Maitreyi Raman

Fecal Microbiome and Volatile Organic Compound Metabolome in Obese Humans With Nonalcoholic Fatty Liver Disease

BACKGROUND & AIMS The histopathology of nonalcoholic fatty liver disease (NAFLD) is similar to that of alcoholic liver disease. Colonic bacteria are a source of many metabolic products, including ethanol and other volatile organic compounds (VOC) that may have toxic effects on the human host after intestinal absorption and delivery to the liver via the portal vein. Recent data suggest that the composition of the gut microbiota in obese human beings is different from that of healthy-weight individuals. The aim of this study was to compare the colonic microbiome and VOC metabolome of obese NAFLD patients (n = 30) with healthy controls (n = 30). METHODS Multitag pyrosequencing was used to characterize the fecal microbiota. Fecal VOC profiles were measured by gas chromatography-mass spectrometry. RESULTS There were statistically significant differences in liver biochemistry and metabolic parameters in NAFLD. Deep sequencing of the fecal microbiome revealed over-representation of Lactobacillus species and selected members of phylum Firmicutes (Lachnospiraceae; genera, Dorea, Robinsoniella, and Roseburia) in NAFLD patients, which was statistically significant. One member of phylum Firmicutes was under-represented significantly in the fecal microbiome of NAFLD patients (Ruminococcaceae; genus, Oscillibacter). Fecal VOC profiles of the 2 patient groups were different, with a significant increase in fecal ester compounds observed in NAFLD patients. CONCLUSIONS A significant increase in fecal ester VOC is associated with compositional shifts in the microbiome of obese NAFLD patients. These novel bacterial metabolomic and metagenomic factors are implicated in the etiology and complications of obesity.

Prevalence and Mechanisms of Malnutrition in Patients With Advanced Liver Disease, and Nutrition Management Strategies

Malnutrition is prevalent among cirrhotic patients and is an important prognostic factor. Etiologic factors include hypermetabolism, malabsorption, altered nutrient metabolism, and anorexia. It is a challenge to manage nutrition in cirrhotic patients because of alterations to metabolic and storage functions of the liver; use of traditional assessment tools, such as anthropometric and biometric measures, is difficult because of complications such as ascites and inflammation. In addition to meeting macro- and micronutrient requirements, the composition and timing of supplements have been proposed to affect efficacy of nutrition support. Studies have indicated that branched chain aromatic acid can be given as therapeutic nutrients, and that probiotics and nocturnal feeding improve patient outcomes.

The potential role of prebiotic fibre for treatment and management of non-alcoholic fatty liver disease and associated obesity and insulin resistance.

Non‐alcoholic fatty liver disease (NAFLD) and the more severe non‐alcoholic steatohepatitis (NASH) represent a spectrum of diseases involving hepatic fat accumulation and histological features essentially identical to alcoholic liver disease; however, they occur in the absence of excessive alcohol intake. They typically arise in conjunction with one or more features of the metabolic syndrome. Lifestyle mediated weight loss remains the primary mode of therapy for NAFLD and NASH, but this is often ineffective and adjunctive medical and surgical treatments are presently lacking. Prebiotic fibres are a group of non‐digestible carbohydrates that modulate the human microbiota in a manner that is advantageous to host health. Rodent studies suggest that dietary supplementation with prebiotic fibres positively impacts NAFLD by modifying the gut microbiota, reducing body fat, and improving glucoregulation. Future research should focus on placebo‐controlled, human, clinical trials using histological endpoints to address the effects of prebiotics on NAFLD and NASH. The aim of this review is to summarize current knowledge about prebiotics as an emerging therapeutic target for NAFLD.

Obesity: A review of pathogenesis and management strategies

The prevalence of obesity in the developed world is increasing. Approximately 23% of adult Canadians (5.5 million people) are obese. Obesity is associated with an increased risk of developing several comorbid diseases, ranging from cardiovascular diseases to cholelithiasis and nonalcoholic fatty liver disease. The etiology of obesity is multifactorial, involving a complex interaction among genetics, hormones and the environment. The available evidence and recommendations for nonpharmacological management of obesity, including dietary therapy, physical activity and behavioural therapy, in addition to pharmacotherapy are discussed. A brief discussion on endoscopic and surgical procedures is undertaken. Several antiobesity treatment options are available and may be indicated in appropriate situations. Selecting obesity therapy may be guided by body mass index measurements, comorbid illnesses and patient preference.

