Toxicity evaluation of processing Evodiae fructus based on intestinal microbiota.

Background: With the development of healthcare services, drug efficacy, and safety have become the focus of drug use, and processing alters drug toxicity and efficacy, exploring the effects of processing on Evodiae fructus (EF) can guide the clinical use of drugs. Methods: Fifty male Kunming mice were randomly divided into the control group (CCN), raw small-flowered EF group (CRSEF), raw medium-flowered EF group (CRMEF), processing small-flowered EF group (CPSEF), and processing medium-flowered EF group (CPMEF). The CRSEF, CRMEF, CPSEF, and CPMEF groups were gavaged with aqueous extracts of raw small-flowered EF dry paste (RSEF), medium-flowered EF dry paste (RMEF), processing small-flowered EF dry paste (PSEF) and processing medium-flowered EF dry paste (PMEF), respectively, for 21 days at 5 times the pharmacopeial dosage. Upon concluding the experiment, histopathological sections of liver and kidney tissues were examined. Additionally, levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), serum creatinine (SCr), and blood urea nitrogen (BUN) were determined. DNA from the intestinal contents of the mice was extracted, and 16S rRNA full-length high-throughput sequencing was performed. Results: After fed EF 21 days, mice exhibited a decreasing trend in body weight. Comparative analysis with the CCN group revealed an upward trend in SCr, BUN, AST, and ALT levels in both CRSEF and CRMEF groups. The CRMEF group displayed notably elevated BUN and AST levels, with an observed increasing trend in Scr and ALT. Kidney sections unveiled cellular edema and considerable inflammatory cell infiltrates, whereas significant liver damage was not evident. Compared with CRSEF, Bun levels were significantly lower while AST levels were significantly higher in the CPMEF group. Additionally, the intestinal microbiota diversity and the relative abundance of Psychrobacter decreased significantly, and the relative abundance of Staphylococcus, Jeotgalicoccus, and Salinicoccus increased significantly in the CPMEF group. AST, ALT, and SCr were positively correlated with Staphylococcus, Jeotgalicoccus, and Salinicoccus. Conclusion: In conclusion, PMEF significantly increased harmful bacteria (Staphylococcus, Jeotgalicoccus, and Salinicoccu) and decreased beneficial bacteria. SEF with 5 times the clinical dose showed nephrotoxicity and SEF nephrotoxicity decreased after processing, but EF hepatotoxicity was not significant, which may be due to insufficient dose concentration and time.

Baohe pill decoction treats diarrhea induced by high-fat and high-protein diet by regulating lactase-producing bacteria in intestinal mucosa.

Introduction: This study aimed to investigate the effects of Baohe pill decoction (BPD) on microbial, lactase activity, and lactase-producing bacteria in the intestinal mucosa of mice with diarrhea induced by high-fat and high-protein diet (HFHPD). Methods: Thirty male Kunming (KM) mice were randomly divided into normal (NM), model (MD), and BPD groups. Diarrhea models were manufactured using HFHPD combined with a gavage of vegetable oil. At the end of modeling, the BPD group was given BPD (6.63 g·kg-1d-1) intervention twice daily for 3 d. The NM and MD groups were given equal amounts of sterile water. Subsequently, the intestinal mucosa of the mice was collected, one portion was used for microbial and lactase activity measurement, and the other portion was used for its lactase-producing bacterial characteristics by high-throughput sequencing technology. Results: Our results showed that microbial and lactase activity of intestinal mucosa decreased significantly following diarrhea in mice (Pmicrobial < 0.05, Plactase < 0.001). After BPD intervention, microbial and lactase activity increased significantly (P < 0.01). The number of operational taxonomic units (OTUs), richness, and diversity index of lactase-producing bacteria increased in the BPD group compared to the MD group (P > 0.05), and the community structure were significant differences (P < 0.01). Compared to other groups, Saccharopolyspora, Rhizobium, Cedecea, and Escherichia were enriched in the BPD group. Notably, the relative abundance of the dominant lactase-producing genus Bifidobacterium decreased after BPD intervention. Discussion: The mechanism of BPD in relieving diarrhea induced by HFHPD is closely related to the promotion of lactase activity in the intestinal mucosa, which may be achieved by regulating the structure of lactase-producing bacteria.

