Gut transit is associated with gastrointestinal symptoms and gut hormone profile in patients with cirrhosis

Development and validation of a novel nomogram model to assess the risk of gastric contents in outpatients undergoing elective sedative gastrointestinal endoscopy procedures

BACKGROUND

Gastric contents may contribute to patients' aspiration during anesthesia. Ultrasound can accurately assess the risk of gastric contents in patients undergoing sedative gastrointestinal endoscopy (GIE) procedures, but its efficiency is limited. Therefore, developing an accurate and efficient model to predict gastric contents in outpatients undergoing elective sedative GIE procedures is greatly desirable.

METHODS

This study retrospectively analyzed 1501 patients undergoing sedative GIE procedures. Gastric contents were observed under direct gastroscopic vision and suctioned through the endoscope. High-risk gastric contents were defined as having solid content or liquid volume > 25 ml and pH < 2.5; otherwise, they were considered low-risk gastric contents. Univariate analysis and multivariate analysis were used to select the independent risk factors to predict high-risk gastric contents. Based on the selected independent risk factors, we assigned values to each independent risk factor and established a novel nomogram. The performance of the nomogram was verified in the testing cohort by the metrics of discrimination, calibration, and clinical usefulness. In addition, an online accessible web calculator was constructed.

RESULTS

We found BMI, cerebral infarction, cirrhosis, male, age, diabetes, and gastroesophageal reflux disease were risk factors for gastric contents. The AUROCs were 0.911 and 0.864 in the development and testing cohort, respectively. Moreover, the nomogram showed good calibration ability. Decision curve analysis and Clinical impact curve demonstrated that the predictive nomogram was clinically useful. The website of the nomogram was https://medication.shinyapps.io/dynnomapp/.

CONCLUSIONS

This study demonstrates that clinical variables can be combined with algorithmic techniques to predict gastric contents in outpatients. Nomogram was constructed from routine variables, and the web calculator had excellent clinical applicability to assess the risk of gastric contents accurately and efficiently in outpatients, assist anesthesiologists in assessment and identify the most appropriate patients for ultrasound.

Aetiology, diagnosis and management of small intestinal bacterial overgrowth

Small intestinal bacterial overgrowth is a small bowel disorder characterised by excessive amounts of bacteria populating the small intestine leading to symptoms of abdominal pain, bloating and change in bowel habit. This creates some degree of diagnostic uncertainty due to the overlap of these symptoms with numerous other gastrointestinal conditions. Quantitative culture of jejunal aspirates is the gold standard diagnostic test but has largely been replaced by glucose and lactulose breath tests due to their relative ease and accessibility. The approach to treatment centres around reducing bacterial numbers through antibiotic therapy and managing any predisposing factors. Further research is required in order to define the optimum antibiotic choice and duration of therapy as well as the potential diagnostic utility of home breath testing and capsule-based technology.

Reversal of Feed Intolerance by Prokinetics Improves Survival in Critically Ill Cirrhosis Patients

BACKGROUND AND AIMS

Feed intolerance (FI) is common in cirrhosis patients in intensive care units (ICU). Prokinetics are the first line treatment for FI but their efficacy and safety in critically ill patient with cirrhosis is unknown. We evaluated the role of prokinetics in reversal of FI and clinical outcomes.

METHODS

Consecutive patients admitted in ICU developing new-onset FI, were randomized to receive either intravenous metoclopramide (Gr.A, n = 28), erythromycin (Gr.B, n = 27) or placebo (Gr.C, n = 28). FI was defined with the presence of 3 of 5 variables- absence of bowel sounds, gastric residual volume ≥ 500 ml, vomiting, diarrhoea and bowel distension. Primary end-point was complete resolution of FI (≥ 3 variables resolved) within 24-h and secondary end-points included resolution within 72-h and survival at 7-days.

RESULTS

Of the 1030 ICU patients, 201 (19.5%) developed FI and 83 patients were randomized. Baseline parameters between the groups were comparable. Complete resolution at 24-h was higher in Gr.A (7.14%) and B (22.2%) than C (0%, p = 0.017). Overall, 58 (69.9%) patients achieved resolution within 72 h, more with metoclopramide (n = 24, 85.7%) and erythromycin (n = 25, 92.6%) than with placebo (n = 9, 32.1%, p < 0.001). The 7-day survival was better in patients who achieved resolution within 72-h (65.5 vs. 36%, p = 0.011) than non-responders. High lactate (OR-3.32, CI-1.45-7.70, p = 0.005), shock at baseline (OR-6.34, CI-1.67-24.1, p = 0.007) and resolution of FI within 72 h (OR-0.11, CI, 0.03-0.51, p = 0.04) predicted 7-day mortality.

CONCLUSIONS

FI is common in critically-ill cirrhosis patients and non-resolution carries high mortality. Early recognition and treatment with prokinetics is recommended to improve short-term survival.

Leaky Gut and Gut-Liver Axis in Liver Cirrhosis: Clinical Studies Update

Portal blood flows into the liver containing the gut microbiome and its products such as endotoxin and bacterial DNA. The cirrhotic liver acts and detoxifies as the initial site of microbial products. In so-called "leaky gut," the increased intestinal permeability for bacteria and their products constitutes an important pathogenetic factor for major complications in patients with liver cirrhosis. Prolonged gastric and small intestinal transit may induce intestinal bacterial overgrowth, a condition in which colonic bacteria translocate into the small gut. Cirrhotic patients further show gut dysbiosis characterized by an overgrowth of potentially pathogenic bacteria and a decrease in autochthonous nonpathogenic bacteria. Pathological bacterial translocation (BT) is a contributing factor in the development of various severe complications. Bile acids (BAs) undergo extensive enterohepatic circulation and play important roles in the gut-liver axis. BT-induced inflammation prevents synthesis of BAs in the liver through inhibition of BA-synthesizing enzyme CYP7A1. A lower abundance of 7α-dehydroxylating gut bacteria leads to decreased conversion of primary to secondary BAs. Decreases in total and secondary BAs may play an important role in the gut dysbiosis characterized by a proinflammatory and toxic gut microbiome inducing BT and endotoxemia, as addressed in my previous reviews. Selective intestinal decontamination by the use of various antimicrobial drugs for management of complications has a long history. Lactobacillus GG decreasing endotoxemia is reported to improve the microbiome with beneficial changes in amino acid, vitamin and secondary BA metabolism. Current approaches for hepatic encephalopathy are the use of nonabsorbable antibiotics and disaccharides. Probiotics may become an additional therapeutic option for advanced liver cirrhosis.

