Chlorogenic Acid Ameliorates Experimental Colitis by Promoting Growth of Akkermansia in Mice

Microbial network disturbances in relapsing refractory Crohn's disease

Inflammatory bowel diseases (IBD) can be broadly divided into Crohn's disease (CD) and ulcerative colitis (UC) from their clinical phenotypes. Over 150 host susceptibility genes have been described, although most overlap between CD, UC and their subtypes, and they do not adequately account for the overall incidence or the highly variable severity of disease. Replicating key findings between two long-term IBD cohorts, we have defined distinct networks of taxa associations within intestinal biopsies of CD and UC patients. Disturbances in an association network containing taxa of the Lachnospiraceae and Ruminococcaceae families, typically producing short chain fatty acids, characterize frequently relapsing disease and poor responses to treatment with anti-TNF-α therapeutic antibodies. Alterations of taxa within this network also characterize risk of later disease recurrence of patients in remission after the active inflamed segment of CD has been surgically removed.

JinQi Jiangtang Tablet Regulates Gut Microbiota and Improve Insulin Sensitivity in Type 2 Diabetes Mice

BACKGROUND

Gut microbiota modulates the barrier function and host inflammatory state in metabolic disease. JinQi Jiangtang (JQJT) tablets are a traditional Chinese medicine for the treatment of diabetes. However, the low bioavailability of its chemical compositions makes it hard to explain the pharmacological mechanisms.

METHOD

Diabetic mice were orally treated with JQJT tablets for 5 weeks. Fasting blood glucose and the level of HbA1c were measured, and ITT were conducted to determine the insulin improvement effect of JQJT tablets. The regulation effect on gut microbiota was assessed by 16S rRNA gene sequencing on an Illumina HiSeq platform. The concentration of short-chain fatty acids was measured by HS-GC/MS. D-LA leakage experiment and PAS staining were used to check the function of the gut barrier. The levels of the inflammatory cytokines were determined by using an ELISA kit.

RESULTS

This study showed that JQJT tablets downregulated fasting blood glucose and HbA1c and regulated gut microbiota. JQJT tablet-treated groups exhibited a more sensitive reaction after a small-dose injection of short-acting insulin. T2DM mice treated with JQJT tablets showed a higher abundance of Akkermansia spp. and lower abundance of Desulfovibrio. JQJT tablets increased the concentration of acetic acid, propionic acid, and butyric acid; in particular, butyric acid was significantly increased with respect to the MOD group. Gut mucosal barrier function experiment showed that the level of D-LA was obviously decreased in JQJT tablet-treated groups compared with the model group and the number of goblet cells was significantly increased by JQJT tablet treatment. JQJT tablets could also reduce the levels of TNF-α, IL-6, and MCP-1, which were related to insulin resistance.

CONCLUSION

We demonstrated that JQJT tablets could improve T2DM insulin resistance, regulating the gut microbiota and promoting the production of SCFAs. The mechanism was related to increasing the gut barrier function and reducing the host inflammatory reaction.

Intestinal Anti-Inflammatory Activity of the Aqueous Extract from Ipomoea asarifolia in DNBS-Induced Colitis in Rats

Inflammatory bowel disease is triggered by an uncontrolled immune response associated with genetic, environmental, and intestinal microbiota imbalance. Ipomoea asarifolia (IA), popularly known as “salsa” or “brave salsa”, belongs to the Convolvulaceae family. The aim of this approach was to study the preventive effect of IA aqueous extract in 2,4-dinitrobenzene sulfonic acid (DNBS)-induced colitis in rats. Rats pretreated with IA extract or sulfasalazine (SSZ) received intracolonic instillation of DNBS in 50% ethanol (v/v). IA extract presented a protective effect against intestinal inflammation, with improvement in the disease activity index and macroscopic damage. IA or SSZ significantly reduced myeloperoxidase activity, and also down-regulation of the gene expression of JNK1, NF-κβ-p65, STAT3, and decreased levels of TNFα, IL-1β, and increased IL-10, associated with a significant improvement of oxidative stress, in addition to a reduction in MDA and an increase of glutathione in colonic tissue. The protective effect of the extract was also confirmed in histological evaluation, showing preservation of the colonic cytoarchitecture. Immunohistochemical analysis revealed down-regulation of NF-κβ-p65, iNOS, IL-17, and up-regulation of SOCs-1 and MUC-2. IA extract presents antioxidant and anti-inflammatory intestinal properties, and proved to be a potential application for preventing damage induced by DNBS.