Diarrhea Caused by High-Fat and High-Protein Diet Was Associated With Intestinal Lactase-Producing Bacteria.

BACKGROUND/AIMS: This study aimed to investigate the effect of diarrhea induced by a high-fat and high-protein diet on lactase-producing bacteria in the intestinal contents of mice from the perspective of diarrhea-related genes. MATERIALS AND METHODS: Ten specific pathogen-free Kunming male mice were chosen and randomly divided into the normal group and model group. The mice in the normal group were fed with high-fat and high-protein diet plus gavage of vegetable oil, while those in the model group were fed with general diet plus gavage of distilled water. After successful modeling, the distribution and diversity of lactase-producing bacteria in the intestinal contents were characterized by metagenomic sequencing technology. RESULTS: After high-fat and high-protein diet intervention, Chao1, observed species index, and operational taxonomic units number decreased in the model group (P > .05), while the Shannon, Simpson, Pielou's evenness, and Goods coverage indices increased (P > .05). The principal coordinate analysis showed that the composition of lactase-producing bacteria differed between the normal group and model group (P < .05). The lactase-producing bacterial source in the intestinal contents of mice was Actinobacteria, Firmicutes, and Proteobacteria, of which Actinobacteria was the most abundant phylum. At the genus level, both groups had their unique genera, respectively. Compared to the normal group, the abundance of Bifidobacterium, Rhizobium, and Sphingobium increased, while Lachnoclostridium, Lactobacillus, Saccharopolyspora, and Sinorhizobium decreased in the model group. CONCLUSION: High-fat and high-protein diet altered the structure of lactase-producing bacteria in the intestinal contents, elevating the abundance of dominant lactase-producing bacteria, while decreasing the richness of lactase-producing bacteria, which may further induce the occurrence of diarrhea.

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.

Effects of sweeteners on host physiology by intestinal mucosal microbiota: Example-addition sweeteners in Qiweibaizhu Powder on intestinal mucosal microbiota of mice with antibiotic-associated diarrhea.

In recent years, sweeteners have gained massive popularity under the trend of limiting sugar intake. Our previous study found that Qiweibaizhu Powder (QWBZP) could improve gut microbiota dysbiosis and has good efficacy in treating antibiotic-associated diarrhea (AAD). In this study, we investigated the effects of sucrose, sorbitol, xylitol, and saccharin on the intestinal mucosal microbiota of AAD mice treated with QWBZP. When the AAD model was constructed by being gavaged mixed antibiotic solution, Kunming mice were randomly assigned to seven groups: the control (mn) group, the ADD (mm) group, the QWBZP (mq) group, the saccharin + QWBZP (mc) group, the sucrose + QWBZP (ms) group, the xylito + QWBZP (mx) group, and the sorbitol + QWBZP (msl) group. Subsequently, 16S rRNA gene amplicon sequencing was used to analyze the intestinal mucosal microbiota composition and abundance. The results showed that feces from AAD mice were diluted and wet and improved diarrhea symptoms with QWBZP and sorbitol. In contrast, the addition of sucrose, saccharin, and xylitol delayed the healing of diarrhea. The relative abundance of intestinal mucosal microbiota showed Glutamicibacter, Robinsoniella, and Blautia were characteristic bacteria of the mx group, Candidatus Arthromitus, and Bacteroidales_S24-7_group as the typical bacteria of the mn group, Clostridium_innocuum_group as the distinct bacteria of the mm group. Mycoplasma and Bifidobacterium as the characteristic bacteria of the ms group. Correlation analysis of typical bacterial genera with metabolic functions shows that Blautia negatively correlates with D-Glutamine and D-glutamate metabolism. Bacteroidales_S24-7_group has a significant negative correlation with the Synthesis and degradation of ketone bodies. The study confirmed that sucrose, sorbitol, xylitol, and saccharin might further influence metabolic function by altering the intestinal mucosal microbiota. Compared to the other sweetener, adding sorbitol to QWBZP was the best therapeutic effect for AAD and increased the biosynthesis and degradation activities. It provides the experimental basis for applying artificial sweeteners in traditional Chinese medicine (TCM) as a reference for further rational development and safe use of artificial sweeteners.

