Bile composition in inflammatory bowel disease: ileal disease and colectomy, but not colitis, induce lithogenic bile

Use and Misuse of Parenteral Nutrition in Patients with Inflammatory Bowel Disease

Malnutrition is a very common and often underrecognized condition among patients with inflammatory bowel diseases (IBD). This is most commonly due to increased nutritional requirements and gastrointestinal losses, along with reduced oral intake. Screening for malnutrition is an essential component of managing both inpatients and outpatients with IBD. Although enteral nutrition is the preferred route of supplementation, parenteral nutrition (PN) remains an important strategy and should be considered in certain situations, such as cases with short-bowel syndrome, high-output intestinal fistula, prolonged ileus, or small-bowel obstruction. Appropriate use of PN is critical in order to prevent associated complications. This review addresses the common indications for use of PN, the composition of PN, and the possible complications encountered with PN use, as well as scenarios of inappropriate PN use among patients with IBD. A clinical management algorithm for utilizing PN among patients with IBD is proposed in this review.

Update on the Molecular Mechanisms Underlying the Effect of Cholecystokinin and Cholecystokinin-1 Receptor on the Formation of Cholesterol Gallstones

Cholecystokinin (CCK) is an important neuro-intestinal peptide hormone produced by the enteroendocrine I-cells in the upper part of small intestine. Protein- and fat-enriched food plays an important role in triggering CCK secretion from the intestine. Carbohydrates stimulate only small amounts of CCK release. The CCK-1 receptor (CCK-1R) is largely localized in the gallbladder, sphincter of Oddi, pancreas, small intestine, gastric mucosa, and pyloric sphincter, where it is responsible for CCK to regulate multiple digestive processes including gallbladder contraction, pancreatic secretion, small intestinal transit, and gastric emptying. Accumulated evidence clearly demonstrates that CCK regulates gallbladder and small intestinal motility through CCK-1R signaling cascade and the effect of CCK-1R on small intestinal transit is a physiological response for regulating intestinal cholesterol absorption. Disruption of the Cck or the Cck-1r gene in mice significantly increases the formation of cholesterol gallstones by disrupting gallbladder emptying and biliary cholesterol metabolism, as well as promoting intestinal absorption of cholesterol. Abnormalities in gallbladder motility function in response to exogenously administered CCK are found primarily in patients with cholesterol gallstones. Patients with pigment gallstones display an intermediate degree of gallbladder motility defect without gallbladder inflammation and enlarged fasting gallbladder. Dysfunctional gallbladder contractility has been found under several conditions such as pregnancy, obesity, diabetes, celiac disease, and total parenteral nutrition although gallstones are not observed. The gallbladder-specific CCK-1R-selective agonist may lead to an efficacious novel way for preventing gallstone formation by promoting gallbladder emptying, particularly for pregnant women and subjects with dysfunctional gallbladder motility function such as celiac patients, as well as patients with total parenteral nutrition.

Other Surgeries in Patients with Inflammatory Bowel Disease

Patients with inflammatory bowel disease (IBD) will often require abdominal surgical intervention for indications not directly related to their IBD. Because these patients often have a history of multiple previous abdominal operations and/or ostomies, they are at increased risk for incisional and parastomal hernias. They may also have develop symptomatic cholelithiasis, chronic pain, or desmoid disease. All of these potentially surgical issues may require special consideration in the IBD population.

Cholelithiasis and Related Morbidity in Chronic Intestinal Failure: a Longitudinal Cohort Study from a National Specialized Centre

BACKGROUND

Short-term studies have shown that patients with type III intestinal failure often develop gallstones and have recommended prophylactic cholecystectomy. In this retrospective cohort study, we aimed to define the incidence and clinical consequences of cholelithiasis over an extended time period, in order to refine the role of prophylactic cholecystectomy in type III intestinal failure.

METHODS

Data were retrospectively collected from a prospectively maintained audit. Patients with intestinal failure for 5 years or more were included. Kaplan-Meier analysis was used to estimate cumulative incidence over time. Predictors of cholelithiasis were evaluated by Cox regression.

