Effect of oral glutamine supplementation on gut permeability and endotoxemia in patients with severe acute pancreatitis: a randomized controlled trial

Feeding Intolerance-A Key Factor in the Management of Acute Pancreatitis: A Review

Acute pancreatitis (AP) is one of the most common diseases of the gastrointestinal tract, which in 20% of cases can turn into a severe form, with mortality reaching up to 30%. One of the cornerstones of AP treatment is early nutritional treatment. Feeding intolerance (FI) occurs in up to 25% of patients with AP and is associated with a more severe disease course and poorer clinical outcome. Feeding intolerance can have a multifaceted clinical presentation. The early identification of FI risk factors and appropriately conducted nutritional treatment are critical to the course of the disease. In this review, we summarize the current knowledge of feeding intolerance in AP, its pathomechanisms and risk factors, and its impact on disease progression. We also present suggestions for the management of feeding intolerance.

A systematic review and meta-analysis of clinical trials on the effects of glutamine supplementation on gut permeability in adults

The gastrointestinal tract's epithelial barrier plays a crucial role in maintaining health. This study aims to investigate the impact of glutamine supplementation on intestinal permeability, considering its importance for immune function and nutrient absorption. The study adhered to the PRISMA protocol for systematic reviews and meta-analyses. A systematic search was performed in four databases (PubMed, Scopus, Web of Science, and Google Scholar) until April 2023 to identify clinical trials on glutamine supplementation and gastrointestinal permeability. Eligibility criteria included randomized placebo-controlled trials measuring gut permeability post-glutamine supplementation. Studies were included regardless of language or publication date. Data extraction involved study characteristics, intervention details, and outcomes. Quality assessment was performed using the Cochrane tool, and statistical analysis utilized mean differences and standard deviations with a random effects model. Subgroup analysis was conducted to explore heterogeneity. The systematic review and meta-analysis included 10 studies from 1998 to 2014 with 352 participants. A total of 216 patients were enrolled in the intervention group, and 212 in the control group. The mean participant age was 46.52 years. The participants had different types of diseases in terms of their health status. Overall, glutamine supplementation did not significantly affect intestinal permeability (WMD: -0.00, 95% CI -0.04, 0.03). Subgroup analysis showed a significant reduction in intestinal permeability with doses over 30g/day (WMD: -0.01, 95% CI -0.10, -0.08). The glutamine supplements were administered orally in all included studies. The meta-analysis demonstrated a significant reduction in intestinal permeability with glutamine supplementation exceeding 30 mg/day for durations of less than 2 weeks. Further investigations with varying dosages and patient populations are warranted to enhance understanding and recommendations regarding glutamine supplementation's effects on gut permeability.

Fire in the belly: A scoping review of the immunopathological mechanisms of acute pancreatitis

Introduction

Acute pancreatitis (AP) is characterised by an inflammatory response that in its most severe form can cause a systemic dysregulated immune response and progression to acute multi-organ dysfunction. The pathobiology of the disease is unclear and as a result no targeted, disease-modifying therapies exist. We performed a scoping review of data pertaining to the human immunology of AP to summarise the current field and to identify future research opportunities.

Methods

A scoping review of all clinical studies of AP immunology was performed across multiple databases. Studies were included if they were human studies of AP with an immunological outcome or intervention.

Results

205 studies met the inclusion criteria for the review. Severe AP is characterised by significant immune dysregulation compared to the milder form of the disease. Broadly, this immune dysfunction was categorised into: innate immune responses (including profound release of damage-associated molecular patterns and heightened activity of pattern recognition receptors), cytokine profile dysregulation (particularly IL-1, 6, 10 and TNF-α), lymphocyte abnormalities, paradoxical immunosuppression (including HLA-DR suppression and increased co-inhibitory molecule expression), and failure of the intestinal barrier function. Studies including interventions were also included. Several limitations in the existing literature have been identified; consolidation and consistency across studies is required if progress is to be made in our understanding of this disease.

Conclusions

AP, particularly the more severe spectrum of the disease, is characterised by a multifaceted immune response that drives tissue injury and contributes to the associated morbidity and mortality. Significant work is required to develop our understanding of the immunopathology of this disease if disease-modifying therapies are to be established.