Chronic Liver Disease Increases Mortality Following Pancreatoduodenectomy

According to the International Study Group of Pancreatic Surgery (ISGPS), data about the impact of pre-existing liver pathologies on delayed gastric emptying (DGE) after pancreatoduodenectomy (PD) according to the definitions of the International Study Group of Pancreatic Surgery (ISGPS) are lacking. We therefore investigated the impact of DGE after PD according to ISGPS in patients with liver cirrhosis (LC) and advanced liver fibrosis (LF). Patients were analyzed with respect to pre-existing liver pathologies (LC and advanced LF, n = 15, 6% vs. no liver pathologies, n = 240, 94%) in relation to demographic factors, comorbidities, intraoperative characteristics, mortality and postoperative complications, with special emphasis on DGE. DGE was equally distributed (DGE grade A, p = 1.000; B, p = 0.396; C, p = 0.607). Particularly, the first day of solid food intake (p = 0.901), the duration of intraoperative administered nasogastric tube (NGT) (p = 0.812), the rate of re-insertion of NGT (p = 0.072), and the need for parenteral nutrition (p = 0.643) did not differ. However, patients with LC and advanced LF showed a higher ASA (American Society of Anesthesiologists) score (p = 0.016), intraoperatively received more erythrocyte transfusions (p = 0.029), stayed longer in the intensive care unit (p = 0.010) and showed more intraabdominal abscess formation (p = 0.006). Moreover, we did observe a higher mortality rate amongst patients with pre-existing liver diseases (p = 0.021), and reoperation was a risk factor for higher mortality (p ≤ 0.001) in the multivariate analysis. In our study, we could not detect a difference with respect to DGE classified by ISGPS; however, we did observe a higher mortality rate amongst these patients and thus, they should be critically evaluated for PD.

Malnutrition in cirrhosis: More food for thought

Malnutrition is highly prevalent in liver cirrhosis and its presence carries important prognostic implications. The clinical conditions and pathophysiological mechanisms that cause malnutrition in cirrhosis are multiple and interrelated. Anorexia and liver decompensation symptoms lead to poor dietary intake; metabolic changes characterised by elevated energy expenditure, reduced glycogen storage, an accelerated starvation response and protein catabolism result in muscle and fat wasting; and, malabsorption renders the cirrhotic patient unable to fully absorb or utilise food that has been consumed. Malnutrition is therefore a considerable challenge to manage effectively, particularly as liver disease progresses. A high energy, high protein diet is recognised as standard of care, yet patients struggle to follow this recommendation and there is limited evidence to guide malnutrition interventions in cirrhosis and liver transplantation. In this review, we seek to detail the factors which contribute to poor nutritional status in liver disease, and highlight complexities far greater than "poor appetite" or "reduced oral intake" leading to malnutrition. We also discuss management strategies to optimise nutritional status in this patient group, which target the inter-related mechanisms unique to advanced liver disease. Finally, future research requirements are suggested, to develop effective treatments for one of the most common and debilitating complications afflicting cirrhotic patients.

Current Status and Prospects of Spontaneous Peritonitis in Patients with Cirrhosis

Spontaneous bacterial peritonitis (SBP) is a common cirrhotic ascites complication which exacerbates the patient's condition. SBP is caused by gram-negative bacilli and, to a lesser extent, gram-positive cocci. Hospital-acquired infections show higher levels of drug-resistant bacteria. Geographical location influences pathogenic bacteria distribution; therefore, different hospitals in the same country record different bacteria strains. Intestinal changes and a weak immune system in patients with liver cirrhosis lead to bacterial translocation thus causing SBP. Early diagnosis and timely treatment are important in SBP management. When the treatment effect is not effective, other rare pathogens should be explored.

Xiaozhang Tie Improves Intestinal Motility in Rats With Cirrhotic Ascites by Regulating the Stem Cell Factor/c-kit Pathway in Interstitial Cells of Cajal

We previously discovered that Xiaozhang Tie (XZT) was helpful for cirrhotic ascites, with obvious abdominal distention relief, suggesting that it may improve gastrointestinal (GI) motility. However, the underlying mechanisms of GI motility in cirrhotic ascites are unclear. Here, we aimed to discover explored the effect of XZT on GI motility in animal cirrhotic ascites and probed the action mechanism affecting GI motility by regulating the stem cell factor (SCF)/c-kit pathway in interstitial cells of Cajal (ICCs) and GI hormones. First, rat models of cirrhotic ascites were developed and then divided randomly into the following three subgroups: model control, XZT group, and mosapride group. The efficacy of XZT on treating cirrhotic ascites was evaluated on the basis of ascites weight and volume, 24 h urine volume, and feces water content. GI motility of the cirrhotic model, intestine propulsion, and gastric residue were detected using the migration distance of ink in vivo, and the frequency of contraction and tension of isolated gastric and jejunal muscle strips were measured after incubation with XZT extracts. Serum GI hormone content, including motilin (MTL), substance P (SP), somatostatin (SS), and vasoactive intestinal polypeptide were assayed. Subsequently, ICCs were isolated from jejunum, and primarily cultured ICCs were incubated with and without XZT and SCF. The cell vitality of the ICCs was measured. A whole-cell patch recording technique was used to record the current of K⁺ and Na⁺ channels in the ICC membrane. Expressions of c-kit/p-c-kit, p-Akt, p-STAT3, and p-Erk1/2 were detected in vivo and in vitro. The results revealed that XZT significantly reduced ascites weight and increased urine volume and fecal water content in model rats. XZT promoted intestinal motility and increased MTL level but reduced SP and SS levels. It enhanced the current of Na⁺ and K⁺ in ICCs and improved c-kit expression and signaling mediator phosphorylation in SCF/c-kit, which was inhibited by imatinib in vitro and downregulated in model rats in vivo. Our study concluded that XZT reduced the amount of ascites and improved intestinal motility in cirrhotic rats, which may be associated with its effect on ascites and was involved in the mechanisms regulating the SCF/c-kit signaling pathway in ICCs and improving gastrointestinal hormone secretion.

Acid suppression therapy and its association with spontaneous bacterial peritonitis incidence: A systemic review and meta-analysis

AIM

It is well known that the use of proton pump inhibitor (PPI) is widespread in patients with liver cirrhosis. PPI counteracts H₂ receptor inhibitor (H₂ RA) with its strong acid suppression effect. However, there is always a concern that PPI use may increase spontaneous bacteria peritonitis (SBP) development in cirrhotic patients. We aimed to investigate the association between acid suppression therapy (i.e. PPI or H₂ RA) and SBP through meta-analysis.

METHODS

We searched PubMed, Medline, Web of Science, Cochrane library, and Embase for relevant studies published up to April 2019. Pooled OR and 95% CI were calculated by a random-effects model. Funnel plots and Egger's tests were performed for the evaluation of publication bias. Non-parametric "trim-and-fill" tests were conducted for sensitivity analysis.

RESULTS

A total of 20 original articles including 9566 cirrhotic patients were analyzed. The overall meta-analysis highlighted that PPI use was associated with the risk of SBP (pooled OR 1.77, 95% CI 1.49-2.11). The conclusion was irrespective of study methods, whereas the result was inconsistent only in South America. However, the conclusion might not be stable enough and should be extrapolated with caution. Unlike PPI, we found H₂ RA was not associated with SBP (pooled OR 1.06, 95% CI 0.75-1.48).