RESULTS

Between 1 January 1983 and 1 December 2008, 81 patients were commenced on parenteral support lasting 5 years or more. Of 63 patients with no pre-existing gallstones on imaging, 17 (27%) developed gallstones during a median observation period of 133 months. On Kaplan-Meier analysis, the incidence at 10 years was 21%; at 20 years, 38%; and at 30 years, 47%. Thirteen of the 17 had symptoms and ten required surgical and/or endoscopic intervention. Increased weekly calorific content (P 0.003) and the provision of parenteral lipids (P 0.003) were predictors of cholelithiasis on univariable Cox regression.

CONCLUSION

Many patients with long-term intestinal failure develop gallstones over time, with a 20-year incidence of 38%. The majority of those have symptoms or complications and require intervention. Therefore, prophylactic en-passant cholecystectomy is justified when gallstones are present in type III intestinal failure, supporting routine pre-operative imaging of the gallbladder prior to abdominal surgery.

Cholecystectomy Risk in Crohn's Disease Patients After Ileal Resection: a Long-term Nationwide Cohort Study

BACKGROUND

The risk of gallstone disease necessitating cholecystectomy after ileal resection (IR) in Crohn's disease (CD) patients is not well established. We studied the incidence, cumulative and relative risk of cholecystectomy after IR in CD patients, and associated risk factors.

METHODS

CD patients with a first IR between 1991 and 2015 were identified in PALGA, a nationwide pathology database in the Netherlands. Details on subsequent cholecystectomy and IR were recorded. Yearly cholecystectomy rates from the general Dutch population were used as a reference.

RESULTS

A cohort of 8302 (3466 (41.7%) males) CD patients after IR was identified. During the 11.9 (IQR 6.3-18.0) years median follow-up, the post-IR incidence rate of cholecystectomy was 5.2 (95% CI 3.5-6.4)/1000 persons/year. The cumulative incidence was 0.5% at 1 year, 2.4% at 5 years, 4.6% at 10 years, and 10.3% after 20 years. In multivariable analyses, female sex (HR 1.9, CI 1.5-2.3), a later calendar year of first IR (HR_{/5-year increase}, HR 1.27, CI 1.18-1.35), and ileal re-resection (time-dependent HR 1.37, CI 1.06-1.77) were associated with cholecystectomy. In the last decade, cholecystectomy rates increased and were higher in our postoperative CD population than in the general population (relative incidence ratio 3.13 (CI 2.29-4.28; p < 0.0001) in 2015).

CONCLUSIONS

Although higher in females, increasing in recent years, and higher than in the general population, the overall risk of cholecystectomy in CD patients following IR is low and routine prophylactic measures seem unwarranted.

Faecalibacterium prausnitzii: from microbiology to diagnostics and prognostics

There is an increasing interest in Faecalibacterium prausnitzii, one of the most abundant bacterial species found in the gut, given its potentially important role in promoting gut health. Although some studies have phenotypically characterized strains of this species, it remains a challenge to determine which factors have a key role in maintaining the abundance of this bacterium in the gut. Besides, phylogenetic analysis has shown that at least two different F. prausnitzii phylogroups can be found within this species and their distribution is different between healthy subjects and patients with gut disorders. It also remains unknown whether or not there are other phylogroups within this species, and also if other Faecalibacterium species exist. Finally, many studies have shown that F. prausnitzii abundance is reduced in different intestinal disorders. It has been proposed that F. prausnitzii monitoring may therefore serve as biomarker to assist in gut diseases diagnostics. In this mini-review, we aim to serve as an overview of F. prausnitzii phylogeny, ecophysiology and diversity. In addition, strategies to modulate the abundance of F. prausnitzii in the gut as well as its application as a biomarker for diagnostics and prognostics of gut diseases are discussed. This species may be a useful potential biomarker to assist in ulcerative colitis and Crohn's disease discrimination.

Increased Risk of Gallstone Disease Following Colectomy for Ulcerative Colitis

OBJECTIVES

Biochemical studies suggest that patients who have had a colectomy or restorative proctocolectomy with ileal pouch-anal anastomosis (IPAA) are at an increased risk of developing gallstone disease, but epidemiological studies are lacking. We evaluated the risk of gallstone disease following colectomy and IPAA.