Lactase bacteria in intestinal mucosa are associated with diarrhea caused by high-fat and high-protein diet.

BACKGROUND: Excessive fat and protein in food can cause diarrhea by disturbing the intestinal microecology. Lactase is a functional enzyme strongly associated with diarrhea, while lactase bacteria in the intestine are an important source of microbial lactase. Therefore, we reconnoiter the relationship between diarrhea induced by a high-fat and high-protein diet (HFHPD) and intestinal mucosal lactase bacteria from the perspective of functional genes. RESULT: Operational Taxonomic Units (OTUs) were 23 and 31 in the normal group (NM) and model group (MD), respectively, and 11 of these were identical. The Chao1 and Observed specie indexes in the MD were higher than those in the NM, but this was not significant (P > 0.05). Meanwhile, the Principal coordinate analysis (PCoA) and Adonis test showed that the community structures of lactase bacteria in NM and MD were significantly different (P < 0.05). In taxonomic composition, lactase bacteria on the intestinal mucosa were sourced from Actinobacteria and Proteobacteria. Where Actinobacteria were higher in NM, and Proteobacteria were higher in MD. At the genus level, Bifidobacterium was the dominant genus (over 90% of the total). Compared to NM, the abundance of Bifidobacterium were lower in MD, while MD added sources for lactase bacteria of Rhizobium, Amycolatopsis, and Cedecea. CONCLUSIONS: Our data demonstrate that HFHPD altered the community structure of lactase bacteria in the intestinal mucosa, decreased the abundance of the critical lactase bacteria, and promoted the occurrence of diarrhea.

Baohe pill decoction for diarrhea induced by high-fat and high-protein diet is associated with the structure of lactase-producing bacterial community.

Background: This study investigated the effects of Baohe pill decoction on the diversity and community composition of lactase-producing bacteria in the intestinal contents of mice with diarrhea induced by high-fat and high-protein diet, which provided an experimental basis for the study on the therapeutic mechanism of Baohe pill decoction. Materials and methods: The Traditional Chinese Medicine Systems Pharmacology (TCMSP), DisGeNET, UniProt, National Center for Biotechnology Information (NCBI), and GeneCards databases were used to collect the potential targets with active ingredients of Baohe pill decoction, diarrhea, and lactase, and then construct correlation networks. Fifteen Kunming mice were randomly divided into the control group (CN), natural recovery group (NR), and Baohe pill decoction treatment group (BHP), with five mice in each group. After constructing a mouse diarrhea model by HFHPD induction, BHP was gavaged with Baohe pill decoction, and the other groups were gavaged with distilled water of equal. The intestinal contents were collected from ileal to jejunal and analyzed using metagenomic sequencing to characterize the intestinal content of lactase-producing bacteria in mice. Results: The core active ingredients related to diarrhea in Baohe pill decoction were quercetin, luteolin, kaempferol, forsythin, and wogonin. And there was no intersection between the potential targets with the active ingredient of Baohe pill, lactase, and diarrhea. After the intervention of Baohe pill decoction, the Observed species, Chao1 index, and Operational Taxonomic Units (OTU) number increased in BHP (P > 0.05), while the Pielous evenness and Shannon index decreased (P > 0.05). In Beta diversity, the community structure of the NR was significantly different from CN and BHP (P < 0.05), and the community structure of the CN was not significant difference from BHP (P > 0.05). Compared to NR, the relative abundance of Bifidobacterium and Amycolatopsis increased, while the relative abundance of Lachnoclostridium, Sinorhizobium, Cedecea, and Escherichia decreased in BHP, but none of the significant differences (P > 0.05). Conclusion: The therapeutic effect of Baohe pill decoction on diarrhea induced by HFHPD does not appear to involve the body's lactase gene targets directly, but is associated with the change of the construction of lactase-producing bacterial communities.

