trend of restricting sugar intake, sweeteners have gained massive popularity, among which sucrose is a commonly used sweetener in preparations. This study aimed to investigate the effect of different sucrose dose addition with antibiotic-associated diarrhea (AAD) by intervened QWBZP on intestinal mucosal microbiota.

Methods

Thirty specific-pathogen-free (SPF) Kunming (KM) male mice were randomly divided into normal group (N), natural recovery group (M), QWBZP group (Q), low dose sucrose group (LQ), medium dose sucrose group (MQ), and high dose sucrose group (HQ). Subsequently, 16S rRNA amplicon sequencing and GC-MS techniques were used to analyze the intestinal mucosal microbiota and short-chain fatty acid (SCFAs) in intestinal contents, respectively, and enzyme-linked immunosorbent assay was used to determine mucin 2 (MUC2) and interleukin 17 (IL-17).

Results

Compared with the Q group, the results showed that with the increase of sucrose dose, the intestinal microbial structure of mice was significantly altered, and the intestinal microbial diversity was elevated, with the poor restoration of the intestinal biological barrier, decreased content of SCFAs, high expression of inflammatory factor IL-17 and decreased content of mucosal protective factor MUC2. In conclusion, we found that the addition of sucrose had an effect on the efficacy of the AAD intervented by QWBZP, which was less effective than QWBZP, showing a certain dose-response relationship. In this experiment, it was concluded that the addition of sucrose might also further lead to intestinal inflammation and the disruption of the intestinal mucosal barrier, and the production of metabolites SCFAs.

Discussion

The addition of sucrose might also further lead to intestinal inflammation and the disruption of the intestinal mucosal barrier, and the production of metabolites SCFAs. However, these findings still need to be verified in a more extensive study. The effect of adding the sweetener sucrose on the efficacy of Chinese herbal medicine in treating diseases also still needs more research.

Intestinal mucosal bacterial diversity of antibiotic-associated diarrhea (AAD) mice treated with Debaryomyces hansenii and Qiweibaizhu powder

The aim was to investigate the combined effect of Debaryomyces hansenii and Qiweibaizhu powder (QWBZP) on the bacterial diversity of the intestinal mucosa of antibiotic-associated diarrhea (AAD) mice, for the potential treatment of diarrhea, especially which is induced by administration of antibiotics. Eighteen (18) mice were randomly assigned to three equal groups of six mice, namely Normal (mn group), Placebo control (mm group) and D. hansenii and QWBZP (DQ) treatment (mdq group). Mice were gavaged with a solution (23.33 mL·kg^-1·day^-1) consisting of gentamicin and cefradine to establish AAD. The DQ treatment group was gavaged with DQ for 4 days, and sterile water was used as a placebo control. The metagenome DNA of the intestinal mucosal microbiota was extracted, and the 16S rRNA gene was sequenced. Analysis showed that there were 288 OTUs for the normal group, 443 for the placebo control group, and 229 for the DQ treatment group. Phylogenetically, the gut microbiota of the DQ treatment group and the normal group were closer to each other than to the placebo control group. Both the DQ and placebo-treated groups included Stenotrophomonas, Robinsoniella, Bacteroidales S24-7 group norank, Citrobacter, and Glutamicibacter, but their abundances were significantly higher in the DQ treatment group than in the placebo control group. This suggested that the combined use of D. hansenii and QWBZP overcame the influence of dysbacteriosis and could lead to the recovery of intestinal mucosal microbiota homeostasis. This positive effect is likely related to short-chain fatty acid (SCFA)-producing bacteria, such as members of Micrococcaceae, Lachnospiraceae, and Bacteroidales S24-7 group, which could play beneficial roles in protecting the mucosal barrier and stimulating the immune response in mice.

Effect of Debaryomyces hansenii combined with Qiweibaizhu powder extract on the gut microbiota of antibiotic-treated mice with diarrhea

The aim of this study was to investigate the effects of an extract of Qiweibaizhu powder combined with Debaryomyces hansenii on the gut microbiota of antibiotic-treated mice with diarrhea. Mice were gavaged with a mixture of gentamycin sulfate and cefradine to induce diarrhea. After diarrhea was observed, 25% dose of ultra-micro Qiweibaizhu powder extract combined with 25% dose of Debaryomyces hansenii (QCD) was gavaged to mice with diarrhea. DNA of intestinal contents in mice was extracted for 16S rRNA gene sequence analysis by high-throughput sequencing following treatment finished. The results showed that the QCD increased the species richness and diversity, but did not recover the diversity to the original level. Antibiotics and QCD significantly altered the composition of gut microbiota at different taxonomic levels. At the genus level, the relative abundance of Bacteroidales S24-7 group_unidentified and Bacteroides returned to baseline after QCD treatment. Additionally, QCD suppressed the growth of Oscillospira and Ruminococcus, and promoted the proliferation of Erysipelotrichaceae_norank and Blautia compared with the healthy and diarrheal mice. Our results indicated that QCD modulated the diversity and composition of the gut microbiota in antibiotic-treated mice with diarrhea. The synergistic effect between Qiweibaizhu powder extract and Debaryomyces hansenii may be related to Bifidobacterium and Bacteroidales S24-7 group_unidentified.

Bacterial lactase genes diversity in intestinal mucosa of dysbacterial diarrhea mice treated with Qiweibaizhu powder

The current research tried to investigate the effect of Qiweibaizhu powder (QWBZP) on intestinal mucosa bacterial lactase gene from dysbacterial diarrhea mice, as the good therapeutic mechanism of QWBZP on antibiotics-induced diarrhea. Dysbacterial diarrhea mice model was constructed by gastric perfusion with mixture of cephradine capsules and gentamicin sulfate (23.33 mL kg-1 day-1) for 5 days. After the success of establishing diarrhea, the mice in treatment group were gavaged with QWBZP for 3 days. Intestinal mucosa in each group was collected, and diversity of bacterial lactase genes in intestinal mucosa of mice was carried out by Miseq metagenome sequencing. The results showed the Chao1, ACE, Simpson and Shannon indices in treatment group were lower than model group and were similar to control group. The same result was obtained from the operational taxonomic units (OTUs). There were 298, 435 and 254 OTUs in the control group, model group and treatment group, respectively. Principal component analysis (PCA) indicated that samples distribution in both normal and treatment groups were relatively intensive, distances among individuals were small, while opposite results were observed in model group. Moreover, antibiotics increased the diversity and abundance of bacterial lactase genes at phylum and genus levels. However, they decreased and were similar to control group after treating with QWBZP. Our results indicate that QWBZP has a positive effect on the recovery of bacterial lactase gene diversity to normal level. In addition, QWBZP increase the abundance of Lysobacter and Eukaryota.