METHODS

Individuals who had a colectomy were identified from a national cohort of patients with ulcerative colitis (UC), and controls without colectomy were sampled from within the same cohort, matching on gender, calendar year, and year of birth. We used Cox regression to examine the effect of colectomy on the hazard rates of gallstone disease and cholecystectomy, adjusting for alcoholism, stroke, chronic obstructive pulmonary disease, cancer, cardiac disease, diabetes mellitus, hypothyroidism, hyperlipidemia, cirrhosis, obesity, renal failure, and transient ischemic attacks. The effect of an IPAA was determined for patients who had colectomy by including the procedure as a time-dependent variable.

RESULTS

We identified 4548 patients and matched these to 44 372 controls without colectomy. During a median follow-up of 11.9 years, 1963 patients were hospitalized for gallstone disease. Patients who had a colectomy were at an increased risk (adjusted hazard ratio (HR)=1.63 (1.39-1.91)), and sensitivity analyses of the risk of undergoing cholecystectomy revealed a similar association (adjusted HR=1.55 (1.22-1.98)). An IPAA did not affect the risk of developing gallstones among patients who had a colectomy (adjusted HR=1.03 (0.77-1.37)).

CONCLUSION

The risk of gallstone disease increases following colectomy for UC.

Probing the Association of Pancreatitis in Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) has been increasingly diagnosed in children and adults. Similarly, acute and chronic pancreatitis are increasingly prevalent conditions with potentially devastating consequences. There is a growing body of literature linking these 2 conditions. The purpose of this review is to provide a comprehensive outline of the association between IBD and pancreatitis and to explore their putative pathophysiology. Based on the collective reports, 2 outstanding reasons for pancreatitis in patients with IBD are medications and IBD complications.

Systematic review: bile acids and intestinal inflammation-luminal aggressors or regulators of mucosal defence?

BACKGROUND

Inflammatory bowel diseases (IBD), comprising Crohn's disease and ulcerative colitis (UC), are chronic conditions attributed to an aberrant immune response to luminal triggers. Recently, published work suggests a pathogenic role for bile acids in this context.

AIM

To perform a systematic review of studies investigating the role of bile acids in intestinal inflammation and present potentially relevant clinical implications.

METHODS

Pubmed search for English language articles published up to May 2015. Terms used were: 'bile', 'bile acid', 'barrier', 'small bowel injury', 'Crohn's' and 'colitis'.

RESULTS

Experimental studies support a variable role for bile acids in intestinal barrier homoeostasis. This may be attributed to different physicochemical properties, variable effects on epithelia and immune cells via bile acids-specific receptors, or through a cross-talk with the gut microbiome. A reduction in the bile acids pool, with lower concentrations of secondary forms, has been recognised for some time in Crohn's disease and associated to ileal dysfunction and bile acids malabsorption. Recent work suggests that these changes, including an increase in sulphated forms, are related to inflammatory activity in both Crohn's disease and UC. The detrimental effects of 'western diet' elements such as emulsifiers and fat, which have been implicated in the development of the current IBD and obesity epidemics, may also be bile acid-mediated.

CONCLUSIONS

Although there are only a few observational clinical studies to support an interaction, in vivo human and animal studies support an association between bile acids metabolism, the gut microbiome and intestinal inflammation. This may well prove to have significant diagnostic and therapeutic implications.

Mucosa-associated Faecalibacterium prausnitzii phylotype richness is reduced in patients with inflammatory bowel disease

Faecalibacterium prausnitzii depletion in intestinal diseases has been extensively reported, but little is known about intraspecies variability. This work aims to determine if subjects with gastrointestinal disease host mucosa-associated F. prausnitzii populations different from those hosted by healthy individuals. A new species-specific PCR-denaturing gradient gel electrophoresis (PCR-DGGE) method targeting the 16S rRNA gene was developed to fingerprint F. prausnitzii populations in biopsy specimens from 31 healthy control (H) subjects and 36 Crohn's disease (CD), 23 ulcerative colitis (UC), 6 irritable bowel syndrome (IBS), and 22 colorectal cancer (CRC) patients. The richness of F. prausnitzii subtypes was lower in inflammatory bowel disease (IBD) patients than in H subjects. The most prevalent operational taxonomic units (OTUs) consisted of four phylotypes (OTUs with a 99% 16S rRNA gene sequence similarity [OTU99]), which were shared by all groups of patients. Their distribution and the presence of some disease-specific F. prausnitzii phylotypes allowed us to differentiate the populations in IBD and CRC patients from that in H subjects. At the level of a minimum similarity of 97% (OTU97), two phylogroups accounted for 98% of the sequences. Phylogroup I was found in 87% of H subjects but in under 50% of IBD patients (P = 0.003). In contrast, phylogroup II was detected in >75% of IBD patients and in only 52% of H subjects (P = 0.005). This study reveals that even though the main members of the F. prausnitzii population are present in both H subjects and individuals with gut diseases, richness is reduced in the latter and an altered phylotype distribution exists between diseases. This approach may serve as a basis for addressing the suitability of F. prausnitzii phylotypes to be quantified as a putative biomarker of disease and depicting the importance of the loss of these subtypes in disease pathogenesis.

