Treatment of inflammatory bowel disease associated E. coli with ciprofloxacin and E. coli Nissle in the streptomycin-treated mouse intestine

Delivery of E. coli Nissle to the mouse gut by mucoadhesive microcontainers does not improve its competitive ability against strains linked to ulcerative colitis

For patients with ulcerative colitis (UC), administration of the probiotic E. coli Nissle (EcN) holds promise for alleviation of disease symptoms. The mechanisms are unclear, but it has been hypothesised that a capacity of the probiotic to outcompete potentially detrimental UC-associated E. coli strains plays an important role. However, this could previously not be confirmed in a mouse model of competition between EcN and two UC-associated strains, as reported by Petersen et al. 2011. In the present study, we re-evaluated the idea, hypothesising that delivery of EcN by a micro device dosing system (microcontainers), designed for delivery into the intestinal mucus, could support colonisation and confer a competition advantage compared to classical oral dosing. Six groups of mice were pre-colonised with one of two UC-associated E. coli strains followed by oral delivery of EcN, either in capsules containing microcontainers with freeze-dried EcN powder, capsules containing freeze-dried EcN powder, or as a fresh sucrose suspension. Co-colonisation between the probiotic and the disease-associated strains was observed regardless of dosing method, and no competition advantages linked to microcontainer delivery were identified within this setup. Other approaches are thus needed if the competitive capacity of EcN in the gut should be improved.

Antibacterial potential of ellagic acid and gallic acid against IBD bacterial isolates and cytotoxicity against colorectal cancer

Ellagic acid and Gallic acid are polyphenols which have shown beneficial effects in animal models of colitis. In the present study Ellagic acid and Gallic acid were evaluated for antibacterial potential against clinical IBD isolates. (HM95, HM233, HM251, HM615). Cytotoxicity was determined against human colorectal adenocarcinoma cells (Caco2, COLO.205, HT.29), whereas, cytocompatibility against normal rat intestinal epithelial (IEC-6) using MTT assay. Ellagic acid showed the lowest MIC and MBC value of 2.5 and 5 mg/mL respectively against HM251 and HM233. Gallic acid exhibited the lowest MIC and MBC value of 1.25 and 2.5 mg/mL respectively against HM251 and HM615. Cytotoxicity assay resulted in reduction of percent cell viability when tested at concentrations ranging from 400-12.5 µg/mL. The polyphenols presented a concentration-dependent deduction in percent cell viability after 48 h exposure It is likely that these polyphenols are good anti-colitic agents. However, further investigations are required.

Intestinal effect of the probiotic Escherichia coli strain Nissle 1917 and its OMV

Several investigations have been conducted during the past years to examine the correlation between dysbiosis and both intestinal and extra-intestinal diseases such as inflammatory bowel disease (IBD) and ulcerative colitis (UC). E. coli Nissle 1917 (EcN) is a nonpathogenic gram-negative strain utilized in numerous gastrointestinal issues, consisting of diarrhea, uncomplicated diverticular malady, IBD and specifically UC. Many investigations have been done to examine the capability of assertive bacteria, inclusive of commensal and probiotic strains to enhance IBD in clinical testing. Bacterial secreted factors have been investigated to detect the EcN agents that facilitate the regulation of tight junction. These agents candiffuse smoothly through the mucin layer before reaching intestinal epithelial cells. Outer membrane vesicles (OMVs) are known as intercellular communicasomes as they facilitate the distal transfer of active compounds between cells. A few investigations have detailed immune-modulatory attributes for EcN through various systems that could be liable for its clinical viability in IBD. Today, the function of gut microbiota extracellular vesicles in health and disease has become a focus of attention as they serve as vehicles for the transmission of microorganisms to distal tissues of many bacterial effectors.