Efficacy of Glutamine in Treating Severe Acute Pancreatitis: A Systematic Review and Meta-Analysis

Objectives

The prognosis of severe acute pancreatitis (SAP) patients is closely related to early nutritional support. It is well-established that changes in glutamine (Gln), an important amino acid and nutritional supplement, can reflect disease severity. However, no consensus has been reached on the role of Gln nutrition therapy for SAP patients. We conducted this systematic review and meta-analysis to summarize and evaluate the advantages of Gln supplementation in SAP.

Methods

PubMed, Web of Science, the Embase, Cochrane Library, and Chinese databases (CNKI, SinoMed, Wanfang, and VIP) were systematically searched for eligible studies that included glutamine supplementation in SAP patients from inception to October 31 2021, excluding non-SAP studies. Primary outcome measures included mortality, APACHE II score, complications, and length of hospital stay. The meta-analysis was registered with PROSPERO (CRD42021288371) and was conducted using Review Manager and Stata softwares.

Results

This meta-analysis included 30 randomized controlled trials (RCTs) with a total of 1,201 patients. Six primary outcomes and six secondary outcomes were analyzed. For the primary outcomes, Gln supplementation was associated with lower mortality (OR = 0.38, 95% CI: 0.21-0.69, P = 0.001), total hospital stay (MD = -3.41, 95% CI: -4.93 to -1.88, P < 0.0001) and complications (OR = 0.45, 95% CI: 0.31-0.66, P < 0.0001) compared with conventional nutrition. Further subgroup analysis found that parenteral glutamine was more effective in reducing mortality. In terms of secondary outcomes, Gln supplementation helped restore liver, kidney and immune function, with significantly increased serum albumin (SMD = 1.02, 95% CI: 0.74-1.31, P < 0.00001) and IgG levels (MD = 1.24, 95% CI: 0.82-1.67, P < 0.00001), and decreased serum creatinine (Scr) (MD = -12.60, 95% CI: -21.97 to -3.24, P = 0.008), and inflammatory indicators such as C-reaction protein (CRP) (SMD = -1.67, 95% CI: -2.43 to -0.90, P < 0.0001).

Conclusion

Although Gln supplementation is not routinely recommended, it is beneficial for SAP patients. Indeed, glutamine nutrition has little effect on some indicator outcomes but contributes to improving the prognosis of this patient population.Systematic Review Registration: PROSPERO (york.ac.uk). Unique Identifier: CRD42021288371.

Nutritional Support in Patients with Severe Acute Pancreatitis-Current Standards

Severe acute pancreatitis (SAP) leads to numerous inflammatory and nutritional disturbances. All SAP patients are at a high nutritional risk. It has been proven that proper nutrition significantly reduces mortality rate and the incidence of the infectious complications in SAP patients. According to the literature, early (started within 24-48 h) enteral nutrition (EN) is optimal in most patients. EN protects gut barrier function because it decreases gastrointestinal dysmotility secondary to pancreatic inflammation. Currently, the role of parenteral nutrition (PN) in SAP patients is limited to patients in whom EN is not possible or contraindicated. Early versus delayed EN, nasogastric versus nasojejunal tube for EN, EN versus PN in SAP patients and the role of immunonutrition (IN) in SAP patients are discussed in this review.

Combined Exercise Training and l-Glutamine Supplementation Enhances Both Humoral and Cellular Immune Responses after Influenza Virus Vaccination in Elderly Subjects

Background: Since aging affects the immune responses against vaccination, the present study evaluated the effects of L-glutamine (Gln) supplementation in the humoral and cellular immune responses in elderly subjects, practitioners or not, of physical exercise training. Methods: Eighty-four elderly people (aged 72.6 ± 6.1), non-practitioners (NP, n = 31), and practitioners of combined-exercise training (CET, n = 53) were submitted to Influenza virus vaccination and supplemented with Gln (0.3 g/kg of weight + 10 g of maltodextrin, groups: NP-Gln (n = 14), and CET-Gln (n = 26)), or placebo (10 g of maltodextrin, groups: NP-PL (n = 17), and CET-PL (n = 27)). Blood samples were collected pre (baseline) and 30 days post-vaccination and supplementation. Results: Comparing with the baseline values, whereas the NP-Gln and CET-PL groups showed higher specific-IgM levels, the CET-Gln group showed higher specific-IgM and IgA levels post-vaccination. The titer rate of hemagglutination inhibition was higher in the CET-Gln, NP-PL, and NP-Gln groups post-vaccination than baseline values. The absolute number of naive and effector CD4+ T cells was higher especially in the NP-Gln and CET-Gln groups, whilst activated CD4+ T cells were higher in CET subgroups post-vaccination. Conclusion: Our results showed that both l-glutamine supplementation and combined-exercise training can improve the immune responses to the Influenza virus vaccine in elderly subjects.