CONCLUSIONS

In conclusion, PPI use, but not H₂ RA, will increase the incidence of SBP in cirrhotic patients. In addition, H₂ RA might be beneficial for patients who require long-term acid suppression therapy.

Xiaozhang Tie Improves Intestinal Motility in Rats With Cirrhotic Ascites by Regulating the Stem Cell Factor/c-kit Pathway in Interstitial Cells of Cajal

We previously discovered that Xiaozhang Tie (XZT) was helpful for cirrhotic ascites, with obvious abdominal distention relief, suggesting that it may improve gastrointestinal (GI) motility. However, the underlying mechanisms of GI motility in cirrhotic ascites are unclear. Here, we aimed to discover explored the effect of XZT on GI motility in animal cirrhotic ascites and probed the action mechanism affecting GI motility by regulating the stem cell factor (SCF)/c-kit pathway in interstitial cells of Cajal (ICCs) and GI hormones. First, rat models of cirrhotic ascites were developed and then divided randomly into the following three subgroups: model control, XZT group, and mosapride group. The efficacy of XZT on treating cirrhotic ascites was evaluated on the basis of ascites weight and volume, 24 h urine volume, and feces water content. GI motility of the cirrhotic model, intestine propulsion, and gastric residue were detected using the migration distance of ink in vivo, and the frequency of contraction and tension of isolated gastric and jejunal muscle strips were measured after incubation with XZT extracts. Serum GI hormone content, including motilin (MTL), substance P (SP), somatostatin (SS), and vasoactive intestinal polypeptide were assayed. Subsequently, ICCs were isolated from jejunum, and primarily cultured ICCs were incubated with and without XZT and SCF. The cell vitality of the ICCs was measured. A whole-cell patch recording technique was used to record the current of K⁺ and Na⁺ channels in the ICC membrane. Expressions of c-kit/p-c-kit, p-Akt, p-STAT3, and p-Erk1/2 were detected in vivo and in vitro. The results revealed that XZT significantly reduced ascites weight and increased urine volume and fecal water content in model rats. XZT promoted intestinal motility and increased MTL level but reduced SP and SS levels. It enhanced the current of Na⁺ and K⁺ in ICCs and improved c-kit expression and signaling mediator phosphorylation in SCF/c-kit, which was inhibited by imatinib in vitro and downregulated in model rats in vivo. Our study concluded that XZT reduced the amount of ascites and improved intestinal motility in cirrhotic rats, which may be associated with its effect on ascites and was involved in the mechanisms regulating the SCF/c-kit signaling pathway in ICCs and improving gastrointestinal hormone secretion.

Gastric food retention at endoscopy is associated with severity of liver cirrhosis

BACKGROUND

Gastrointestinal symptoms are prevalent in patients with cirrhosis. Cirrhotic patients have a known predilection to delayed gastric emptying compared to those without cirrhosis. However, the contributing factors have not been fully elucidated. Retained gastric food on esophagogastroduodenoscopy (EGD) has been used as a surrogate marker for delayed gastric emptying with reasonably high specificity. Therefore, we hypothesize that the frequency of retained gastric food contents at EGD will be higher in a cirrhotic population compared to a control population without liver disease. Additionally, we hypothesize that increased frequency of gastric food contents will be associated with increased severity of cirrhosis.

AIM

To determine the relative frequency of delayed gastric emptying among cirrhotics as compared to non-cirrhotics and to identify associated factors.

METHODS

We performed a retrospective case-control study of cirrhotic subjects who underwent EGD at an academic medical center between 2000 and 2015. Three hundred sixty-four patients with confirmed cirrhosis, who underwent a total of 1044 EGDs for the indication of esophageal variceal screening or surveillance, were identified. During the same period, 519 control patients without liver disease, who underwent a total of 881 EGDs for the indication of anemia, were identified. The presence of retained food on EGD was used as a surrogate for delayed gastric emptying. The relative frequency of delayed gastric emptying among cirrhotics was compared to non-cirrhotics. Characteristics of patients with and without retained food on EGD were compared using univariable and multivariable logistic regression analysis to identify associated factors.

RESULTS

Overall, 40 (4.5%) patients had evidence of retained food on EGD. Cirrhotics were more likely to have retained food on EGD than non-cirrhotics (9.1% vs 1.4%, P < 0.001). Characteristics associated with retained food on univariable analysis included age less than 60 years (12.6% vs 5.2%, P = 0.015), opioid use (P = 0.004), Child-Pugh class C (24.1% Child-Pugh class C vs 6.4% Child-Pugh class A, P = 0.007), and lower platelet count (P = 0.027). On multivariate logistic regression analysis, in addition to the presence of cirrhosis (adjusted OR = 5.83; 95%CI: 2.32-14.7, P < 0.001), diabetes mellitus (types 1 and 2 combined) (OR = 2.34; 95%CI: 1.08-5.06, P = 0.031), opioid use (OR = 3.08; 95%CI: 1.29-7.34, P = 0.011), and Child-Pugh class C (OR = 4.29; 95%CI: 1.43-12.9, P = 0.01) were also associated with a higher likelihood of food retention on EGD.

CONCLUSION

Cirrhotics have a higher frequency of retained food at EGD than non-cirrhotics. Decompensated cirrhosis, defined by Child-Pugh class C, is associated with a higher likelihood of delayed gastric emptying.

Gastrointestinal Failure in Critically Ill Patients With Cirrhosis

Gastrointestinal failure (GIF) is frequent in patients managed in the intensive care units and manifests as gut paralysis or ileus. GIF is often associated with sepsis or multiorgan failure. In critically ill patients, the precipitating causes of GIF include inflammation, sepsis, electrolyte abnormalities, and acidosis. It is possible that GIF is associated with an increase in bacterial translocation, especially in those with cirrhosis and portal hypertension, and this may play a significant pathogenic or prognostic role in acute-on-chronic liver failure (ACLF). The critical care literature suggests that GIF is associated with a higher mortality risk. In this review, we summarize the evidence for a potential association between GIF and ACLF and propose treatment options for the management of GIF. Moreover, we suggest GIF to be considered as another organ failure when the severity of ACLF is assessed.