Biliary Mucosal Barrier and Microbiome

Background

The biliary system is in continuous contact with the complex microbiota of the intestine. Microbial products have recently been proposed as potential triggers for biliary diseases.

Methods

The aim of this review is to provide a summary of the current knowledge regarding the role of the biliary and intestinal microbiome in biliary inflammatory diseases.

Results

Previously, it was suggested that the healthy biliary system is a sterile organ, while acute cholangitis and cholecystitis may occur from ascending infections. Although non-inflammatory biliary colonization by certain bacteria such as Salmonella spp. has been already recognized since several decades, human and animal studies indicated only very recently that the gallbladder harbors a complex microbiota also under non-pathologic conditions. Novel findings suggested that – similar to the situation in the intestine – the biliary mucosa features a chemical, mechanical, and immunological barrier, ensuring immunological tolerance against commensals. However, microbial triggers might influence acute and chronic inflammatory disease of the biliary system and the whole liver.

Conclusion

Although yet undefined, dysbiosis of the biliary or intestinal microbiota rather than a single microorganism may influence disease progression.

Systematic review: The epidemiology of the hepatobiliary manifestations in patients with inflammatory bowel disease

BACKGROUND

Extraintestinal manifestations are frequent in inflammatory bowel diseases (IBD). Most studies published so far focused on viral hepatitis and liver toxicity of IBD-related drugs.

AIM

To conduct a systematic review of hepatobiliary manifestations associated with IBD. We excluded viral hepatitis and liver toxicity of IBD-related drugs.

METHODS

Studies were identified through the electronic database of MEDLINE, EMBASE and the annual meetings of Digestive Disease Week, the American College of Gastroenterology, the United European Gastroenterology Week and the European Crohn's and Colitis Organization.

RESULTS

One hundred and forty six articles were included in this systematic review. Cholelithiasis is more frequent in Crohn's disease (CD) than in general population. Prevalence of cholelithiasis in CD ranged from 11% to 34%, whereas it ranges from 5.5% to 15% in non-IBD patients. PSC is more frequent in UC than in CD. Prevalence of PSC ranges from 0.76% to 5.4% in UC and from 1.2% to 3.4% in CD. There is a male predominance when PSC is associated with UC, with a male/female ratio ranging from 65/35 to 70/30. No conclusion can be made on a possible increased risk of gall-bladder carcinoma. Mean prevalence of fatty liver is 23% (range, 1.5-55%). Hepatic amyloidosis occurs in less than 1% of IBD. Liver abscess is encountered mainly in CD. Portal vein thrombosis occurs in 39% to 45% of IBD patients undergoing proctocolectomy.

CONCLUSIONS

Hepatobiliary manifestations associated with inflammatory bowel diseases are frequent and probably underdiagnosed.

Cholecystolithiasis is associated with Clonorchis sinensis infection

BACKGROUND

The objective of this study was to analyze gallbladder stones for direct evidence of a relationship between Clonorchis sinensis infection and gallbladder stones formation.

METHODOLOGY

We investigated one hundred eighty-three gallbladder stones for the presence of Clonorchis sinensis eggs using microscopy, and analyzed their composition using Fourier transform infrared spectroscopy. We confirmed the presence of Clonorchis sinensis eggs in the gallbladder stones using real-time fluorescent PCR and scanning electron microscopy.