Importance of Dendrobium officinale in improving the adverse effects of high-fat diet on mice associated with intestinal contents microbiota.

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.

Hypertension of liver-yang hyperactivity syndrome induced by a high salt diet by altering components of the gut microbiota associated with the glutamate/GABA-glutamine cycle.

The gut microbiota and metabolites are closely related to hypertension; however, the changes in the composition of the gut microbiome and metabolites linking a high salt diet to elevated blood pressure are not established. In this study, traditional Chinese medicine (TCM) syndrome of hypertension caused by high salt had been diagnosed and the pathogenesis of hypertension was explored from the perspective of intestinal microecology. Rats in a high salt diet-induced hypertension group (CG) and normal group (CZ) were compared by 16S rRNA gene full-length sequencing and liquid chromatography and mass spectrometry to identify differences in the bacterial community structure, metabolites, and metabolic pathways. Hypertension induced by a high salt diet belongs to liver-Yang hyperactivity syndrome. Alpha and beta diversity as well as the composition of microbiota from the phylum to species levels differed substantially between the CG and CZ groups. In an analysis of differential metabolites in the intestines, a high salt diet mainly affected the metabolism of amino acids and their derivatives; in particular, γ-aminobutyric acid (GABA) was down-regulated and glutamic acid and its derivatives were up-regulated under a high salt diet. Based on a KEGG analysis, high salt intake mainly altered pathways related to GABA and the glutamate/glutamine metabolism, such as the GABAergic synapse pathway and glutamatergic synapse pathway. The correlation analysis of differential gut microbes and differential metabolites suggested that a high salt diet promoted hypertension via the inhibition of Clostridiaceae_1 growth and alterations in the GABA metabolic pathway, leading to increased blood pressure. These findings suggest that a high salt diet induces hypertension of liver-Yang hyperactivity syndrome by mediating the microbiota associated with the glutamate/GABA-glutamine metabolic cycle via the gut-brain axis.

The Effect of Qiweibaizhu Powder Crude Polysaccharide on Antibiotic-Associated Diarrhea Mice Is Associated With Restoring Intestinal Mucosal Bacteria.

Background: Qiweibaizhu 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 Methods: Eighteen 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. Results: The 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. Conclusion: The 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.

Gut microbiota characteristics in mice with antibiotic-associated diarrhea.

BACKGROUND: Antibiotic-associated diarrhea (AAD), defined as diarrhea that occurs in association with the administration of antibiotics and without another clear etiology, is one of the most common adverse drug events of antibiotics therapy. We established a diarrhea model induced by gentamycin and cefradine to investigate the microbiota characteristics in the intestinal lumen of mice with AAD and provide insights into noteworthy bacteria related to gentamicin and cefradine-associated diarrhea. RESULTS: The number of OTUs in the model group and the normal group was 983 and 2107, respectively, and 872 identical OTUs were shared between two groups. Species richness and species diversity of intestinal microbe were altered by antibiotics administration. PCoA showed a clear separation between AAD and health control. The dominant phyla of AAD mice were Firmicutes (52.63%) and Proteobacteria (46.37%). Among the genus with top 20 abundance, the relative abundance of 7 genera, Ruminococcus, Blautia, Enterococcus, Eubacterium, Clostridium, Coprococcus, and Aerococcus, were enriched in the model group. Based upon the LEfSe analysis, Enterococcus, Eubacterium, Ruminococcus, and Blautia were identified as potential biomarkers for AAD. CONCLUSIONS: The bacterial diversity of the intestinal lumen was diminished after gentamicin and cefradine administration. The alterations in the abundance and composition of gut microbiota further led to the dysfunction of gut microbiota. More specifically, gentamicin and cefradine significantly increased the abundance of the opportunistic pathogens, of which Enterococcus and Clostridium were the most prominent and most worthy of attention.

Role of tryptophan-metabolizing microbiota in mice diarrhea caused by Folium sennae extracts.

