Diet effects on colonic health influence the efficacy of Bin1 mAb immunotherapy for ulcerative colitis.

Ulcerative colitis (UC) is an idiopathic disease of the large intestine linked to high fat-high protein diets, a dysbiotic microbiome, and a metabolome linked to diet and/or aberrant circadian rhythms associated with poor sleeping patterns. Understanding diet-affected factors that negatively influence colonic health may offer new insights into how to prevent UC and enhance the efficacy of UC immunotherapy. In this preclinical study, we found that standard or high fiber diets in mice positively influenced their colonic health, whereas a high fat-high protein diet negatively influenced colonic health, consistent with clinical findings. Animals fed a high fat/high protein diet experienced obesity and a reduced colon length, illustrating a phenotype we suggest calling peinosis [hunger-like-condition; Greek, peina: hunger; osis: condition], as marked by a lack of nutrient energy remaining in fecal pellets. Notably, a high fat/high protein diet also led to signs of muscle weakness that could not be explained fully by weight gain. In contrast, mice on a high fiber diet ranked highest compared to other diets in terms of colon length and lack of muscle weakness. That said, mice on a high fiber diet were more prone to UC and toxic responses to immunotherapy, consistent with clinical observations. Recent studies have suggested that a standard diet may be needed to support the efficacy of immunotherapeutic drugs used to prevent and treat UC. Here we observed that protection against UC by Bin1 mAb, a passive UC immunotherapy that acts by coordinately enforcing intestinal barrier function, protecting enteric neurons, and normalizing the microbiome, was associated with increased colonic levels of healthful short-chain fatty acids (SCFA), particularly butyric acid and propionic acid, which help enforce intestinal barrier function. This work offers a preclinical platform to investigate how diet affects UC immunotherapy and the potential of dietary SCFA supplements to enhance it. Further, it suggests that the beneficial effects of passive immunotherapy by Bin1 mAb in UC treatment may be mediated to some extent by promoting increased levels of healthful SCFA.

Bin1 targeted immunotherapy alters the status of the enteric neurons and the microbiome during ulcerative colitis treatment.

Ulcerative colitis (UC) is a common chronic disease of the large intestine. Current anti-inflammatory drugs prescribed to treat this disease have limited utility due to significant side-effects. Thus, immunotherapies for UC treatment are still sought. In the DSS mouse model of UC, we recently demonstrated that systemic administration of the Bin1 monoclonal antibody 99D (Bin1 mAb) developed in our laboratory was sufficient to reinforce intestinal barrier function and preserve an intact colonic mucosa, compared to control subjects which displayed severe mucosal lesions, high-level neutrophil and lymphocyte infiltration of mucosal and submucosal areas, and loss of crypts. A dysbiotic microbiome may lead to UC. We determined the effects of Bin1 mAb on the gut microbiome and colonic neurons and correlated the benefits of immunotherapeutic treatment. In the DSS model, we found that induction of UC was associated with disintegration of enteric neurons and elevated levels of glial cells, which translocated to the muscularis at distinct sites. Further, we characterized an altered gut microbiome in DSS treated mice associated with pathogenic proinflammatory characters. Both of these features of UC induction were normalized by Bin1 mAb treatment. With regard to microbiome changes, we observed in particular, increase in Enterobacteriaceae; whereas Firmicutes were eliminated by UC induction and Bin1 mAb treatment restored this phylum including the genus Lactobacillus. Overall, our findings suggest that the intestinal barrier function restored by Bin1 immunotherapy in the DSS model of UC is associated with an improvement in the gut microbiome and preservation of enteric neurons, contributing overall to a healthy intestinal tract.

Zinc and gastrointestinal disease.

This review is a current summary of the role that both zinc deficiency and zinc supplementation can play in the etiology and therapy of a wide range of gastrointestinal diseases. The recent literature describing zinc action on gastrointestinal epithelial tight junctions and epithelial barrier function is described. Zinc enhancement of gastrointestinal epithelial barrier function may figure prominently in its potential therapeutic action in several gastrointestinal diseases.

Drug delivery of zinc to Barrett's metaplasia by oral administration to Barrett's esophagus patients.