Geniposide and Chlorogenic Acid Combination Ameliorates Non-alcoholic Steatohepatitis Involving the Protection on the Gut Barrier Function in Mouse Induced by High-Fat Diet

Gut-liver axis is increasingly recognized to be involved in the pathogenesis and progression of non-alcoholic fatty liver disease (NAFLD). The gut microbiota and intestinal permeability have been demonstrated to be the key players in the gut-liver cross talk in NAFLD. Geniposide and chlorogenic acid (GC) combination is derived from a traditional Chinese medicine, Qushi Huayu Decoction (QHD), which has been used in clinic for NAFLD treatment for decades in China and validated in multiple animal models of NAFLD. GC combination previously has been demonstrated to treat NAFLD via modulation on the gut microbiota composition. In the present study, the effects of GC combination on gut barrier function in NAFLD were evaluated, and QHD and sodium butyrate (NaB), the intestinal mucosa protectant, were used as positive control. The therapeutic effect of GC combination on NAFLD were confirmed by amelioration on non-alcoholic steatohepatitis (NASH) induced by high-fat diet (HFD) in mouse, which was comparable to that of QHD. Simultaneously, GC combination was found to reduce the signaling of gut-derived lipopolysaccharide (LPS) including hepatic LPS binding protein, Toll like receptor 4, interleukin-1β, tumor necrosis factor –α, and Kupffer cells infiltration. Furthermore, GC combination reduced LPS and D-lactate in plasma, restoring the colonic tight junction (TJ) expression and inhibited colonic TJs disassembly by down-regulation on RhoA/ROCK signaling in NASH induced by HFD. On the other hand, NASH was also alleviated in NaB group. The results of the present study suggested the important role of protection on gut barrier function in NAFLD treatment, which contributed to the therapeutic effects of GC combination on NASH.

Chlorogenic acid attenuates high-carbohydrate, high-fat diet-induced cardiovascular, liver, and metabolic changes in rats

Chlorogenic acid as a constituent of coffee is consumed regularly in the human diet. Chlorogenic acid intake has been associated with decreased risk of cardiovascular disease and type 2 diabetes. We hypothesized that chlorogenic acid would improve cardiovascular, liver, and metabolic responses in a rat model of metabolic syndrome induced by a high-carbohydrate, high-fat diet. Male Wistar rats (8-9 weeks old, 335 ± 2 g, n = 48) were divided into 4 groups and fed with corn starch diet (16 weeks); corn starch diet with chlorogenic acid in food for the last 8 weeks; high-carbohydrate, high-fat diet (16 weeks); or high-carbohydrate, high-fat diet with chlorogenic acid (~100 mg/kg/d) in food for the last 8 weeks. In high-carbohydrate, high-fat diet-fed rats, chlorogenic acid reduced energy intake and food efficiency to reduce visceral fat, especially retroperitoneal fat, and abdominal circumference; reversed the elevated systolic blood pressure; and attenuated left ventricular diastolic stiffness with reduced collagen deposition and infiltration of inflammatory cells in the left ventricle. Chlorogenic acid decreased inflammation and fat deposition in the liver along with reduced plasma liver enzyme activities of obese rats but did not change the plasma lipid profile. Chlorogenic acid increased diversity of gut microbiota, which may improve overall metabolism in the body. Thus, chronic dietary chlorogenic acid attenuated diet-induced inflammation as well as cardiovascular, liver, and metabolic changes, suggesting that chlorogenic acid has potential for further clinical evaluation.

