Relationships of Intestinal Lactase and the Small Intestinal Microbiome with Symptoms of Lactose Intolerance and Intake in Adults.

BACKGROUND: Approximately two-thirds of adults are genetically predisposed to decreased lactase activity after weaning, putting them at risk of lactose intolerance. However, symptoms are a poor marker of lactose maldigestion. AIMS: We assessed association between self-reported lactose intolerance and intestinal lactase, lactose intake, and the small intestinal microbiome. METHODS: Patients 18-75 years presenting for upper endoscopy were recruited prospectively. Observational study participants completed a lactose intolerance symptom questionnaire and reported lactose intake. Post-bulbar biopsies were obtained to measure lactase activity and assess the small intestinal mucosal microbiome. We compared intestinal lactase between patients with and without lactose intolerance. We assessed associations between lactose intolerance symptoms and lactase and lactose intake. We examined associations of small bowel microbial composition with self-reported lactose intolerance and symptoms. RESULTS: Among 34 patients, 23 (68%) reported lactose intolerance. Those with lactose intolerance had higher total symptom scores, more frequent bowel urgency, and more bowel movements after consuming dairy. The proportion of individuals with abnormal lactase activity did not differ by lactose intolerance status. Median lactase levels were correlated with total lactose intolerance symptom scores (p = 0.038) and frequency of bowel urgency (p = 0.012). Daily lactose intake did not differ between groups. In 19 patients, we observed significant associations of small intestinal microbiome beta diversity with stool consistency after consuming dairy (p = 0.03). CONCLUSIONS: Intestinal lactase is associated with lactose intolerance symptoms and bowel urgency in adults but does not distinguish the clinical phenotype entirely. Studying other contributing factors (microbiota, diet) may further clarify the pathophysiology of lactose intolerance.

Optical diagnosis of colorectal polyps using novel blue light imaging classification among trainee endoscopists.

BACKGROUND: Blue light imaging (BLI) has been shown to improve the characterization of colorectal polyps among the endoscopy experts. We aimed to determine if this technology could be taught to endoscopy trainees while maintaining high accuracy and interobserver agreement. METHODS: Twenty-one gastroenterology trainees (fellows) from two academic institutions participated in this prospective study. Each trainee completed a web-based learning comprising four modules: pre-test, didactic videos explaining the BLI Adenoma Serrated International Classification (BASIC), interactive examples, and post-test assessment. The pre- and post-test modules consisted of reviewing video images of colon polyps in high definition white light imaging and BLI and then applying the BASIC classification to determine if the polyps were likely to be adenomatous. Confidence in adenoma identification (rated '1' to '5'), accuracy in polyp (adenoma vs. non-adenoma) identification, and agreement in characterization per BASIC criteria were derived. RESULTS: Trainee accuracy in the adenoma diagnosis improved from 74.7% (pre-test) to 85.4% (post-test) (P < 0.01). There was a trend towards higher accuracy in polyp characterization with subsequent years of training (1st year fellows 77.4%, 2nd year 88.5%, and final year 94.0%) with consistent improvements after the e-learning across years of trainees. Overall, trainees were able to identify adenoma with a high sensitivity of 86.9%, specificity 83.9%, positive predictive value of 84.4%, and negative predictive value of 86.5%. However, their interobserver agreement in adenoma diagnosis was moderate (k = 0.52). CONCLUSION: The novel BLI classification can be easily taught to gastroenterology trainees using an online module and accuracy improves with years of training reaching >90% for colorectal polyp characterization.

Nuts and Bolts of Fecal Microbiota Transplantation.

Clostridium difficile infection (CDI) has become the leading cause of nosocomial infection in the United States with significant risk of both morbidity and mortality. While antimicrobial therapy forms the basis of treatment, there are several clinical scenarios in which antimicrobial therapy alone is insufficient. Evidence continues to show the safety and efficacy fecal microbiota transplantation (FMT) in recurrent and severe CDI. This review will outline FMT efficacy, safety, and indications and present practical advice for clinicians interested in best practices around delivery of FMT.

Early Infections and the Risk of Irritable Bowel Syndrome: A Case-Control Study.

GOALS: The goal of this study is to evaluate the association between early life infections and subsequent adult onset irritable bowel syndrome (IBS). BACKGROUND: Infections during adulthood are a known risk factor for adult-onset IBS. This investigation examined the role of childhood infections and infection risk factors in the development of IBS symptoms. STUDY: In total, 1010 subjects (509 outpatients with IBS, 501 matched controls) were mailed questionnaires regarding early-life infections during infancy (0 to 12 mo), toddler years (1 to 3 y), and child years (4 to 18 y). Comparisons between cases and controls were performed using logistic regression adjusting for age, gender, and somatization score. RESULTS: Around 648 (64.2%) subjects responded. The median age was 51.3 years (range, 18.0 to 70.7 y) and 535 (83%) were female. Childhood (below 18 y) infections were common in cases and controls (98% vs. 98%; P=0.465), with no differences between cases and controls during infant, toddler, and child-age periods. For gastrointestinal infections experienced below 18 years, no differences were observed by infection type (bacterial, viral, or parasitic) or age group. Cases were more likely to report bronchitis by age 18 [43% vs. 25%; P=0.003; odds ratio, 1.73 (1.20-2.51)], but not other common infections. Regular antibiotic exposure was greater amongst cases (43%) than controls (30%) [P=0.09; odds ratio, 1.37 (0.96-1.96)]. The association between bronchitis and IBS case status remained significant after adjusting for antibiotic use (P=0.01). CONCLUSIONS: Greater early childhood gastrointestinal infections rates were not observed in adult individuals with IBS compared with adult controls. The study does not support a statistically significant link between early life infections and IBS aside from bronchitis.