BACKGROUND: Delivery of a pharmacologically effective drug dosage to a target tissue is critical. Barrett's epithelia are a unique challenge for drug delivery of orally administered zinc due to rapid transit down the esophageal lumen, incomplete absorptive differentiation of these epithelia, and the use of proton-pump inhibitor drugs abrogating intestinal uptake of supplemental zinc. METHODS: Barrett's esophagus patients were administered oral zinc gluconate (26 mg zinc twice daily) for 14 days prior to biopsy procurement. Barrett's biopsies were analyzed for total zinc content by atomic absorption spectroscopy and by western immunoblot for cellular proteins known to be regulated by zinc. RESULTS: Cellular levels of both the Znt-1 transport protein and the alpha isoform of PKC were over 50% lower in the zinc treatment group. CONCLUSION: Oral zinc administration can result in effective delivery of zinc to Barrett's epithelia with resulting effects on intracellular signal transduction.

Transepithelial leak in Barrett's esophagus patients: the role of proton pump inhibitors.

AIM: To determine if the observed paracellular sucrose leak in Barrett's esophagus patients is due to their proton pump inhibitor (PPI) use. METHODS: The in vivo sucrose permeability test was administered to healthy controls, to Barrett's patients and to non-Barrett's patients on continuous PPI therapy. Degree of leak was tested for correlation with presence of Barrett's, use of PPIs, and length of Barrett's segment and duration of PPI use. RESULTS: Barrett's patients manifested a near 3-fold greater, upper gastrointestinal sucrose leak than healthy controls. A decrease of sucrose leak was observed in Barrett's patients who ceased PPI use for 7 d. Although initial introduction of PPI use (in a PPI-naïve population) results in dramatic increase in sucrose leak, long-term, continuous PPI use manifested a slow spontaneous decline in leak. The sucrose leak observed in Barrett's patients showed no correlation to the amount of Barrett's tissue present in the esophagus. CONCLUSION: Although future research is needed to determine the degree of paracellular leak in actual Barrett's mucosa, the relatively high degree of leak observed with in vivo sucrose permeability measurement of Barrett's patients reflects their PPI use and not their Barrett's tissue per se.

Proton Pump Inhibitors Interfere With Zinc Absorption and Zinc Body Stores.

BACKGROUND: Proton pump inhibitors (PPIs) cause a sharp elevation of gastro-duodenal luminal pH which in turn has resulted in reports of reduced absorption of magnesium and certain other nutrients. METHODS: Gastroesophageal reflux disease (GERD) patients on long-term PPI therapy (> 6 months) or healthy test subjects (not on any acid preventive or neutralizing medication) were administered oral doses of zinc gluconate (26.2 mg zinc, twice daily) for 14 days followed by 5 cc venous blood samples. Plasma was analyzed for total zinc content by atomic absorption spectrophotometry. Baseline plasma and red blood cell zinc levels were also measured in these two groups when not taking any zinc supplementation. RESULTS: Plasma zinc levels of healthy controls increased by 126% during the period of zinc supplementation compared to only a 37% increase for individuals on long-term PPI therapy. On their normal diet (with no zinc supplementation), PPI-users had a 28% lower plasma zinc level than healthy controls (P < 0.005). CONCLUSIONS: PPI use dramatically reduces supplemental zinc uptake and can result in decreased zinc body stores. Certain individuals on long-term PPI therapy, such as infants being treated for colic, may be at risk for decreased systemic levels of trace metals needed for developmental, regenerative and immunological requirements.

Overuse of stress ulcer prophylaxis in the critical care setting and beyond.