Akkermansia muciniphila strain ATCC BAA-835 does not promote short-term intestinal inflammation in gnotobiotic interleukin-10-deficient mice

Akkermansia muciniphila is a common member of the intestinal microbiota of healthy human individuals. Its abundance is negatively associated with inflammatory bowel disease and metabolic disorders and the oral administration of A. muciniphila improves the symptoms of metabolic disease in mice. Therefore, A. muciniphila is a promising candidate for the treatment of type-2 diabetes and obesity. However, some studies using animal models of intestinal inflammation reported that A. muciniphila may exacerbate gut inflammation. Because of these contradictory reports the present study aimed to clarify the role of A. muciniphila in the development of intestinal inflammation and the conditions promoting it. For this purpose, the short-term colitogenic potential of A. muciniphila strain ATCC BAA-835 was investigated in colitis-prone, gnotobiotic IL-10-deficient (Il10^-/-) mice. Il10^-/- mice mono-associated with A. muciniphila showed no signs of intestinal inflammation based on body-weight change, histopathological scoring and inflammatory markers. Additional association of the mice with the colitogenic Escherichia coli strain NC101 led to cecal but not colonic inflammation. However, the severity of the inflammation did not exceed that observed in mice mono-associated with E. coli NC101. Il10^-/- mice colonized with a simplified human intestinal microbiota showed increased histopathology, but no increase in inflammatory markers. Furthermore, co-colonization with A. muciniphila did not modify histopathology. The turnover of intestinal mucus was similar in all groups despite the mucus-degrading property of A. muciniphila. Overall, the data do not support a short-term pro-inflammatory effect of A. muciniphila strain ATCC BAA-835 in the Il10^-/- mouse model for inflammatory bowel disease.

Chronic kidney disease, uremic milieu, and its effects on gut bacterial microbiota dysbiosis

Several lines of evidence suggest that gut bacterial microbiota is altered in patients with chronic kidney disease (CKD), though the mechanism of which this dysbiosis takes place is not well understood. Recent studies delineated changes in gut microbiota in both CKD patients and experimental animal models using microarray chips. We present 16S ribosomal RNA gene sequencing of both stool pellets and small bowel contents of C57BL/6J mice that underwent a remnant kidney model and establish that changes in microbiota take place in the early gastrointestinal tract. Increased intestinal urea concentration has been hypothesized as a leading contributor to dysbiotic changes in CKD. We show that urea transporters (UT)-A and UT-B mRNA are both expressed throughout the whole gastrointestinal tract. The noted increase in intestinal urea concentration appears to be independent of UTs' expression. Urea supplementation in drinking water resulted in alteration in bacterial gut microbiota that is quite different than that seen in CKD. This indicates that increased intestinal urea concentration might not fully explain the CKD- associated dysbiosis.

Modulating Effects of Dicaffeoylquinic Acids from Ilex kudingcha on Intestinal Microecology in Vitro

Dietary polyphenols have been considered as novel prebiotics, and polyphenols could exert their functions through modulating intestinal microbiota. The diverse bioactivities of kudingcha could derive from its phenolic compounds, but the effects of dicaffeoylquinic acids (diCQAs) from Ilex kudingcha on intestinal microbiota have not been investigated. In the present study, high-throughput sequencing and anaerobic fermentation in vitro were utilized to investigate the microecology-modulating function of I. kudingcha diCQAs. As a result, diCQAs raised the diversity and exhibited a more considerable impact than a carbon source on the microbial profile. DiCQAs increased the relative abundances of Alistipes, Bacteroides, Bifidobacterium, Butyricimonas, Clostridium sensu stricto, Escherichia/Shigella, Parasutterella, Romboutsia, Oscillibacter, Veillonella, Phascolarctobacterium, Lachnospiracea incertae sedis, Gemmiger, Streptococcus, and Haemophilus and decreased the relative abundances of Ruminococcus, Anaerostipes, Dialister, Megasphaera, Megamonas, and Prevotella. DiCQAs also affected the generation of short-chain fatty acids through microbiota. The contents of acetic and lactic acids were raised, while the production of propionic and butyric acids was reduced. Conclusively, diCQAs from I. kudingcha had significant modulating effects on intestinal microbiota in vitro, which might be the fundamental of diCQAs exerting their bioactivities.