PRINCIPAL FINDINGS

Clonorchis sinensis eggs were detected in 122 of 183 gallbladder stones based on morphologic characteristics and results from real-time fluorescent PCR. The proportion of pigment stones, cholesterol stones and mixed gallstones in the egg-positive stones was 79.5% (97/122), 3.3% (4/122) and 17.2% (21/122), respectively, while 29.5% (18/61), 31.1% (19/61) and 39.3% (24/61) in the egg-negative stones. The proportion of pigment stone in the Clonorchis sinensis egg-positive stones was higher than in egg-negative stones (P<0.0001). In the 30 egg-positive stones examined by scanning electron microscopy, dozens or even hundreds of Clonorchis sinensis eggs were visible (×400) showing a distinct morphology. Many eggs were wrapped with surrounding particles, and in some, muskmelon wrinkles was seen on the surface of the eggs. Also visible were pieces of texture shed from some of the eggs. Some eggs were depressed or without operculum while most eggs were adhered to or wrapped with amorphous particles or mucoid matter (×3000).

CONCLUSION

Clonorchis sinensis eggs were detected in the gallbladder stones which suggests an association between Clonorchis sinensis infection and gallbladder stones formation, especially pigment stones.

Bile salts induce long polar fimbriae expression favouring Crohn's disease-associated adherent-invasive Escherichia coli interaction with Peyer's patches

Ileal lesions of patients with Crohn's disease are colonized by adherent-invasive Escherichia coli (AIEC). The earliest lesions of recurrent Crohn's disease are erosions of Peyer's patches (PP). We recently reported the presence of a functional lpf operon in AIEC, encoding long polar fimbriae (LPF), that allows AIEC bacteria to interact with PP and to translocate across M cells. The aim of this study was to analyse the effect of gastrointestinal conditions on LPF expression in AIEC strains. The LF82 bacterial growth in an acid pH medium or at high osmolarity medium had no effect on lpf transcription level, in contrast to bacterial growth in the presence of bile salts, which promoted activation of lpf transcription. When cultured in the presence of bile salt, LF82 wild-type bacteria, but not the isogenic mutant deleted for lpfA, exhibited a higher level of interaction with PP and a higher level of translocation through M cell monolayers. The FhlA transcriptional factor was found to be a key bacterial regulator at the origin of LPF expression in the presence of bile salts.

Cultured representatives of two major phylogroups of human colonic Faecalibacterium prausnitzii can utilize pectin, uronic acids, and host-derived substrates for growth

Faecalibacterium prausnitzii is one of the most abundant commensal bacteria in the healthy human large intestine, but information on genetic diversity and substrate utilization is limited. Here, we examine the phylogeny, phenotypic characteristics, and influence of gut environmental factors on growth of F. prausnitzii strains isolated from healthy subjects. Phylogenetic analysis based on the 16S rRNA sequences indicated that the cultured strains were representative of F. prausnitzii sequences detected by direct analysis of fecal DNA and separated the available isolates into two phylogroups. Most F. prausnitzii strains tested grew well under anaerobic conditions on apple pectin. Furthermore, F. prausnitzii strains competed successfully in coculture with two other abundant pectin-utilizing species, Bacteroides thetaiotaomicron and Eubacterium eligens, with apple pectin as substrate, suggesting that this species makes a contribution to pectin fermentation in the colon. Many F. prausnitzii isolates were able to utilize uronic acids for growth, an ability previously thought to be confined to Bacteroides spp. among human colonic anaerobes. Most strains grew on N-acetylglucosamine, demonstrating an ability to utilize host-derived substrates. All strains tested were bile sensitive, showing at least 80% growth inhibition in the presence of 0.5 μg/ml bile salts, while inhibition at mildly acidic pH was strain dependent. These attributes help to explain the abundance of F. prausnitzii in the colonic community but also suggest factors in the gut environment that may limit its distribution.

Crohn's disease as an immunodeficiency

The pathogenesis of Crohn's disease (CD) has widely been regarded as the consequence of a dysregulated T-cell-mediated response to intestinal microbes, and the majority of the worldwide research effort has focused on characterizing and treating the chronic inflammatory phase of the disease. However, recent molecular biological and clinical investigations indicate that CD is actually a primary immunodeficiency. At first counter-intuitive, the apparent paradox of a pathogenic innate immune defect can be linked mechanistically to the granulomatous chronic inflammation characteristic of the disease. Genome-wide association studies have corroborated the involvement of innate immune dysfunction in the pathogenesis of CD, but less than 20% of the heritable risk is accounted for. By contrast, in vitro and in vivo stimulation of the immune system has highlighted novel areas of interest that may lead to the development of targeted therapeutic and diagnostic tools.

