Eubiotic properties of rifaximin: Disruption of the traditional concepts in gut microbiota modulation

Antibiotics are usually prescribed to cure infections but they also have significant modulatory effects on the gut microbiota. Several alterations of the intestinal bacterial community have been reported during antibiotic treatment, including the reduction of beneficial bacteria as well as of microbial alpha-diversity. Although after the discontinuation of antibiotic therapies it has been observed a trend towards the restoration of the original condition, the new steady state is different from the previous one, as if antibiotics induced some kind of irreversible perturbation of the gut microbial community. The poorly absorbed antibiotic rifaximin seem to be different from the other antibiotics, because it exerts non-traditional effects additional to the bactericidal/bacteriostatic activity on the gut microbiota. Rifaximin is able to reduce bacterial virulence and translocation, has anti-inflammatory properties and has been demonstrated to positively modulate the gut microbial composition. Animal models, culture studies and metagenomic analyses have demonstrated an increase in Bifidobacterium, Faecalibacterium prausnitzii and Lactobacillus abundance after rifaximin treatment, probably consequent to the induction of bacterial resistance, with no major change in the overall gut microbiota composition. Antibiotics are therefore modulators of the symbiotic relationship between the host and the gut microbiota. Specific antibiotics, such as rifaximin, can also induce eubiotic changes in the intestinal ecosystem; this additional property may represent a therapeutic advantage in specific clinical settings.

Studies on blood enrichment and anti-tumor effects of combined Danggui Buxue Decoction,Fe and rhEPO based on colon cancer-related anemia model and gut microbiota modulation

Colon cancer-related anemia(CCRA)is mainly caused by systemic inflammation,intestinal bleeding,iron deficiency and chemotherapy-induced myelosuppression in colon cancer.However,the best therapeutic schedule and related mechanism on CCRA were still uncertain.Studies on blood enrichment and anti-tumor effects of combined Danggui Buxue Decoction(DBD),Fe and rhEPO based on CCRA and gut microbiota modulation were conducted in this paper.Here,CCRA model was successfully induced by subcutaneous inoculation of CT-26 and i.p.oxaliplatin,rhEPO+DBD high dosage+Fe(EDF)and rhEPO+DBD high dosage(ED)groups had the best blood enrichment effect.Attractively,EDF group also showed antitumor activity.The sequencing results of gut microbiota showed that compared to P group,the relative abundances of Lachnospiraceae and opportunistic pathogen(Odoribacter)in ED and EDF groups were decreased.Interestingly,EDF also decreased the relative abundances of cancer-related bacteria(Helicobacter,Lactococcus,Alloprevotella)and imbalance-inducing bacteria(Escherichia-Shigella and Parabacteroides)and increased the relative abundances of butyrate-producing bacteria(Ruminococcaceae_UCG-014),however,ED showed the opposite effects to EDF,this might be the reason of the smaller tumor volume in EDF group.Our findings proposed the best treatment combination of DBD,rhEPO and Fe in CCRA and provided theoretical basis and literature reference for CCRA-induced intestinal flora disorder and the regulatory mechanism of EDF.

Effect of berberine on hyperglycaemia and gut microbiota composition in type 2 diabetic Goto-Kakizaki rats

BACKGROUND A recent investigation showed that the prevalence of type 2 diabetes mellitus(T2DM)is 12.8%among individuals of Han ethnicity.Gut microbiota has been reported to play a central role in T2DM.Goto-Kakizaki(GK)rats show differences in gut microbiota compared to non-diabetic rats.Previous studies have indicated that berberine could be successfully used to manage T2DM.We sought to understand its hypoglycaemic effect and role in the regulation of the gut microbiota.AIM To determine whether berberine can regulate glucose metabolism in GK rats via the gut microbiota.METHODS GK rats were acclimatized for 1 wk.The GK rats were randomly divided into three groups and administered saline(Mo),metformin(Me),or berberine(Be).The observation time was 8 wk,and weight,fasting blood glucose(FBG),insulin,and glucagon-like peptide-1(GLP-1)were measured.Pancreatic tissue was observed for pathological changes.Additionally,we sequenced the 16S rRNA V3-V4 region of the gut microbiota and analysed the structure.RESULTS Compared with the Mo group,the Me and Be groups displayed significant differences in FBG(P<0.01)and GLP-1(P<0.05).A significant decrease in weight and homeostatic model assessment-insulin resistance was noted in the Be group compared with those in the Me group(P<0.01).The pancreatic islets of the Me-and Be-treated rats showed improvement in number,shape,and necrosis compared with those of Mo-treated rats.A total of 580 operational taxonomic units were obtained in the three groups.Compared to the Mo group,the Me and Be groups showed a shift in the structure of the gut microbiota.Correlation analysis indicated that FBG was strongly positively correlated with Clostridia_UCG-014(P<0.01)and negatively correlated with Allobaculum(P<0.01).Body weight showed a positive correlation with Desulfovibrionaceae(P<0.01)and a negative correlation with Akkermansia(P<0.01).Importantly,our results demonstrated that Me and Be could significantly decrease Bacteroidetes(P<0.01)and the Bacteroidetes/Firmicutes ratio(P<0.01).Furthermore,Muribaculaceae(P<0.01;P<0.05)was significantly decreased in the Me and Be groups,and Allobaculum(P<0.01)was significantly increased.CONCLUSION Berberine has a substantial effect in improving metabolic parameters and modulating the gut microbiota composition in T2DM rats.