BACKGROUND: Patients admitted to the intensive care unit (ICU) are susceptible to stress ulcers. We hypothesize that despite recommendations, stress ulcer prophylaxis (SUP) is still overused in the ICU and often continued after resolution of risk factors for bleeding. METHODS: We retrospectively studied all ICU admissions for 4 months. Risk factors for stress ulcer bleeding were collected. Patients were categorized into 4 groups: (1) >or=1 major risk factor; (2) >or=1 minor risk factors; (3) no risk factors; (4) preadmission use of acid-suppressive medication. The rate of SUP was calculated by group during ICU stay, on transfer from the ICU, and at hospital discharge. RESULTS: Two hundred ten patients were studied. Of all the ICU admissions, 87.1% received SUP. Among patients with no risk factors, 68.1% were placed on prophylaxis on ICU admission; 60.4% continued on treatment upon transfer from the ICU; 31.0% were discharged home on an agent without a new indication. CONCLUSIONS: Although judicious use of SUP in high-risk patients can decrease the incidence of gastrointestinal bleeding, inappropriate use may increase drug reactions, unnecessary hospital costs, and personal monetary burden. Our findings argue for improvement measures to reduce initial inpatient overuse of SUP and to prompt discontinuation before hospital discharge.

Mallory-Weiss tear diagnosed in the immediate postpartum period: a case report.

BACKGROUND: Mallory-Weiss tears occur rarely during pregnancy, labour and delivery, and the puerperium, despite the increased frequency of retching and vomiting. CASE: We describe a Mallory-Weiss syndrome diagnosed during the immediate postpartum period in a 34-year-old primigravida. The syndrome initially manifested as lower gastrointestinal bleeding and melena. CONCLUSION: If unrecognized, this complication may lead to life-threatening internal bleeding. It is important to look for an occult bleeding source with such a presentation, and prompt intervention is essential.

Bacteremia due to clostridium difficile: case report and review of the literature.

OBJECTIVE: The purpose of this study is to report a case of C. difficile bacteremia in a Crohn's disease patient and to review the literature on previously reported cases. METHODS: Searches of MEDLINE and PubMed databases were made. RESULTS: We report the first case of C. difficile bacteremia in a Crohn's disease patient. There are 15 other reported cases of C. difficile bacteremia reported in the literature. We found that the majority of patients (10 of 15 patients) had polymicrobial bacteremia and that the overall mortality rate is significant, with 6 of 15 reported patients dying. CONCLUSION: In conclusion, we find that C. difficile bacteremia is associated with a significant mortality rate and it would seem prudent to consider aggressive antibiotic therapy.

Absence of Na+/sugar cotransport activity in Barrett's metaplasia.

AIM: To evaluate the presence of Na+-dependent, active, sugar transport in Barrett's epithelia as an intestinal biomarker, based on the well-documented, morphological intestinal phenotype of Barrett's esophagus (BE). METHODS: We examined uptake of the nonmeta-bolizable glucose analogue, alpha-methyl-D-glucoside (AMG), a substrate for the entire sodium glucose cotransporter (SGLT) family of transport proteins. During upper endoscopy, patients with BE or with uncomplicated gastroesophageal reflux disease (GERD) allowed for duodenal, gastric fundic, and esophageal mucosal biopsies to be taken. Biopsies were incubated in bicarbonate-buffered saline (KRB) containing 0.1 mmol/L 14C-AMG for 60 min at 20 centigrade. Characterized by abundant SGLT, duodenum served as a positive control while gastric fundus and normal esophagus, known to lack SGLT, served as negative controls. RESULTS: Duodenal biopsies accumulated 249.84+/-35.49 (SEM) picomoles AMG/microg DNA (n=12), gastric fundus biopsies 36.20+/-6.62 (n=12), normal esophagus 12.10+/-0.59 (n=3) and Barrett's metaplasia 29.79+/-5.77 (n=8). There was a statistical difference (P<0.01) between biopsies from duodenum and each other biopsy site but there was no statistically significant difference between normal esophagus and BE biopsies. 0.5 mmol/L phlorizin (PZ) inhibited AMG uptake into duodenal mucosa by over 89%, but had no significant effect on AMG uptake into gastric fundus, normal esophagus, or Barrett's tissue. In the absence of Na+ (all Na+ salts replaced by Li+ salts), AMG uptake in duodenum was decreased by over 90%, while uptake into gastric, esophageal or Barrett's tissue was statistically unaffected. CONCLUSION: Despite the intestinal enterocyte phenotype of BE, Na+-dependent, sugar transport activity is not present in these cells.