BACKGROUND: Although reports have provided evidence that diarrhea caused by Folium sennae can result in intestinal microbiota diversity disorder, the intestinal bacterial characteristic and specific mechanism are still unknown. The objective of our study was to investigate the mechanism of diarrhea caused by Folium sennae, which was associated with intestinal bacterial characteristic reshaping and metabolic abnormality. RESULTS: For the intervention of Folium sennae extracts, Chao1 index and Shannon index were statistical decreased. The Beta diversity clusters of mice interfered by Folium sennae extracts were distinctly separated from control group. Combining PPI network analysis, cytochrome P450 enzymes metabolism was the main signaling pathway of diarrhea caused by Folium sennae. Moreover, 10 bacterial flora communities had statistical significant difference with Folium sennae intervention: the abundance of Paraprevotella, Streptococcus, Epulopiscium, Sutterella and Mycoplasma increased significantly; and the abundance of Adlercreutzia, Lactobacillus, Dehalobacterium, Dorea and Oscillospira reduced significantly. Seven of the 10 intestinal microbiota communities were related to the synthesis of tryptophan derivatives, which affected the transformation of aminotryptophan into L-tryptophan, leading to abnormal tryptophan metabolism in the host. CONCLUSIONS: Folium sennae targeted cytochrome P450 3A4 to alter intestinal bacterial characteristic and intervene the tryptophan metabolism of intestinal microbiota, such as Streptococcus, Sutterella and Dorea, which could be the intestinal microecological mechanism of diarrhea caused by Folium sennae extracts.

Bacterial Lactase Gene Characteristics in Intestinal Contents of Antibiotic-Associated Diarrhea Mice Treated with Debaryomyces hansenii.

BACKGROUND Debaryomyces hansenii exhibits a therapeutic effect on antibiotic-associated diarrhea (AAD) by promoting the growth of beneficial intestinal bacteria. Previous research has reported that AAD involves not only dysbacteriosis but also dysfunction of the activity of intestinal enzymes (such as lactase). Enzyme activities can be influenced by many other factors, such as gene expression. The present study showed that D. hansenii has a curative effect on AAD at the lactase gene level. MATERIAL AND METHODS The effect of D. hansenii on the lactase gene from intestinal bacteria in AAD mice was investigated. The diarrhea model was established with a gentamycin sulfate and cefradine capsule mixture. The antibiotic mixture (23.33 mL·kg⁻¹·day⁻¹) was intragastrically administered for 5 days. Subsequently, half of the diarrhea mice were treated with D. hansenii twice a day for 3 days while the other mice were intragastrically administered with the same volume of distilled water. Next, the intestinal contents were collected, and metagenomic DNA was extracted for high-throughput sequencing analysis. RESULTS The Chao1 and Shannon indices decreased significantly following treatment with D. hansenii (P<0.01 and P<0.05, respectively). Moreover, the clusters in the D. hansenii group mice were quite different from those in the normal group mice and model group mice. Following treatment with D. hansenii, the quantity of lactase genes in Enterobacter sp. 638 and Modestobacter increased markedly, and the richness of intestinal bacterial lactase genes in Fretibacterium recovered. CONCLUSIONS D. hansenii altered the lactase-producing bacterial community structure and promoted the growth of several critical lactase-producing bacteria, such as Enterobacter sp. 638 and Modestobacter.

Bacterial lactase genes diversity in intestinal mucosa of mice with dysbacterial diarrhea induced by antibiotics.

The current study aimed at exploring the diversity of bacterial lactase genes in the intestinal mucosa of mice with dysbacterial diarrhea induced by antibiotics and to provide experimental basis for antibiotics-induced diarrhea. Mice model of dysbacterial diarrhea was established by gastric perfusion with mixture of cephradine capsules and gentamicin sulfate (23.33 mL kg-1 d-1), twice a day and continuously for 5 days. Intestinal mucosa from jejunum to ileum was collected, and bacterial metagenomic DNA was extracted for Miseq metagenome sequencing to carry out diversity analysis. The results showed that specific operational taxonomic units (OTUs) were 45 in the control group and 159 in the model group. The Chao1, ACE, Shannon and Simpson indices in model group were significantly higher (P < 0.01 or P < 0.05) than control group. Principal component analysis (PCA) and box chart of the control group were relatively intensive, while in the model group, they were widely dispersed. Furthermore, the inter-group box area was higher than that in the intra-group. Compared with the model group, the abundance of bacterial lactase genes in Proteobacteria from the intestinal mucosa of the control group was higher, but lower in Actinobacteria and unclassified bacteria. At the genus level, the relative abundance of bacterial species and taxon units in model group was obviously increased (P < 0.05). Our results indicate that antibiotics increased the diversity and abundance of bacterial lactase genes in the intestinal mucosa, as the abundance of Betaproteobacteria, Cupriavidus, Ewingella, Methyloversatilis, Rhodocyclaceae and Rhodocyclales. In addition, antibiotics become an additional source for lactase genes of Ewingella, Methyloversatilis, Mycobacterium, Microbacterium, Beutenberqia and Actinomyces.

