BackgroundQiweibaizhu powder (QWBZP) has been shown to be effective in treating antibiotic-associated diarrhea (AAD). Previous research has reported that plant polysaccharides can promote the growth of beneficial intestinal bacteria and inhibit the multiplication of pathogenic bacteria, thus effectively treating diarrhea. Here, we investigated the effect of QWBZP crude polysaccharide on the diversity of intestinal mucosal bacteria and their community structure composition in mice with AAD, and the aim of this study was to provide the scientific basis for the efficacy of QWBZP crude polysaccharide on diarrhea.Materials and MethodsEighteen Kunming (KM) mice were randomly divided into the normal (mn) group, the model (mm) group, and the QWBZP crude polysaccharide treatment (ma) group, with six mice in each group. An AAD model was constructed using a mixed antibiotic solution and treated with gavage crude polysaccharide solution of QWBZP. The intestinal mucosa was extracted from the jejunum to the ileum of mice, and the metagenome was extracted and then analyzed using MiSeq sequencing to characterize the intestinal mucosal bacteria in mice.ResultsThe spleen and thymus indices of each group of mice had no significant differences. The Chao1 and ACE indices of the mn and mm groups were similar, the Simpson index was the largest and the Shannon index was the smallest in the mm group, and there was no significant difference in the diversity indices of all three groups. In the PCA and PCoA, the mn and ma group samples were both relatively concentrated with a high similarity of community structure. In contrast, the samples in the mm group were more scattered and farther away from the samples in the mn and ma groups, i.e., the community structure similarity within and between the groups was low. Compared with the mm group, the relative abundance of Proteobacteria, Lactobacillus, and the Firmicutes/Bacteroidetes (F/B) ratio in the ma group was decreased, while that of Enterococcus continued to increase. In the LEfSe analysis, there were significant differences in the characteristic bacteria in the mn, mm, and ma groups.ConclusionThe single crude polysaccharide component is not very effective in treating AAD, so the clinical efficacy of the QWBZP crude polysaccharide is subject to further investigation.

To probe into the mechanism of antibiotic-associated diarrhea (AAD), the bacterial diversity and composition in the intestinal mucosa of AAD mice were investigated. Twelve specific pathogen-free Kunming mice were divided into control group and model group. The mouse model of AAD was established by gavaging with antibiotics (mixture of gentamycin sulfate and cefradine) at a total dose of 23.33 ml kg −1 day −1 for 5 days continuously, twice a day. The mice in the control group were given with an equal amount of sterile water. Then, the intestinal mucosa DNA was extracted for 16S rRNA gene sequence analysis by high-throughput sequencing. The results showed that the alpha diversity of the two groups did not differ significantly from each other, while the composition of intestinal mucosa bacteria differed dramatically between the two groups. The model group showed a higher abundance of Proteobacteria and Actinobacteria. More importantly, Lactobacillus was significantly less abundant (p = 0.000), while Enterococcus was significantly more abundant (p = 0.019) in the model group than in the control group. Furthermore, antibiotic treatment increased the abundance of Citrobacter, Stenotrophomonas, and Glutamicibacter,whereas antibiotics decreased the abundance of Mycoplasma and Helicobacter. In addition, 6 and 11 unique genera were found in the control group and model group, respectively. The combination of gentamycin sulfate and cefradine changed the intestinal mucosa bacterial composition, reduced colonization resistance and damaged the intestinal mucosal barrier by reducing the abundance of Lactobacillus.