Small Intestinal Bacterial Overgrowth in Patients With Cirrhosis

Small intestinal bacterial overgrowth (SIBO) is defined by increased density and/or abnormal composition of microbiota in the small bowel. SIBO is often encountered in patients with cirrhosis as a result of impaired intestinal motility and delayed transit time, both of which are exacerbated by more severe liver disease. Additional risk factors for SIBO commonly encountered in cirrhotic patients include coexisting diabetes, autonomic neuropathy, and/or alcoholic use. Diagnosis of SIBO is performed by breath testing or jejunal aspiration, the gold standard. In cirrhotic patients, the presence of SIBO can lead to profound clinical consequences. Increased intestinal permeability in these patients predisposes to bacterial translocation into the systemic circulation. As a result, SIBO is implicated as a significant risk factor in the pathogenesis of both spontaneous bacterial peritonitis and hepatic encephalopathy in cirrhotics. Antibiotics, especially rifaximin, are the best studied and most effective treatment options for SIBO. However, prokinetics, probiotics, nonselective beta-blockers, and treatment of underlying liver-related pathophysiology with transjugular intrahepatic portosystemic shunt placement or liver transplantation are also being investigated. This review will discuss the risk factors, diagnosis, manifestations in cirrhosis, and treatment options of SIBO.

A correlation between gastrointestinal dysfunction and cirrhosis severity

This study aims to investigate the relationship between gastrointestinal dysfunction (GD) and cirrhosis severity in cirrhotic patients, to provide evidences for the prevention and treatment of GD in cirrhotic patients.A total of 95 cirrhotic inpatients and outpatients, who were treated in the Department of Gastroenterology of Xinqu Hospital of the First Affiliated Hospital of Henan University of Science and Technology, were enrolled in the present study, and assigned as the experimental group (cirrhosis group). According to Child-Pugh classification, these patients were divided into 3 groups: group A (n = 45), group B (n = 23), and group C (n = 27). Forty healthy adults who received health check-ups during the same period served as the control group. The gastrointestinal (GI) symptoms of cirrhotic patients were scored, and the fasting serum gastrin (GAS), motilin (MTL), and vasoactive intestinal peptide (VIP) levels were measured in all subjects.The potential correlations of GI symptom scores of patients in these cirrhosis groups with GI hormone levels and cirrhosis severity were analyzed. In cirrhotic patients, the GI symptom scores significantly increased. Furthermore, the symptom scores gradually increased along with the aggravation of liver damage. Moreover, serum GAS and VIP levels were significantly higher in the cirrhosis groups than in the control group, whereas MTL levels were significantly lower. These changes were significantly correlated with cirrhosis severity. The linear correlation analysis revealed that the GI symptom score was positively correlated with GAS and VIP levels, and negatively correlated with MTL level. In addition, the linear correlation analysis revealed that GI symptom score and GAS and VIP levels were positively correlated with cirrhosis severity, whereas MTL level was negatively correlated with cirrhosis severity.Cirrhotic patients have more obvious GI symptoms and higher GI hormone levels, which are closely correlated with the progression of liver cirrhosis and the degree of liver function damage.

Small Bowel Transit and Altered Gut Microbiota in Patients With Liver Cirrhosis

Disturbance of the gut microbiota is common in liver cirrhosis (LC) patients, the underlying mechanisms of which are yet to be unfolded. This study aims to explore the relationship between small bowel transit (SBT) and gut microbiota in LC patients. Cross-sectional design was applied with 36 LC patients and 20 healthy controls (HCs). The gut microbiota was characterized by 16S rRNA gene sequencing. The Firmicutes/Bacteroidetes (F/B) ratio and the Microbial Dysbiosis index (MDI) were used to evaluate the severity of microbiota dysbiosis. The scintigraphy method was performed in patients to describe the objective values of SBT. Patients were then subdivided according to the Child–Pugh score (threshold = 5) or SBT value (threshold = 0.6) for microbiota analysis. LC patients were characterized by an altered gut microbiota; F/B ratios and MDI were higher than HC in both Child_5 (14.00 ± 14.69 vs. 2.86 ± 0.99, p < 0.01; 0.49 ± 0.80 vs. -0.47 ± 0.69, p < 0.01) and Child_5+ (15.81 ± 15.11 vs. 2.86±0.99, p < 0.01; 1.11 ± 1.05 vs. -0.47 ± 0.69, p < 0.01) sub-groups in patients. Difference in the gut microbiota between Child_ 5 and Child_5+ patients was inappreciable, but the SBT was relatively slower in Child_5+ patients (43 ± 26% vs. 80 ± 15%, p < 0.05). Compared with the Child–Pugh score indicators, SBT showed stronger associations with bacterial genera. A clear difference in the gut microbiota was observed between SBT_0.6- and SBT_0.6+ patients [Pr(>F) = 0.0068, pMANOVA], with higher F/B ratios and MDI in SBT_0.6- patients (19.71 ± 16.62 vs. 7.33 ± 6.65, p < 0.01; 1.02 ± 0.97 vs. 0.20 ± 0.58, p < 0.01). Similar results were observed between the SBT_0.6- and SBT_0.6+ sub-groups of patients with normal liver function and a Child–Pugh score of 5. SBT was negatively correlated with both the F/B ratio and MDI (r = -0.34, p < 0.05; r = -0.38, p < 0.05). Interestingly, an increased capacity for the inferred pathway “bacterial invasion of epithelial cells” in patients, was highly negatively correlated with SBT (r = -0.57, p < 0.01). The severity of microbiota dysbiosis in LC patients depends on SBT rather than Child–Pugh score. SBT per se might be significantly related to the gut microbiota abnormalities observed in patients with LC.

Small Bowel Motility

PURPOSE OF REVIEW

Small bowel motility disorders constitute a relatively small but important segment of clinical gastroenterology. Presenting features encompass a broad range of symptom manifestations and severity: from chronic functional-type complaints to life-threatening nutritional impairment. Diagnostic assessment of patients with suspected intestinal motility disorders is often hampered by the complexity of measuring intestinal contractile activity in humans. In this review, we describe and critically comment the main current and forthcoming methodologies.

RECENT FINDINGS

Beyond conventional small bowel manometry, radiological methods, and intestinal transit tests that have been available for several decades, now we focus on novel methodologies such as high-resolution manometry, magnetic resonance methodology, and endoluminal capsule image analysis. Gradual introduction of new approaches to diagnostic investigation of patients with suspected intestinal motility disorders should facilitate a less invasive and more accurate characterization of disturbed motor function. Enhanced understanding of the pathophysiological basis of clinical conditions should allow better application of therapeutic approaches that are also highlighted in this review.

Gastrointestinal Motility Disorders and Their Clinical Implications in Cirrhosis

Gastrointestinal motility is impaired in a substantial proportion of patients with cirrhosis. Cirrhosis-related autonomic neuropathy, increased nitric oxide production, and gut hormonal changes have been implicated. Oesophageal dysmotility has been associated with increased frequency of abnormal gastro-oesophageal reflux. Impaired gastric emptying and accommodation may result in early satiety and may have an impact on the nutritional status of these patients. Small intestinal dysmotility might be implicated in small intestinal bacterial overgrowth and increased bacterial translocation. The latter has been implicated in the pathophysiology of hepatic encephalopathy and spontaneous bacterial peritonitis. Enhanced colonic motility is usually associated with the use of lactulose. Pharmacological interventions aiming to alter gastrointestinal motility in cirrhosis could potentially have a beneficial effect reducing the risk of hepatic decompensation and improving prognosis.