Vitamin D and gastrointestinal diseases: inflammatory bowel disease and colorectal cancer

Over the past 5 years, there has been a rapid resurgence of interest in vitamin D outside of its traditional role in metabolic bone disease. Some nontraditional roles ascribed to vitamin D include anti-inflammatory and immune-modulating effects. These effects have led to possible implications in the pathophysiology of immune-mediated diseases including multiple sclerosis and inflammatory bowel disease (IBD). In addition, vitamin D insufficiency has been linked to higher rates of cancers including colon, prostate and breast cancers. Given these diverse associations of vitamin D and disease states, this review describes recent advances with regard to vitamin D and gastrointestinal diseases, in particular IBD and colorectal cancer.

Teaching in small portions dispersed over time enhances long-term knowledge retention

Background: A primary goal of education is to promote long-term knowledge storage and retrieval. Objective: A prospective interventional study design was used to investigate our research question: Does a dispersed curriculum promote better short- and long-term retention over a massed course? Methods: Participants included 20 gastroenterology residents from the University of Calgary (N = 10) and University of Toronto (N = 10). Participants completed a baseline test of nutrition knowledge. The nutrition course was imparted to University of Calgary residents for 4 h occurring 1 h weekly over 4 consecutive weeks: dispersed delivery (DD). At the University of Toronto the course was taught in one 4h academic half-day: massed delivery (MD). Post-curriculum tests were administered at 1 week and 3 months to assess knowledge retention. Results: The baseline scores were 46.39 ± 6.14% and 53.75 ± 10.69% in the DD and MD groups, respectively. The 1 week post-test scores for the DD and MD groups were 81.67 ± 8.57%, p < 0.001 and 78.75 ± 4.43, p < 0.001 which was significantly higher than baseline. The 3-month score was significantly higher in the DD group, but not in the MD group (65.28 ± 9.88%, p = 0.02 vs. 58.93 ± 12.06%, p = 0.18). The absolute pre-test to 1-week post-test difference was significantly higher at 35.28 ± 7.65% among participants in the DD group compared to 25.0 ± 11.80% in the MD group, p = 0.048. Similarly, the absolute pre-test to 3-month post-test difference was significantly higher at 18.9 ± 6.7% among the participants in the DD group, compared to 6.8 ± 11.8% in the MD group, p = 0.021. Conclusions: Long-term nutrition knowledge is improved with DD compared with MD.

Parenteral nutrition-associated hyperglycemia in noncritically ill inpatients is associated with higher mortality

BACKGROUND Hyperglycemia is a marker of poor clinical outcomes in studies evaluating hospitalized critically ill patients. OBJECTIVES To identify whether glycemic control is associated with health outcomes including acute coronary events, renal failure, infection, hospital length of stay, intensive care unit (ICU) admission, sepsis and mortality in noncritically ill patients administered parenteral nutrition (PN), and to compare the current standard of care for glucose monitoring at the Foothills Medical Centre (Calgary, Alberta) with the 2009 American Society of Parenteral and Enteral Nutrition guidelines. METHODS A retrospective chart review of 100 adult (18 years of age or older) non-ICU inpatients who received PN for seven days or longer at the Foothills Medical Centre was conducted. RESULTS Seventeen patients (17%) had a mean blood glucose level of 10.0 mmol/L or greater. PN patients with a mean blood glucose level of 10 mmol/L or greater had a higher rate of mortality than patients with a mean blood glucose level of less than 10 mmol/L (OR 7.22; 95% CI 1.08 to 48.29; P=0.042). Hyperglycemia was independently and significantly associated with mortality when adjusted for age and sex. Acute coronary events, renal failure, infection, hospital length of stay, ventilator use and ICU admissions were not associated with hyperglycemia. Only one-half of those with hyperglycemia, and none of the patients in the euglycemic group, received adequate glucose monitoring during the first two days of PN. CONCLUSION Hyperglycemia in noncritically ill inpatients receiving PN was found to be a risk factor for increased mortality.