Extraintestinal pathogenic Escherichia coli are associated with intestinal inflammation in patients with ulcerative colitis

E. coli of the phylogenetic group B2 harbouring Extra intestinal Pathogenic Escherichia coli (ExPEC) genes are frequently seen as colonizers of the intestine in patients with active ulcerative colitis (UC). In this study, we describe the influence of E. coli Nissle (EcN) B2 as add-on treatment to conventional therapies in patients with active UC. For this study one hundred active UC patients were randomized to ciprofloxacin or placebo for 1 week followed by EcN or placebo for 7 weeks. Stool samples were collected at weeks 0, 1, 8, 12, where E. coli were characterized and fecal calprotectin was measured. We showed that in the active UC patient group receiving Placebo/EcN, fewer patients reached remission, in comparison to the patient group receiving Placebo/placebo (p < 0.05). Active UC patients initially colonized with E. coli B2 had increased fecal calprotectin values and Colitis Activity Index scores in comparison to patients colonized with E. coli A and D (p < 0.05*). In conclusion, treatment of UC patients with E. coli Nissle (B2) does not promote clinical remission and active UC patients colonized with E. coli B2 have an increased intestinal inflammation.

Ciprofloxacin and probiotic Escherichia coli Nissle add-on treatment in active ulcerative colitis: a double-blind randomized placebo controlled clinical trial

BACKGROUND AND AIM

Ulcerative colitis (UC) is a chronic inflammatory bowel disease. The probiotic bacterium Escherichia coli Nissle 1917 (EcN) has been used to maintain and induce clinical remission in UC. Our aim was to test the effect of Ciprofloxacin and/or orally administered EcN as add-on to conventional therapies in patients with active UC.

PATIENTS AND METHODS

Our single center double-blinded randomized placebo controlled study included patients with a Colitis Activity Index (CAI) score of at least 6. Patients were randomized to Ciprofloxacin or placebo for 1week followed by EcN or placebo for 7weeks. All 4 treatments were given as add-on treatments.

RESULTS

One hundred subjects with active UC were recruited. In the per-protocol analysis we, surprisingly, found that in the group receiving placebo/EcN fewer patients, 54%, reached remission compared to the group receiving placebo/placebo, 89%, p<0.05. Among patients treated with Cipro/placebo and Cipro/EcN, 78% and 66% reached remission, respectively. Furthermore, the group receiving placebo/EcN had the largest number of withdrawals, 11 of 25 (44%), compared to 15 of 75 (20%) in any of the other groups, p<0.05. Indication of lack of mucosal healing was found in the group treated with placebo/Nissle, since only 4 (29%) of the 14 patients, who completed the study, reported no blood in stools at week 12 (p<0.02), compared to 63%, 67% and 65% in groups treated with Cipro/Nissle, Cipro/placebo and placebo/placebo, respectively.

CONCLUSIONS

Our data suggest that there is no benefit in the use of E. coli Nissle as an add-on treatment to conventional therapies for active ulcerative colitis. Furthermore, treatment with E. coli Nissle without a previous antibiotic cure resulted in fewer patients reaching clinical remission.

Intestinal microbiota: its role in digestive diseases

It is now well known that intestinal microbiota exerts not only several physiological functions, but has also been implied in the mechanisms of many conditions, both intestinal and extraintestinal. These advances, to the best of our knowledge, have been made possible by the development of new ways of studying gut flora. Metagenomics, the study of genetic material taken directly from environmental samples, avoiding individual culture, has become an excellent tool to study the human microbiota. Therefore, it has demonstrated an association between an altered intestinal microbiota and inflammatory bowel disease or irritable bowel syndrome, perhaps the most extensively studied conditions associated with this particular subject. However, microbiota has a potential role in the development of other diseases; their manifestations are not confined to the intestine only. In this article, an extensive updated review is conducted on the role intestinal microbiota has in health and in different diseases. Focus is made on the following conditions: inflammatory bowel disease, irritable bowel syndrome, celiac disease, hepatic encephalopathy, and obesity.