An acute care approach to functional abdominal pain.

Functional abdominal pain disorders are commonly seen in the acute care setting and can be a source of frustration for patients and providers given their inherent chronic nature. However, an understanding of both the general approach to these disorders and the approach to specific common subtypes can help alleviate this frustration and lead to both short-term and long-term therapeutic success. This article describes the pathophysiology of these disorders and outlines a diagnostic and therapeutic approach to commonly seen functional abdominal pain disorders in adults.

Not FIT for Use: Fecal Immunochemical Testing in the Inpatient and Emergency Settings.

BACKGROUND: Fecal immunochemical testing (FIT) is widely used for colorectal cancer screening, its only indication. Its effect on clinical decision-making beyond screening is unknown. We studied the use of FIT in emergency and inpatient settings and its impact on patient care. METHODS: Using electronic medical records, we reviewed all non-ambulatory FITs performed from November 2017 to October 2019 at a tertiary care community hospital. We collected data on demographics, indications, gastroenterology consultations, and endoscopic procedures. Multivariate logistic regression was performed to determine the effect of FIT on gastroenterology consultation and endoscopy. RESULTS: We identified 550 patients with at least 1 FIT test. Only 3 FITs (0.5%) were performed for colorectal cancer screening. FITs were primarily ordered from the emergency department (45.3%) or inpatient hospital floor (42.2%). Anemia (44.0%), followed by gastrointestinal bleeding (40.9%), were the most common indications. FIT was positive in 253 patients (46.0%), and gastroenterology consultation was obtained for 47.4% (n = 120), compared with 14.5% (n = 43) of the 297 FIT-negative patients (odds ratio 3.28; 95% confidence interval, 2.23-4.82, P < .0001). A potential bleeding source was identified in 80% of patients with reported or witnessed overt gastrointestinal bleeding, a similar proportion (80.7%; P = .92) to patients who were FIT positive with overt gastrointestinal bleeding. Multivariate analysis showed that melena, hematemesis, and a positive FIT were associated with gastroenterology consultation (all P < .05), while only melena (odds ratio 3.34; 95% confidence interval, 1.48-7.54) was associated with endoscopy. CONCLUSIONS: Nearly all emergency department and inpatient FIT use was inappropriate. FIT resulted in more gastroenterology consultation but was not independently associated with inpatient endoscopy.

Lactose Intolerance: A Concise Review to Skim the Surface.

Lactose intolerance is a common but poorly understood cause of gastrointestinal symptoms. Contrary to popular belief, there is much more to its diagnosis beyond symptoms with exposure and management beyond milk- and dairy-product avoidance. In this article, we review definitions, genetic basis, pathogenesis, clinical signs, as well as diagnostic and management strategies.

Fulminant Clostridium difficile Infection Cured by Fecal Microbiota Transplantation in a Bone Marrow Transplant Recipient With Critical Neutropenia.

Clostridium difficile infection is the most prevalent health care-associated infection. Treatment relies on antimicrobial therapy with mounting evidence supporting fecal microbiota transplant (FMT) in refractory cases. Cohort studies have documented the safety of FMT in immunocompromised patients. However, the safety of FMT in patients with critically low (<500/µL) absolute neutrophil count is unknown. Currently, in severely immunocompromised bone marrow or solid organ transplant recipients, FMT is delayed until normalization of absolute neutrophil count. We present a patient with absolute neutropenia in whom sequential FMTs were safely and successfully administered, resulting in cure of fulminant C. difficile infection.

Ischemic Cholangiopathy 11 Years after Liver Transplantation from Asymptomatic Chronic Hepatic Artery Thrombosis.

Hepatic artery thrombosis is a concerning complication of orthotopic liver transplantation, and it most often occurs early in the posttransplant period. However, on rare occasions it can occur at a time remote from transplant. We present a case of ischemic cholangiopathy complicated by stricture and anastomotic bile leak from chronic hepatic artery thrombosis that occurred 11 years after the transplant. The initial biliary stenting helped with the resolution of the leak but she was found to have stones, sludge and copious pus at the time of stent exchange. Hepatic arteriography demonstrated complete occlusion of the transplant hepatic artery with periportal collaterals reconstituting intrahepatic hepatic arterial branches. The patient was subsequently referred for repeat liver transplantation.

Cytomegalovirus and the Seemingly Immunocompetent Host: A Case of a Perforating Gastric Ulcer.

Cytomegalovirus (CMV) infection of the gastrointestinal tract has a variety of presentations. We present a case of gastric perforation, which is a relatively infrequent presentation of CMV infection. If the cause of gastric perforation is not readily apparent, testing for CMV should be considered. If CMV workup is positive, an evaluation for immunocompromise is prudent as CMV infections are more common in immunocompromised individuals.

Small Intestinal Bacterial Overgrowth: A Primary Care Review.

Gastrointestinal symptoms are commonly seen in the primary care setting.1 These patient presentations can be nonspecific, leading to a broad differential diagnosis. Small intestinal bacterial overgrowth is a clinical entity that can present with many of these nonspecific gastrointestinal symptoms. The recent interest in the microbiome by those in the medical and lay communities has made this syndrome all the more relevant. This review gives the primary care provider an up-to-date understanding of the etiology, risk factors and predisposing factors, presentation, diagnostic testing, and management of small intestinal bacterial overgrowth.