Changes of Intestinal Functions in Liver Cirrhosis

Background

Understanding of the gut-liver axis is important for the up-to-date management of liver cirrhosis, and changes of intestinal functions form the core of this interesting research field.

Summary

Most investigators noted small intestinal dysmotility in their patients with liver cirrhosis. Marked changes in the contraction pattern were observed in early manometric studies. The orocecal transit time, particularly small intestinal transit, has generally been reported to be prolonged, which has been demonstrated in multiple investigations to be related to the severity of the liver disease (e.g., Child-Pugh class), the presence of small intestinal bacterial overgrowth (SIBO) and hepatic encephalopathy (HE) as well as a history of spontaneous bacterial peritonitis. Bacteriologically proven SIBO in proximal jejunal aspiration has been reported to be present in up to 59% of cirrhotic patients and is associated with systemic endotoxemia. Clinical and experimental studies suggest that delayed small bowel transit in liver cirrhosis may lead to SIBO, which could contribute to the symptoms of abdominal pain and diarrhea. In addition to autonomic neuropathy, metabolic derangements and diabetic state, SIBO itself may delay intestinal transit in cirrhotic patients. Several studies, both from the West and the East, have shown that the gut microbiota is altered in cirrhotic patients and particularly those with HE. Further, a quantitative change in Bacteroides/Firmicutes ratio, with a prevalence of potentially pathogenic bacteria (e.g., Enterobacteriaceae) and reduction in specific commensals (e.g., Lachnospiraceae), has been described. Structural and functional changes in the intestinal mucosa that contribute to increases in intestinal permeability for bacteria and their products have been observed in patients with liver cirrhosis, which is considered as an important pathogenetic factor for several complications. The mechanism of intestinal barrier dysfunction in cirrhosis is multifactorial, including alcohol, portal hypertension (vascular congestion and dysregulation), endotoxemia, SIBO, local inflammation and, most likely, immunological factors and medications.

Key Messages

This review summarizes major achievements regarding intestinal dysfunction in cirrhosis for future gastroenterology research. The question of whether this intestinal barrier dysfunction is accompanied and/or at least partly caused by structural and functional changes in the epithelial tight junction proteins is as yet unsolved. Development of new strategies to modulate gut-liver interaction is urgently needed.

Changes of Intestinal Functions in Liver Cirrhosis

BACKGROUND

Understanding of the gut-liver axis is important for the up-to-date management of liver cirrhosis, and changes of intestinal functions form the core of this interesting research field.

SUMMARY

Most investigators noted small intestinal dysmotility in their patients with liver cirrhosis. Marked changes in the contraction pattern were observed in early manometric studies. The orocecal transit time, particularly small intestinal transit, has generally been reported to be prolonged, which has been demonstrated in multiple investigations to be related to the severity of the liver disease (e.g., Child-Pugh class), the presence of small intestinal bacterial overgrowth (SIBO) and hepatic encephalopathy (HE) as well as a history of spontaneous bacterial peritonitis. Bacteriologically proven SIBO in proximal jejunal aspiration has been reported to be present in up to 59% of cirrhotic patients and is associated with systemic endotoxemia. Clinical and experimental studies suggest that delayed small bowel transit in liver cirrhosis may lead to SIBO, which could contribute to the symptoms of abdominal pain and diarrhea. In addition to autonomic neuropathy, metabolic derangements and diabetic state, SIBO itself may delay intestinal transit in cirrhotic patients. Several studies, both from the West and the East, have shown that the gut microbiota is altered in cirrhotic patients and particularly those with HE. Further, a quantitative change in Bacteroides/Firmicutes ratio, with a prevalence of potentially pathogenic bacteria (e.g., Enterobacteriaceae) and reduction in specific commensals (e.g., Lachnospiraceae), has been described. Structural and functional changes in the intestinal mucosa that contribute to increases in intestinal permeability for bacteria and their products have been observed in patients with liver cirrhosis, which is considered as an important pathogenetic factor for several complications. The mechanism of intestinal barrier dysfunction in cirrhosis is multifactorial, including alcohol, portal hypertension (vascular congestion and dysregulation), endotoxemia, SIBO, local inflammation and, most likely, immunological factors and medications.

KEY MESSAGES

This review summarizes major achievements regarding intestinal dysfunction in cirrhosis for future gastroenterology research. The question of whether this intestinal barrier dysfunction is accompanied and/or at least partly caused by structural and functional changes in the epithelial tight junction proteins is as yet unsolved. Development of new strategies to modulate gut-liver interaction is urgently needed.

Changes of Intestinal Functions in Liver Cirrhosis

Background

Understanding of the gut-liver axis is important for the up-to-date management of liver cirrhosis, and changes of intestinal functions form the core of this interesting research field.

Summary

Most investigators noted small intestinal dysmotility in their patients with liver cirrhosis. Marked changes in the contraction pattern were observed in early manometric studies. The orocecal transit time, particularly small intestinal transit, has generally been reported to be prolonged, which has been demonstrated in multiple investigations to be related to the severity of the liver disease (e.g., Child-Pugh class), the presence of small intestinal bacterial overgrowth (SIBO) and hepatic encephalopathy (HE) as well as a history of spontaneous bacterial peritonitis. Bacteriologically proven SIBO in proximal jejunal aspiration has been reported to be present in up to 59% of cirrhotic patients and is associated with systemic endotoxemia. Clinical and experimental studies suggest that delayed small bowel transit in liver cirrhosis may lead to SIBO, which could contribute to the symptoms of abdominal pain and diarrhea. In addition to autonomic neuropathy, metabolic derangements and diabetic state, SIBO itself may delay intestinal transit in cirrhotic patients. Several studies, both from the West and the East, have shown that the gut microbiota is altered in cirrhotic patients and particularly those with HE. Further, a quantitative change in Bacteroides/Firmicutes ratio, with a prevalence of potentially pathogenic bacteria (e.g., Enterobacteriaceae) and reduction in specific commensals (e.g., Lachnospiraceae), has been described. Structural and functional changes in the intestinal mucosa that contribute to increases in intestinal permeability for bacteria and their products have been observed in patients with liver cirrhosis, which is considered as an important pathogenetic factor for several complications. The mechanism of intestinal barrier dysfunction in cirrhosis is multifactorial, including alcohol, portal hypertension (vascular congestion and dysregulation), endotoxemia, SIBO, local inflammation and, most likely, immunological factors and medications.

Key Messages

This review summarizes major achievements regarding intestinal dysfunction in cirrhosis for future gastroenterology research. The question of whether this intestinal barrier dysfunction is accompanied and/or at least partly caused by structural and functional changes in the epithelial tight junction proteins is as yet unsolved. Development of new strategies to modulate gut-liver interaction is urgently needed.

