Improvement of intestinal microflora balance by polysaccharide from Physalis alkekengi var. francheti

Akkermansia muciniphila and Alcohol-Related Liver Diseases. A Systematic Review

SCOPE

Akkermansia muciniphila (A. muciniphila) are Gram negative commensal bacteria, degrading mucin in the intestinal mucosa, modulating intestinal permeability and inflammation in the digestive tract, liver, and blood. Some components can promote the relative abundance of A. muciniphila in the gut microbiota, but lower levels of A. muciniphila are more commonly found in people with obesity, diabetes, metabolic syndromes, or inflammatory digestive diseases. Over-intake of ethanol can also induce a decrease of A. muciniphila, associated with dysregulation of microbial metabolite production, impaired intestinal permeability, induction of chronic inflammation, and production of cytokines.

METHODS AND RESULTS

Using a PRISMA search strategy, a review is performed on the bacteriological characteristics of A. muciniphila, the factors capable of modulating its relative abundance in the digestive tract and its probiotic use in alcohol-related liver diseases (alcoholic hepatitis, cirrhosis, hepatocellular carcinoma, hepatic transplantation, partial hepatectomy).

CONCLUSION

Several studies have shown that supplementation with A. muciniphila can improve ethanol-related hepatic pathologies, and highlight the interest in using this bacterial species as a probiotic.

Antiviral Mechanism of Tea Polyphenols against Porcine Reproductive and Respiratory Syndrome Virus

Neither inactivated nor attenuated vaccines can effectively prevent and control the infection and spread of porcine reproductive and respiratory syndrome virus (PRRSV). Therefore, it is necessary to broaden new horizons and to conceive effective preventive strategies. The main components of Tea polyphenol (TPP) are catechins and their derivatives. TPP has many physiological activities and has certain antiviral and antifungal effects. However, whether TPP shows anti-PRRSV activity remains unclear. We found that TPP effectively inhibited PRRSV infection in Marc-145 cells by suppressing the stages of viral attachment, internalization, replication, and release. TPP exhibited a potent anti-PRRSV effect regardless of pre-treatment or post-treatment. In addition, we demonstrated that TPP restrained PRRSV-induced p65 entry into the nucleus to suppress the activation of the NF-κB signaling pathway, which ultimately leads to the inhibition of the expression of inflammatory cytokines. Furthermore, TPP limited the synthesis of viral non-structural protein 2 (nsp2), the core component of viral replication transcription complexes, which may contribute to the inhibition of viral RNA replication. TPP has the potential to develop into an effective antiviral agent for PRRSV prevention and control in the future.

Intervention with the crude polysaccharides of Physalis pubescens L. mitigates colitis by preventing oxidative damage, aberrant immune responses, and dysbacteriosis

In this study, a colitis mouse model induced by dextran sulfate sodium (DSS) was used to investigate the mechanisms of action of an extract of crude polysaccharides (POL) from Physalis pubescens L. as a dietary intervention for colitis. Our results showed that the administration of POL prior to DSS-induced colitis protected the colon mucosal layer; maintained intestinal barrier integrity; alleviated oxidative damage; and lowered neutrophil infiltration by downregulating intercellular cell adhesion molecule-1 and monocyte chemoattractant protein-1 expression. More importantly, POL pretreatment reduced the expression of the proinflammatory factors tumor necrosis factor-α, inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2), thereby modulating the nuclear factor-κB/iNOS-COX-2 signal transduction pathway. In addition, POL reversed DSS-induced gut dysbiosis, accompanied by reducing the relative abundance of Helicobacter, Mucispirillum, and Erysipelatoclostridium. In conclusion, POL ameliorated DSS-induced intestinal injury in mice, indicating that POL could be a useful dietary nutrient to protect against colitis. PRACTICAL APPLICATION: Physalis pubescens L. is an edible fruit. The results of this study show that the intervention with Physalis pubescens L. crude polysaccharides may help prevent ulcerative colitis.