Pancreatitis in inflammatory bowel diseases

Crohn's disease and ulcerative colitis, together popularly known as inflammatory bowel disease (IBD), are characterized by a number of extraintestinal manifestations. Although infrequent, acute pancreatitis, and less often chronic pancreatitis, may occur as a result of the disease itself or secondary to the medications used in the treatment. The increased incidence of acute pancreatitis in Crohn's disease can be explained based on the high predisposition to cholesterol as well as pigment stones as a result of ileal disease, anatomic abnormalities of the duodenum, immunologic disturbances associated with IBD, and, above all, to the side effects of many medications used in the treatment. Sulfasalazine, 5-aminosalicylic acid, azathioprine, and 6-mercaptopurine are well known to cause acute pancreatitis as a result of a possible idiosyncratic mechanism. Crohn's disease and ulcerative colitis share many clinical manifestations and treatment modalities. Nonspecific elevations of serum pancreatic enzymes in IBD make it difficult to avoid over diagnosis of acute pancreatitis, particularly in patients with Crohn's disease who suffer from abdominal pain often. The IBD-pancreas association is further reflected in many reports of exocrine as well as endocrine pancreatic insufficiency.

(1)H and (31)P NMR studies indicate reduced bile constituents in patients with biliary obstruction and infection

Patients with extrahepatic biliary obstruction present with impairment of the normal bile flow, with jaundice and cholangitis as common complications. (1)H and (31)P NMR quantitative analysis of bile specimens from patients with extrahepatic biliary obstruction (n = 80) (with/without jaundice and cholangitis separately and together) was carried out for the chief biliary constituents to determine the relationship between biliary constituents and jaundice (serum bilirubin concentration >or=1.0 mg/dL) and cholangitis (total leucocyte count >11,000 cells/mm(3) and/or fever >38.5 degrees C with/without bile culture positivity). Compared with controls (patients without jaundice and cholangitis), median indices of the chief biliary constituents (total bile acids, cholesterol, phosphatidylcholine and inorganic phosphate) were significantly suppressed in patients with cholangitis and/or jaundice. Quantities of total bile acids, cholesterol and phosphatidylcholine correlated negatively with the quantity of bilirubin and with cholangitis, i.e. total leucocyte count. Suppression of biliary constituents correlated significantly with the severity of jaundice and cholangitis. The decrease in biliary constituents in the presence of jaundice and cholangitis is possibly the result of downregulation of the function of transporters located at the canalicular side of hepatocytes, leading to their suppressed indices in bile. This information may have implications in the examination of bile for clinical studies.

Roles of infection, inflammation, and the immune system in cholesterol gallstone formation

Cholesterol gallstone formation is a complex process mediated by genetic and environmental factors. Until recently, the role of the immune system in the pathogenesis of cholesterol gallstones was not considered a valid topic of research interest. This review collates and interprets an extensive body of basic literature, some of which is not customarily considered to be related to cholelithogenesis, describing the multiple facets of the immune system that appear to be involved in cholesterol cholelithogenesis. A thorough understanding of the immune interactions with biliary lipids and cholecystocytes should modify current views of the pathogenesis of cholesterol gallstones, promote further research on the pathways involved, and lead to novel diagnostic tools, treatments, and preventive measures.

Restorative proctocolectomy for ulcerative colitis: impact on lipid metabolism and adipose tissue and serum fatty acids

The aim of this prospective study was to evaluate the changes of the metabolism of circulating and storage lipids in patients with ulcerative colitis after restorative proctocolectomy. Fifteen consecutive patients and 15 sex- and age-matched healthy controls were enrolled. Disease activity, diet, inflammatory parameters, plasma lipoprotein concentrations, and fatty acids (FA) of serum phospholipids and of the subcutaneous adipose tissue were assessed at colectomy and at ileostomy closure. In ulcerative colitis patients, total cholesterol and docosahexaenoic acid were lower than in healthy subjects (p < 0.01 and p < 0.05). The median interval between colectomy and ileostomy closure was 6 (range 2-9) months. During that interval, the inflammatory parameters improved, high-density lipoproteins (HDL) cholesterol increased (p < 0.01), and low-density (LDL) cholesterol decreased (p = 0.01). At ileostomy closure, serum arachidonic acid levels were increased (p = 0.04), whereas serum oleic acid level was decreased (p = 0.02). In this interval, no significant alteration, either in serum n-3 FA precursors or in the FA of subcutaneous adipose tissue, was observed. The increase of serum arachidonic acid after colectomy might suggest a lower utilization for inflammatory process. The reduction of LDL cholesterol is an index of malabsorption probably due to the accelerated transit and to the exclusion of the terminal ileum caused by the covering ileostomy.