Molecular changes in hepatic metabolism and transport in cirrhosis and their functional importance

Liver cirrhosis is the common endpoint of many hepatic diseases and represents a relevant risk for liver failure and hepatocellular carcinoma. The progress of liver fibrosis and cirrhosis is accompanied by deteriorating liver function. This review summarizes the regulatory and functional changes in phase I and phase II metabolic enzymes as well as transport proteins and provides an overview regarding lipid and glucose metabolism in cirrhotic patients. Interestingly, phase I enzymes are generally downregulated transcriptionally, while phase II enzymes are mostly preserved transcriptionally but are reduced in their function. Transport proteins are regulated in a specific way that resembles the molecular changes observed in obstructive cholestasis. Lipid and glucose metabolism are characterized by insulin resistance and catabolism, leading to the disturbance of energy expenditure and wasting. Possible non-invasive tests, especially breath tests, for components of liver metabolism are discussed. The heterogeneity and complexity of changes in hepatic metabolism complicate the assessment of liver function in individual patients. Additionally, studies in humans are rare, and species differences preclude the transferability of data from rodents to humans. In clinical practice, some established global scores or criteria form the basis for the functional evaluation of patients with liver cirrhosis, but difficult treatment decisions such as selection for transplantation or resection require further research regarding the application of existing non-invasive tests and the development of more specific tests.

Nutritional care in hospitalized patients with chronic liver disease

AIM: To evaluate the practice of nutritional assessment and management of hospitalised patients with cirrhosis and the impact of malnutrition on their clinical outcome.

METHODS: This was a retrospective cohort study on patients with liver cirrhosis consecutively admitted to the Department of Gastroenterology and Hepatology at the Royal Adelaide Hospital over 24 mo. Details were gathered related to the patients’ demographics, disease severity, nutritional status and assessment, biochemistry and clinical outcomes. Nutritional status was assessed by a dietician and determined by subjective global assessment. Estimated energy and protein requirements were calculated by Simple Ratio Method. Intake was estimated from dietary history and/or food charts, and represented as a percentage of estimated daily requirements. Median duration of follow up was 14.9 (0-41.4) mo.

RESULTS: Of the 231 cirrhotic patients (167 male, age: 56.3 ± 0.9 years, 9% Child-Pugh A, 42% Child-Pugh B and 49% Child-Pugh C), 131 (57%) had formal nutritional assessment during their admission and 74 (56%) were judged to have malnutrition. In-hospital caloric (15.6 ± 1.2 kcal/kg vs 23.7 ± 2.3 kcal/kg, P = 0.0003) and protein intake (0.65 ± 0.06 g/kg vs 1.01 ± 0.07 g/kg, P = 0.0003) was significantly reduced in patients with malnutrition. Of the malnourished cohort, 12 (16%) received enteral nutrition during hospitalisation and only 6 (8%) received ongoing dietetic review and assessment following discharge from hospital. The overall mortality was 51%, and was higher in patients with malnutrition compared to those without (HR = 5.29, 95%CI: 2.31-12.1; P < 0.001).

CONCLUSION: Malnutrition is common in hospitalised patients with cirrhosis and is associated with higher mortality. Formal nutritional assessment, however, is inadequate. This highlights the need for meticulous nutritional evaluation and management in these patients.

Influence of gastrointestinal factors on glucose metabolism in patients with cirrhosis

BACKGROUND AND AIM

The impaired glucose tolerance in cirrhosis is poorly understood. We evaluated the influence of gastrointestinal-mediated glucose disposal and incretin effect in patients with cirrhosis.

METHODS

Non-diabetic patients with Child-Pugh A or B cirrhosis (n = 10) and matched healthy controls (n = 10) underwent a 50-g oral glucose tolerance test (OGTT) and an isoglycemic intravenous glucose infusion. We presented data as median ± interquartile range and compared groups using non-parametric analysis of variance.

RESULTS

Patients with cirrhosis were glucose intolerant compared with healthy controls (4-h OGTTAUC : 609 ± 458 vs 180 ± 155 min × mmol/L; P = 0.005), insulin resistant (homeostatic model assessment for insulin resistance: 3.7 ± 4.9 vs 2.6 ± 1.4; P = 0.014) and had fasting hyperglucagonemia (8 ± 3 vs 3 ± 4 pmol/L; P = 0.027). Isoglycemia was achieved using 35 ± 12 g of intravenous glucose in patients with cirrhosis compared with 24 ± 10 g in healthy controls (P = 0.003). The gastrointestinal-mediated glucose disposal was markedly lower in patients with cirrhosis (30 ± 23 vs 52 ± 20%; P = 0.003). Despite higher levels of the incretin hormones glucagon-like peptide-1 and glucose-dependent insulinotropic peptide patients with cirrhosis had reduced incretin effect (35 ± 44 vs 55 ± 30%; P = 0.008).

CONCLUSION

Impaired gastrointestinal-mediated glucose disposal and reduced incretin effect may contribute to the glucose intolerance seen in patients with cirrhosis.

Effect of biliary cirrhosis on neurogenic relaxation of rat gastric fundus and anococcygeus muscle: role of nitric oxide pathway

BACKGROUND

Cirrhosis, associated with a host of hemodynamic abnormalities, could affect the gastrointestinal (GI) tract motility. On the other hand, the nonadrenergic noncholinergic (NANC) neurotransmission has been shown to play a pivotal role in GI tract motility and has been linked with release of nitric oxide (NO) on electrical stimulation. In this study, we investigated the effect of biliary cirrhosis on the neurogenic relaxation of rat gastric fundus and anococcygeus muscle and also the possible role of nitric oxide system in this manner.

METHODS

Isolated gastric fundus and anococcygeus strips of sham-operated and biliary cirrhotic (4 weeks after bile duct ligation) rats were mounted under tension in a standard organ bath. Electrical stimulation was applied to obtain NANC-mediated relaxations in precontracted gastric fundus and anococcygeus muscle. The neurogenic relaxations were examined in the presence of different doses of NO synthase inhibitor, N (w)-Nitro-L-Arginine Methyl Ester (L-NAME). The concentration-dependent relaxant responses to the NO donor sodium nitroprusside were also evaluated.

RESULTS

The neurogenic relaxation of both gastric fundus and anococcygeus muscle was significantly (P < 0.001) increased in cirrhotic animals. L-NAME (0.03-1,000 µM) inhibited relaxations in both groups in a dose-dependent manner (P < 0.001), but cirrhotic groups were more resistant to the inhibitory effects of L-NAME (P < 0.01). Sodium nitroprusside-mediated relaxations were similar in two groups.

CONCLUSIONS

This study for the first time demonstrated that cirrhosis increases the NO-mediated neurogenic relaxation of both rat gastric fundus and anococcygeus muscle, suggesting a crucial role for the neurogenic NO in the pathophysiology of disturbed GI motility in cirrhosis.