A growing body of evidence suggests that the disturbance of intestinal microbiota induced by high-fat diet is the main factor causing many diseases. Dendrobium officinale (DO), a medicinal and edible homologous Chinese herbal medicine, plays essential role in regulating intestinal microbiota. However, the extent of DO on the intestinal contents microbiota in mice fed with a high-fat diet still remains unclear. Therefore, this study explored the role of intestinal contents microbiota in the regulation of adverse effects caused by high-fat diet by DO from the perspective of intestinal microecology. Twenty-four mice were randomly distributed into the normal saline-treated basal diet (bcn), normal saline-treated high-fat diet (bmn), 2.37 g kg−1 days−1 DO traditional decoction-treated high-fat diet (bdn) and 1.19 g kg−1 days−1 lipid-lowering decoction-treated high-fat diet (bjn) groups for 40 days. Subsequently, we assessed the changes in body weight, serum total cholesterol (TC), total triacylglycerol (TG), low density lipoprotein-cholesterol (LDL-C), high density lipoprotein-cholesterol (HDL-C) levels, and the characteristics of intestinal contents microbiota. Results demonstrated that DO exerted the modulating effect on the changes in body weight, TG, TC, LDL-C, and HDL-C levels. Besides, DO decreased the richness and diversity of intestinal contents microbiota, and altered the structure as a whole. Dominant bacteria, Ruminococcus and Oscillospira, varied significantly and statistically. Moreover, DO influenced the carbohydrate, amino acid, and energy metabolic functions. Furthermore, Ruminococcus and Oscillospira presented varying degrees of inhibition/promotion of TG, TC, LDL-C, and HDL-C. Consequently, we hypothesized that Ruminococcus and Oscillospira, as dominant bacteria, played key roles in the treatment of diseases associated with a high-fat diet DO.

Background: Extensive evidence suggests that gut microbiota may interact with the kidneys and play central roles in the pathogenesis of disease. However, the association of gut microbiota-kidneys in diarrhea remains unclear. Methods: A diarrhea mouse model was constructed by combining adenine with Folium sennae. We analyzed the characteristics of the gut content microbiota and short chain fatty acids (SCFAs); and explored the potential link between gut content microbiota, SCFAs, intestinal inflammatory response and kidney function. Results: Characteristic bacteria Lactobacillus intestinalis and Bacteroides acidifaciens were enriched in the gut contents of mice. The productions of SCFAs were remarkably inhibited. Model mice presented an increased trend of creatinine (Cr), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α), a decreased trend of blood urea nitrogen (BUN) and secretory immunoglobulin A (SIgA). The pathological analysis proved obvious damage to the kidney structure. Lactobacillus intestinalis and Bacteroides acidifaciens exisited in the correlations with acetic acid, intestinal inflammatory response and kidney function. Conclusions: Adenine combined with Folium sennae-induced diarrhea, altered the structure and function of the gut content microbiota in mice, causing the enrichment of the characteristic bacteria Lactobacillus intestinalis and Bacteroides acidifaciens. The interactions between Lactobacillus intestinalis, Bacteroides acidifaciens and acetic acid, intestinal inflammation, and kidney function might be involved in the process of gut-kidney impairment in adenine, combined with Folium sennae-induced diarrhea.

AimThe current study aimed to investigate the effects of Debaryomyces hansenii on the diversity of bacterial lactase gene in the intestinal mucosa of antibiotic-associated diarrhea (AAD) mice.MethodsEighteen mice were randomly divided into three groups (6 mice per group): healthy control group, diarrhea model group and D. hansenii treatment group. The antibiotic-associated diarrhea model was established by intragastric administration with a mixture of cephradine and gentamicin sulfate (23.33 mL·kg-1·d-1) twice a day for 5 days continuously. After establishing the AAD model, the mice in the D. hansenii treatment group were gavaged with D. hansenii for three days, while other groups were gavaged with distilled water. Then, the intestinal mucosa of all three groups was collected and DNA was extracted in an aseptic environment for the following analysis.ResultsThe difference in the richness and homogeneity of the bacterial lactase gene among all samples were inapparent, as the difference in the Chao1, ACE, Simpson and Shannon indices among the three groups were insignificant (P>0.05). NMDS analysis also showed that the distance of the samples among the three groups was unobvious. Furthermore, the bacterial lactase gene in the mucosa mainly originated from Actinobacteria, Firmicutes and Proteobacteria. Compared with the healthy control group, the abundance of lactase genes originating from Cupriavidus, Lysobacter, Citrobacter, Enterobacter and Pseudomonas was increased in the D. hansenii treatment group, while the lactase gene from Acidovorax and Stenotrophomonas decreased (p < 0.01 or p < 0.05) in the diarrhea model group and the D. hansenii treatment group.ConclusionD. hansenii was capable of improving the growth of some key lactase-producing bacteria like Deinococcus, Cupriavidus and Lysobacter for treating AAD.