How much do gastroenterology fellows know about nutrition

Background Many people are afflicted with chronic diseases, in which nutrition plays a key role. The need for greater nutrition training among physicians, particularly gastroenterologists, is becoming increasingly evident. Objectives To determine the nutritional knowledge and perceived nutrition knowledge of gastroenterology fellows. Methods Thirty-two gastrointestinal (GI) fellows currently enrolled in a GI fellowship program completed a needs assessment evaluating perceived nutrition knowledge and interest in the areas of nutrition support, assessment, obesity, micro/macronutrients, and nutrition in GI diseases. Additionally, an examination evaluating nutrition knowledge specific to gastroenterology fellows was administered. Results Thirty-two GI fellows completed the needs assessment. Cronbach α of the needs assessment instrument was 0.72, indicating satisfactory internal consistency reliability. GI fellows perceived themselves to have the least knowledge in obesity and micro/macronutrients. They indicated a perceived greater knowledge base in nutrition assessment. The mean total test score was 50.04% (SD=7.84%). Fellows had the highest score in the subscale of nutrition assessment (80.64%; SD=19.05%), which was significantly higher than scores obtained in nutrition support (49.45%; SD=11.98%; P<0.05), micro/macronutrients (37.84%; SD=16.94%; P<0.05), obesity (40.11%; SD=20.00%; P<0.05), and nutrition in GI diseases (65.05%; SD=22.09%; P<0.05). A backward linear regression including hours of nutrition education received during GI fellowship, hours of nutrition education received during medical school, and year of GI fellowship accounted for 22.7% of the variance in test performance (multiple R=0.477). Conclusions Gastroenterology fellows think their knowledge of nutrition is suboptimal; objective evaluation of nutrition knowledge in this cohort confirmed this belief. A formal component of nutrition education could be developed in the context of GI fellowship education and continuing medical education as necessary.

A Practical Approach to Nutritional Screening and Assessment in Cirrhosis.

Malnutrition is one of the most common complications of cirrhosis, associated with an increased risk of morbidity and mortality. As a potentially modifiable condition, it is of particular importance to identify malnourished patients so that nutritional therapy can be instituted. Nutrition screening and assessment are infrequently performed in patients with cirrhosis. The reasons for this are multifactorial, including the absence of a validated “rapid” screening tool, multiple definitions of what constitutes malnutrition, and challenges with interpreting body composition and laboratory results in the setting of volume overload and liver dysfunction. This article summarizes the clinically relevant evidence and presents key issues, tools, and clinical options that are applicable to patients with cirrhosis. The definition, etiology, and clinically relevant outcomes associated with malnutrition are reviewed. Rapid nutritional screening is differentiated from more detailed nutritional assessment. Nutritional assessment in special populations, including women and the obese, and the role of inflammation are discussed. Multicenter studies using a common nutritional screening/assessment strategy are the next steps to fast‐track adoption and implementation of nutrition‐related evaluations into routine clinical practice. (Hepatology 2017;65:1044‐1057).

Cognitive load imposed by knobology may adversely affect learners' perception of utility in using ultrasonography to learn physical examination skills, but not anatomy

Ultrasonography is increasingly used for teaching anatomy and physical examination skills but its effect on cognitive load is unknown. This study aimed to determine ultrasounds perceived utility for learning, and to investigate the effect of cognitive load on its perceived utility. Consenting first‐year medical students (n = 137) completed ultrasound training that includes a didactic component and four ultrasound‐guided anatomy and physical examination teaching sessions. Learners then completed a survey on comfort with physical examination techniques (three items; alpha = 0.77), perceived utility of ultrasound in learning (two items; alpha = 0.89), and cognitive load on ultrasound use [measured with a validated nine‐point scale (10 items; alpha = 0.88)]. Learners found ultrasound useful for learning for both anatomy and physical examination (mean 4.2 ± 0.9 and 4.4 ± 0.8, respectively; where 1 = very useless and 5 = very useful). Principal components analysis on the cognitive load survey revealed two factors, “image interpretation” and “basic knobology,” which accounted for 60.3% of total variance. Weighted factor scores were not associated with perceived utility in learning anatomy (beta = 0.01, P = 0.62 for “image interpretation” and beta = −0.04, P = 0.33 for “basic knobology”). However, factor score on “knobology” was inversely associated with perceived utility for learning physical examination (beta = −0.06; P = 0.03). While a basic introduction to ultrasound may suffice for teaching anatomy, more training may be required for teaching physical examination. Prior to teaching physical examination skills with ultrasonography, we recommend ensuring that learners have sufficient knobology skills. Anat Sci Educ 8: 197–204.