Gastrointestinal motility and changes of serum motilin and gastrin in conscious heat stroke rats

AIM: To establish a conscious heat stroke (HS) rat model to investigate heat stroke-induced gastrointestinal motility and changes of serum motilin (MTL) and gastrin (GAS).

METHODS: A conscious HS rat model was established using artificial experimental environment simulation cabin (AEESC). The changes of gastric mucosal gland morphology was observed by light microscopy. The blue Sephadex-2000 marker was used to determine the rates of gastric emptying (GAS) and small intestinal transit (SIT). Serum and gastrointestinal contents of MTL and GAS were detected by ELISA, and expression of GAS and MT in the gastrointestinal mucosa gland was observed by the immunohistochemical technique.

RESULTS: Compared with normal controls, the rates of GE and SIP were significantly lower in HS rats, while serum GAS and MTL levels were significantly higher (P < 0.05). Serum GAS and MTL peaked at 16 h and then rapidly decreased, while gastric GAS peaked at 8 h. The longer the thermal stimulation time, the lower the concentration of MTL in the duodenum (P < 0.05). With the increase of thermal stimulation time, the rats showed gastric mucosal gland structure disturbance, glandular epithelial disarrangement, cloudy swelling, and glandular cavity narrowing or missing. Finally, glandular epithelial degeneration and gland structure destruction were observed, and the size, color and distribution of granules in the cytoplasm of gland cells were significantly changed.

CONCLUSION: The changes of serum MTL and GAS may be indicators to judge abnormal gastrointestinal motility in conscious heat stroke rats.

Gastrointestinal symptoms in patients with cirrhosis: a longitudinal study before and after liver transplantation

OBJECTIVE

Gastrointestinal (GI) symptoms are common in cirrhosis and have an impact on quality of life. Their pathophysiology and their relation to energy intake have not been fully elucidated and the effect of liver transplantation on GI symptoms has not been studied. We aimed to prospectively evaluate GI symptoms and their determinants before and after transplantation and their potential relation with energy intake in cirrhosis.

METHODS

A total of 108 cirrhotic liver transplant candidates completed the Gastrointestinal Symptom Rating Scale (GSRS) and the hospital anxiety and depression scale. Fasting serum glucose and insulin were measured in all patients. Serum thyrotropin, free T3/T4, cortisol, free testosterone, estradiol, dehydroepiandrosterone sulfate, interleukin-6 and tumor necrosis factor-α were measured in a subgroup of 80 patients. Transplant recipients were followed for 1 year. A separate cohort of 40 cirrhotic patients underwent a high-caloric satiation drinking test (SDT).

RESULTS

GI symptoms were more severe in cirrhotics compared to controls from the general population. In regression analysis, the total GSRS score was independently related to lactulose, anxiety and low free testosterone (p < 0.05 for all). Four out of six GSRS domain scores improved significantly 1 year post-transplant (p < 0.05) but the total GSRS score remained higher compared to controls. GI symptoms predicted ingestion of fewer calories at SDT compared to other patients and controls (p < 0.05).

CONCLUSIONS

Psychological distress, lactulose treatment and low testosterone are predictors of GI symptoms which are common among cirrhotic transplant candidates. They are also associated with decreased energy intake as measured by a SDT. GI symptoms remain of concern post-transplant.

Small intestinal transit in patients with liver cirrhosis and portal hypertension: a descriptive study

Background

Gastrointestinal dysmotility may be involved in the development of bacterial translocation and infection in patients with liver cirrhosis. The aim of the present study was to describe gastric, small intestinal and colorectal motility and transit in patients with liver cirrhosis and portal hypertension using a magnet-based Motility Tracking System (MTS-1) and standard radiopaque markers.

Methods

We included 15 patients with liver cirrhosis (8 Child-Pugh A, 6 Child-Pugh B, and 1 Child-Pugh C) and portal hypertension (11 males, median age 54 years (range 38–73), median hepatic venous pressure gradient 18 mmHg (range 12–37)), and 18 healthy controls (8 males, median age 58 years (range 34–64)). The gastric emptying time and small intestinal motility were evaluated by MTS-1, and the total gastrointestinal transit time was assessed by radiopaque markers and abdominal radiographs.

Results

The velocity through the proximal small intestine was significantly higher in cirrhotic patients (median 1.27 metres (m)/hour, range 0.82–2.68) than in the healthy controls (median 1.00 m/hour, range 0.46–1.88) (p = 0.03). Likewise, the magnet travelled significantly longer in both fast (p = 0.04) and slow movements (p = 0.05) in the patient group. There was no significant difference in either gastric emptying time—23 minutes (range 5–131) in patients and 29 minutes (range 10.5–182) in healthy controls (p = 0.43)—or total gastrointestinal transit time—1.6 days (range 0.5–2.9) in patients and 2.0 days (range 1.0–3.9) in healthy controls (p = 0.33). No correlation was observed between the hepatic venous pressure gradient and the velocity of the magnet through the small intestine.

Conclusion

Patients with liver cirrhosis and portal hypertension demonstrated faster-than-normal transit through the proximal small intestine. This may be due to an overactive bowel, as suggested by previous studies.

Abnormal plasma peptide YY(3-36) levels in patients with liver cirrhosis

OBJECTIVE

Peptide YY(3-36) (PYY(3-36)) is a gut hormone with anorectic action that also affects energy expenditure. Anorexia and malnutrition are often observed in patients with decompensated liver cirrhosis (LC), whereas patients with LC after insertion of transjugular portosystemic stent shunts (TIPS) show normal eating behavior. The underlying mechanism of anorexia in decompensated LC and its resolution in patients with TIPS is still unclear. We thus investigated fasting and postprandial PYY(3-36) serum levels in patients with decompensated LC, patients with compensated LC with in situ TIPS, and healthy controls.

METHODS

We analyzed fasting PYY(3-36) levels in six patients with decompensated LC (four men and two women, 55 ± 11 y of age), nine patients with TIPS (seven men and two women, 48 ± 11 y of age), and 10 controls (eight men and two women, 43 ± 9 y of age) postprandially after a standardized meal of 300 kcal and during 1-h continuous parenteral nutrition. Energy expenditure was determined by indirect calorimetry.

RESULTS

At baseline PYY(3-36) was comparable in controls and patients with TIPS (91 ± 10 and 89 ± 25 ng/L) but was increased in patients with decompensated LC (165 ± 44 ng/L, P < 0.01). Although the cumulative postprandial PYY(3-36) increase was similar in controls (mean 2089 ng/240 min per liter) and patients with decompensated LC (mean 1735 ng/240 min per liter), no postprandial PYY(3-36) increase was observed in patients with TIPS (mean -579 ng/240 min per liter). Parenteral nutrition did not significantly affect PYY(3-36) levels in any group. Fasting PYY(3-36) values were negatively related to resting energy expenditure (r = -0.443, P = 0.030). PYY(3-36) was not associated to liver parameters (e.g., bilirubin, alanine aminotransferase).