Diversity of bacterial lactase genes in intestinal contents of mice with antibiotics-induced diarrhea.

AIM: To investigate the diversity of bacterial lactase genes in the intestinal contents of mice with antibiotics-induced diarrhea. METHODS: Following 2 d of adaptive feeding, 12 specific pathogen-free Kunming mice were randomly divided into the control group and model group. The mouse model of antibiotics-induced diarrhea was established by gastric perfusion with mixed antibiotics (23.33 mL·kg-1·d-1) composed of gentamicin sulfate and cephradine capsules administered for 5 days, and the control group was treated with an equal amount of sterile water. Contents of the jejunum and ileum were then collected and metagenomic DNA was extracted, after which analysis of bacterial lactase genes using operational taxonomic units (OTUs) was carried out after amplification and sequencing. RESULTS: OTUs were 871 and 963 in the model group and control group, respectively, and 690 of these were identical. There were significant differences in Chao1 and ACE indices between the two groups (P < 0.05). Principal component analysis, principal coordination analysis and nonmetric multidimensional scaling analyses showed that OTUs distribution in the control group was relatively intensive, and differences among individuals were small, while in the model group, they were widely dispersed and more diversified. Bacterial lactase genes from the intestinal contents of the control group were related to Proteobacteria, Actinobacteria, Firmicutes and unclassified bacteria. Of these, Proteobacteria was the most abundant phylum. In contrast, the bacterial population was less diverse and abundant in the model group, as the abundance of Bradyrhizobium sp. BTAi1, Agrobacterium sp. H13-3, Acidovorax sp. KKS102, Azoarcus sp. KH32C and Aeromonas caviae was lower than that in the control group. In addition, of the known species, the control group and model group had their own unique genera, respectively. CONCLUSION: Antibiotics reduce the diversity of bacterial lactase genes in the intestinal contents, decrease the abundance of lactase gene, change the lactase gene strains, and transform their structures.

Effects of Debaryomyces hansenii treatment on intestinal microorganisms in mice with antibiotics-induced diarrhea.

To investigate the influence of Debaryomyces hansenii treatment on intestinal microorganisms in mice with antibiotics-induced diarrhea, mouse model of antibiotics-induced diarrhea was created by gavaging mice with mixed antibiotics (23.33 mL/kg/days) composed of gentamycin sulfate and cefradine for 5 days. Mice with the symptom of diarrhea were then treated with D. hansenii by intragastric administration. The control group mice were given with sterile water. After 4 day treatment, total DNA of intestinal microflora of treated and control mice was extracted, and their quantities were measured by sequencing the V4 region of 16S rDNA. The results showed that when compared to the control (sterile water), treatment with D. hansenii increased the operational taxonomic units (OTUs) of intestinal bacteria. The Chao index in diarrhea treated group was higher than diarrhea control group and was similar to healthy control group, while all differences had no significance (P > 0.05). D. hansenii treatment increased the Shannon index but not significantly (P > 0.05). Moreover, there was not significant impact on density and diversity of intestinal bacterial population at phylum and genus levels (P > 0.05). Interestingly, D. hansenii treatment recovered the population density of certain bacterium species, such as Bacteroidaceae (in family level) (P < 0.05). Our results indicate that D. hansenii has potency of adjusting the density and diversity of intestinal bacteria and recovering the population density of Bacteroidaceae in family level.