Prebiotic-Like Effects of Water Soluble Chitosan on the Intestinal Microflora in Mice

In the present work, water soluble chitosan (WSC) was prepared and growth curves of Lactobacillus delbrueckii and Escherichia coli were examined in vitro. In vivo, mice were randomly divided into three groups (10 mice in each group), treated with water, 1 g/kg WSC and 0.25 g/kg of WSC respectively for 24 days. Subsequently, levofloxacin (65 mg/kg) was given for 6 days. The dynamic changes of bacterial communities were evaluated by denaturing gradient gel electrophoresis periodically. L. delbrueckii and E. coli have been inhibited by WSC in vitro. The bacteria from the genera of Bacteroides, Lactobacillus, Enterococcus and Devosia were dominant gut flora in the intestinal tract of mice. The growth of Lactobacillus has been dramatically stimulated, whereas Enterococcus faecium and Parabacteroides distasonis which were opportunistic bacterial pathogens have been inhibited. So WSC can be considered as a new food supplement to protect the intestinal microflora and regulate imbalance.

Effects of polysaccharide from Physalis alkekengi var. francheti on liver injury and intestinal microflora in type-2 diabetic mice

CONTEXT

Diabetic liver injury is a serious diabetic complication. The alterations of intestinal microbiota play an important role in induction and promotion of liver injury progression. Physalis alkekengi L. var. francheti (Mast.) Makino (Solanaceae) has been used as a water decoction for treating diabetes.

OBJECTIVE

To study the effects of a polysaccharide (PPSB) from Physalis alkekengi var. francheti on liver injury and intestinal microflora in type-2 diabetic mice.

MATERIALS AND METHODS

Streptozotocin (160 mg/kg) was injected i.p. for 3 days to build model. The diabetic mice were randomly divided into four groups together with control group (10 mice in each group). The doses of PPSB were 50 and 100 mg/kg, respectively. After 5 weeks administration, level of blood glucose, ALT and AST were measured. Alterations of intestinal microflora, and protein expression of TGF-β1, TNF-α and DCN were detected.

RESULTS

Level of blood glucose decreased from (25.38 ± 2.21) mmol/L to (18.01 ± 2.53) mmol/L, ALT and AST decreased to (24.67 ± 4.86) U/L and (30.84 ± 7.50) U/L in PPSB-H group. Lactobacillus, Clostridium butyricum, and Bacteroides increased remarkably with increasing concentration of PPSB, but Enterobacter was inhibited. The relative expression of TGF-β1 and TNF-α decreased to (0.70 ± 0.17) and (0.39 ± 0.06), and the expression of DCN increased to (0.65 ± 0.13).

DISCUSSION AND CONCLUSIONS

Probiotics have been promoted by PPSB, and protein expressions have been modulated in the progression of liver injury. PPSB could be used as a natural agent for treating diabetic liver injury and intestinal microflora imbalance.

Gastric and enterohepatic helicobacters other than Helicobacter pylori

During the past year, research on non-Helicobacter pylori species has intensified. H. valdiviensis was isolated from wild birds, and putative novel species have been isolated from Bengal tigers and Australian marsupials. Various genomes have been sequenced: H. bilis, H. canis, H. macacae, H. fennelliae, H. cetorum, and H. suis. Several studies highlighted the virulence of non-H. pylori species including H. cinaedi in humans and hyperlipidemic mice or H. macacae in geriatric rhesus monkeys with intestinal adenocarcinoma. Not surprisingly, increased attention has been paid to the position of Helicobacter species in the microbiota of children and animal species (mice, chickens, penguins, and migrating birds). A large number of experimental studies have been performed in animal models of Helicobacter induced typhlocolitis, showing that the gastrointestinal microbial community is involved in modulation of host pathways leading to chronic inflammation. Animal models of H. suis, H. heilmannii, and H. felis infection have been used to study the development of severe inflammation-related pathologies, including gastric MALT lymphoma and adenocarcinoma.