CONCLUSION

Our results demonstrate an abnormal neuroendocrine regulation of PYY(3-36) in patients with decompensated LC and those with TIPS.

Changes in body composition after transjugular intrahepatic portosystemic stent in cirrhosis: a critical review of literature

Change in body composition with reduced muscle mass with or without loss of fat mass occurs in 60-90% of patients with cirrhosis. This has an adverse impact on the outcome of these patients and is an understudied area. Transjugular intrahepatic portosystemic stent (TIPS) is now a standard therapy for portal hypertension but its beneficial impact on nutritional indices is not well recognized. We included all publications on TIPS that had any nutritional index as an outcome measure or end point. Given the heterogeneity of the patient population, differences in study design and outcome measures, a meta-analysis was not feasible. Data were summarized and interpreted. A total of eight studies have been published on the changes in body composition after TIPS in cirrhosis in a total of 152 patients followed for 3-12 months. Improvement in fat-free mass and fluid-free or ascites-free body weight was reported in all studies. Plasma leptin, IGF1, insulin sensitivity, rate of glucose disposal and growth hormone did not change after TIPS. One study measured muscle strength that improved. Direct measurement of skeletal muscle mass was not performed in any study. TIPS resulted in an improvement in body composition. Given the clinical significance of skeletal muscle and fat mass in cirrhosis, nutritional indices should be considered to be an important outcome measure in patients with TIPS. The mechanism of these is unclear, but its clinical implication is that this may contribute to the improved survival after TIPS.

Role of small intestinal bacterial overgrowth and delayed gastrointestinal transit time in cirrhotic patients with minimal hepatic encephalopathy

BACKGROUND & AIMS

Minimal hepatic encephalopathy (MHE) is the mildest form in the spectrum of hepatic encephalopathy. This cross-sectional study was carried out to elucidate the role of bacterial overgrowth of the small intestine and delayed intestinal transit among patients with MHE.

METHODS

Two-hundred-thirty patients with cirrhosis were screened; 102 patients (44.4%) who met the eligibility criteria were included in the study. MHE was diagnosed when the psychometric hepatic encephalopathy score was ≤-5. All patients underwent a glucose breath test for small intestinal bacterial overgrowth (SIBO) and lactulose breath test for oro-cecal transit time (OCTT).

RESULTS

Fifty-seven (55.9%) patients with cirrhosis had MHE. Among these patients with MHE, 22 (38.6%) had SIBO, while 4 (8.9%) without MHE had SIBO (p = 0.001). The prevalence of SIBO was higher in patients with CTP classes B and C (69.2%) compared to those in CTP class A (30.8%); p = 0.054. OCTT was significantly prolonged in patients who had SIBO than in those who did not have SIBO (p<0.0001). Univariate analysis demonstrated that increased age, female gender, low educational status, low albumin, presence of SIBO, and prolonged OCTT were associated with the presence of MHE. Multivariate analysis demonstrated SIBO as the only factor associated with MHE.

CONCLUSIONS

Our study conclusively demonstrates high prevalence of SIBO in patients with cirrhosis with MHE. This study gives the rationale of treatment directed against SIBO and gut dysmotility, which may include non-absorbable antibiotics such as rifaximin, probiotics, and prokinetics.

Altered fasting and postprandial plasma ghrelin levels in patients with liver failure are normalized after liver transplantation

CONTEXT

Anorexia is a problem of paramount importance in patients with advanced liver failure. Ghrelin has important actions on feeding and weight homeostasis. Experimental data exist, which suggest that ghrelin could protect hepatic tissue. Both fasting and post-oral glucose tolerance test (OGTT) ghrelin concentrations are controversial in liver cirrhosis and are unknown after liver transplantation.

OBJECTIVE

Our aim was to study fasting ghrelin concentrations and their response to an OGTT in liver failure patients before and after liver transplantation.

DESIGN AND METHODS

We included 21 patients with severe liver failure studied before (pretransplantation, PreT) and 6 months after liver transplantation (posttransplantation, PostT), and 10 age- and body mass index-matched healthy or overweight subjects as the control group (Cont). After an overnight fast, 75 g of oral glucose were administered; glucose, insulin, and ghrelin were obtained at baseline and at times 30, 60, 90, and 120 min.

RESULTS

Fasting ghrelin (median and range, pg/ml) levels were lower in PreT: 539 (309-1262) than in Cont: 643 (523-2163), P=0.045. Fasting ghrelin levels increased after liver transplantation, 539 (309-1262) vs 910 (426-3305), for PreT and PostT respectively, P=0.001. The area under the curve (AUC) of ghrelin (pg/ml min) was lower in PreT: 63,900 (37,260-148,410) than in Cont: 76,560 (56,160-206,385), P=0.027. The AUC of ghrelin increased in PostT, 63,900 (37,260-148,410) vs 107,595 (59,535-357,465), for PreT and PostT respectively, P=0.001. Fasting levels and the AUC of ghrelin were similar in PosT and Cont.

CONCLUSIONS

Decreased fasting and post-OGTT ghrelin levels in liver failure patients were normalized after liver transplantation.

Ghrelin gene products and the regulation of food intake and gut motility

A breakthrough using "reverse pharmacology" identified and characterized acyl ghrelin from the stomach as the endogenous cognate ligand for the growth hormone (GH) secretagogue receptor (GHS-R) 1a. The unique post-translational modification of O-n-octanoylation at serine 3 is the first in peptide discovery history and is essential for GH-releasing ability. Des-acyl ghrelin, lacking O-n-octanoylation at serine 3, is also produced in the stomach and remains the major molecular form secreted into the circulation. The third ghrelin gene product, obestatin, a novel 23-amino acid peptide identified from rat stomach, was found by comparative genomic analysis. Three ghrelin gene products actively participate in modulating appetite, adipogenesis, gut motility, glucose metabolism, cell proliferation, immune, sleep, memory, anxiety, cognition, and stress. Knockdown or knockout of acyl ghrelin and/or GHS-R1a, and overexpression of des-acyl ghrelin show benefits in the therapy of obesity and metabolic syndrome. By contrast, agonism of acyl ghrelin and/or GHS-R1a could combat human anorexia-cachexia, including anorexia nervosa, chronic heart failure, chronic obstructive pulmonary disease, liver cirrhosis, chronic kidney disease, burn, and postsurgery recovery, as well as restore gut dysmotility, such as diabetic or neurogenic gastroparesis, and postoperative ileus. The ghrelin acyl-modifying enzyme, ghrelin O-Acyltransferase (GOAT), which attaches octanoate to serine-3 of ghrelin, has been identified and characterized also from the stomach. To date, ghrelin is the only protein to be octanylated, and inhibition of GOAT may have effects only on the stomach and is unlikely to affect the synthesis of other proteins. GOAT may provide a critical molecular target in developing novel therapeutics for obesity and type 2 diabetes.