Gallstone disease

Gallstone disease is one of the most prevalent gastrointestinal diseases with a substantial burden to health care systems that is supposed to increase in ageing populations at risk. Aetiology and pathogenesis of cholesterol gallstones still are not well defined, and strategies for prevention and efficient nonsurgical therapies are missing. This review summarizes current concepts on the pathogenesis of cholesterol gallstones with focus on the uptake and secretion of biliary lipids and special emphasis on recent studies into the genetic background.

Total parenteral nutrition-related gastroenterological complications

Total parenteral nutrition is a life saving therapy for patients with chronic gastrointestinal failure, being an effective method for supplying energy and nutrients when oral or enteral feeding is impossible or contraindicated. Clinical epidemiological data indicate that total parenteral nutrition may be associated with a variety of problems. Herein we reviewed data on the gastroenterological tract regarding: (i) total parenteral nutrition-related hepatobiliary complications; and (ii) total parenteral nutrition-related intestinal complications. In the first group, complications may vary from mildly elevated liver enzyme values to steatosis, steatohepatitis, cholestasis, fibrosis and cirrhosis. In particular, total parenteral nutrition is considered to be an absolute risk factor for the development of biliary sludge and gallstones and is often associated with hepatic steatosis and intrahepatic cholestasis. In general, the incidence of total parenteral nutrition-related hepatobiliary complications has been reported to be very high, ranging from 20 to 75% in adults. All these hepatobiliary complications are more likely to occur after long-term total parenteral nutrition, but they seem to be less frequent, and/or less severe in patients who are also receiving oral feeding. In addition, end-stage liver disease has been described in approximately 15-20% of patients receiving prolonged total parenteral nutrition. Total parenteral nutrition-related intestinal complications have not yet been adequately defined and described. Epidemiological studies intended to define the incidence of these complications, are still ongoing. Recent papers confirm that in both animals and humans, total parenteral nutrition-related intestinal complications are induced by the lack of enteral stimulation and are characterised by changes in the structure and function of the gut. Preventive suggestions and therapies for both these gastroenterological complications are reviewed and reported in the present review.

Cholesterol gallstone disease

With a prevalence of 10-15% in adults in Europe and the USA, gallstones are the most common digestive disease needing admission to hospital in the West. The interplay between interprandial and postprandial physiological responses to endogenous and dietary lipids underscores the importance of coordinated hepatobiliary and gastrointestinal functions to prevent crystallisation and precipitation of excess biliary cholesterol. Indeed, identifying the metabolic and transcriptional pathways that drive the regulation of biliary lipid secretion has been a major achievement in the field. We highlight scientific advances in protein and gene regulation of cholesterol absorption, synthesis, and catabolism, and biliary lipid secretion with respect to the pathogenesis of cholesterol gallstone disease. We discuss the physical-chemical mechanisms of gallstone formation in bile and the active role of the gallbladder and the intestine. We also discuss gaps in our knowledge of the pathogenesis of gallstone formation and the potential for gene targeting in therapy.

Extraintestinal manifestations of inflammatory bowel diseases

Inflammatory bowel diseases are associated with extraintestinal manifestations involving almost every organ system in the body. They occur in approximately 20% to 40% of patients with inflammatory bowel diseases. Immune-related and genetic mechanisms play an important role in the pathogenesis of these complications. Peripheral arthritis, erythema nodosum, and episcleritis respond to the treatment of the underlying intestinal inflammation, whereas axial arthropathy, pyoderma gangrenosum, and uveitis do not. Immunomodulator therapy, particularly with biologic agents has been shown to be effective in treating some of the extraintestinal manifestations. Early recognition and treatment are crucial in preventing major morbidity.

Gallbladder bile composition in patients with Crohn’s disease

AIM: To further elucidate the pathogenesis and mechanisms of the high risk of gallstone formation in Crohn’s disease.

METHODS: Gallbladder bile was obtained from patients with Crohn’s disease who were admitted for elective surgery (17 with ileal/ileocolonic disease and 7 with Crohn’s colitis). Fourteen gallstone patients served as controls. Duodenal bile was obtained from ten healthy subjects before and after the treatment with ursodeoxycholic acid. Bile was analyzed for biliary lipids, bile acids, bilirubin, crystals, and crystal detection time (CDT). Cholesterol saturation index was calculated.

RESULTS: The biliary concentration of bilirubin was about 50% higher in patients with Crohn’s disease than in patients with cholesterol gallstones. Ten of the patients with Crohn’s disease involving ileum and three of those with Crohn’s colitis had cholesterol saturated bile. Four patients with ileal disease and one of those with colonic disease displayed cholesterol crystals in their bile. About 1/3 of the patients with Crohn’s disease had a short CDT. Treatment of healthy subjects with ursodeoxycholic acid did not increase the concentration of bilirubin in duodenal bile. Several patients with Crohn’s disease, with or without ileal resection/disease had gallbladder bile supersaturated with cholesterol and short CDT and contained cholesterol crystals. The biliary concentration of bilirubin was also increased in patients with Crohn’s colitis probably not due to bile acid malabsorption.

CONCLUSION: Several factors may be of importance for the high risk of developing gallstones of both cholesterol and pigment types in patients with Crohn’s disease.

Gallstone disease: Symptoms and diagnosis of gallbladder stones

The clinical aspects and the diagnostic features of gallstone disease are described. The natural history of silent gallstones is overviewed, and the risk of developing symptoms and complications is also discussed. The importance of colicky pain as a specific gallstone symptom is highlighted, and the role of both laboratory tests and diagnostic investigations for differential diagnosis is discussed. Finally, we describe the diagnostic features of gallbladder stone disease, including indications, sensitivity, specificity, and limitations of different test investigations under special circumstances.

Prevalence of cholelithiasis in patients with chronic inflammatory bowel disease

AIM: To investigate the effect of chronic inflammatory bowel disease (CIBD) specific risk factors for cholecystolithiasis, as duration and involvement pattern of the disease and prior surgery in patients with Crohn's disease (CD) and ulcerative colitis (UC).

METHODS: A total of 222 patients with CD (135 females, 87 males; average age, 35.8 ± 11.8 years; range 17-81 years) and 88 patients with UC (39 females, 49 males; average age, 37.2 ± 13.6 years; range 16-81 years) underwent clinical and ultrasound examinations. Besides age, sex and degree of obesity, patients? CIBD specific parameters, including duration and extent of disease and prior operations were documented and evaluated statistically using logistic regression.

RESULTS: The overall prevalence of gallbladder stone disease in patients with CD was 13% (n = 30). Only age could be shown to be an independent risk factor (P = 0.014). Compared to a collective representative for the general population in the same geographic region, the prevalence of cholecystolithiasis was higher in all corresponding age groups. Patients with UC showed an overall prevalence of gallbladder stone disease of only 4.6%.

CONCLUSION: Only age but not disease-specific factors such as duration and extent of disease, and prior surgery are independent risk factors for the development of cholecystolithiasis in patients with CIBD.

Hepatobiliary, renal and bone complications of intestinal failure

Abnormal liver function tests in patients with intestinal failure (IF) may be due to the underlying disease, IF or the treatments given (including parenteral nutrition (PN)). PN-related liver disease in children usually relates to intrahepatic cholestasis and in adults to steatosis. Steatosis may be consequent upon an excess of carbohydrate, lipid or protein, or upon a deficiency of a specific molecule. Pigment-type gallstones are common in adults and children with IF; these develop from biliary sludge that forms during periods of gallbladder stasis. Ileal disease/resection, parenteral nutrition, surgery, rapid weight loss and drugs all increase the risk of developing gallstones. Gallstone formation may be prevented by reducing gallbladder stasis (oral/enteral feeding or prokinetic agents), altering bile composition, or by means of a prophylactic cholecystectomy. Calcium oxalate renal stones are common in patients with a short bowel and retained functioning colon and are consequent upon increased absorption of dietary oxalate; they are prevented by a low-oxalate diet. An osteopathy may occur with long-term parenteral nutrition.