Association of endotoxaemia & gut permeability with complications of acute pancreatitis: Secondary analysis of data

Background & objectives:

In acute pancreatitis (AP) gut barrier dysfunction is considered as an important predisposing factor leading to increased intestinal permeability (IP). In this study a pooled analysis of data published in our previous four studies on various aspects of gut permeability and endotoxaemia in patients with AP was attempted to find an association between increased IP and severity of disease and associated complications.

Methods:

This study was a pooled analysis of data of four previously published prospective studies on AP. Gut permeability, assessed by lactulose/mannitol excretion in urine and endotoxin core antibodies type IgG and IgM (EndoCab IgG and IgM) were measured on days zero and seven (D0 and D7) of admission. All patients received standard treatment of AP. We studied whether IgG and IgM anti-endotoxin titres and lactulose-mannitol ratio (LMR) at admission and D7 were associated with organ failure, infection and mortality.

Results:

The titres of anti-endotoxin IgG and IgM were lower in all patients of AP (n=204), both in mild AP (n=24) and severe AP (n=180) in the first week, compared to controls (n=15). There was no significant difference in serum IgG and IgM anti-endotoxin levels and LMR at baseline and at D7 among patients with organ failure, infection and mortality.

Interpretation & conclusions:

Our findings showed that serum IgG and IgM anti-endotoxin titres and LMR at admission and at day 7 were not associated with organ failure, infection, and death of patients with AP.

Challenge to the Intestinal Mucosa During Sepsis

Sepsis is a complex of life-threating organ dysfunction in critically ill patients, with a primary infectious cause or through secondary infection of damaged tissues. The systemic consequences of sepsis have been intensively examined and evidences of local alterations and repercussions in the intestinal mucosal compartment is gradually defining gut-associated changes during sepsis. In the present review, we focus on sepsis-induced dysfunction of the intestinal barrier, consisting of an increased permeability of the epithelial lining, which may facilitate bacterial translocation. We discuss disturbances in intestinal vascular tonus and perfusion and coagulopathies with respect to their proposed underlying molecular mechanisms. The consequences of enzymatic responses by pancreatic proteases, intestinal alkaline phosphatases, and several matrix metalloproteases are also described. We conclude our insight with a discussion on novel therapeutic interventions derived from crucial aspects of the gut mucosal dynamics during sepsis.

A meta-analysis of early oral refeeding and quickly increased diet for patients with mild acute pancreatitis

BACKGROUND/AIM

The objective of the study is to clarify whether early oral refeeding (EORF) and quickly increasing diet (QID) are of benefit to patients with mild acute pancreatitis compared with a traditional oral refeeding strategy.

MATERIALS AND METHODS

Studies were searched in PubMed, Cochrane library, ScienceDirect, SpringerLink, China Biology Medicine disc and Embase. A meta-analysis was then performed, using relapse of abdominal pain, nausea/vomiting, and length of hospital stay (LOHS) as the evaluation indices.

RESULTS

Eight trials met the inclusion criteria. For the oral refeeding time group, EORF could significantly decrease the LOHS (mean deviation [MD] -1.97; 95% confidence interval (CI) -3.32 to -0.62;P = 0.004), and there was no significant difference for relapse of abdominal pain (relative risk [RR] 1.17; 95% CI 0.69-2.00;P = 0.56) or nausea/vomiting (RR 1.30; 95% CI 0.19-8.82;P = 0.79) when compared with conventional oral refeeding. For the oral refeeding material group, there was no significant difference for relapse of abdominal pain (RR 0.86; 95% CI 0.53-1.40;P = 0.54), nausea/vomiting (risk difference -0.01; 95% CI -0.19-0.18;P = 0.94), or LOHS (MD -0.88; 95% CI -2.24-0.48;P = 0.20) between the QID and stepwise increasing diet groups.

CONCLUSION

Pure EORF or QID caused no damage to patients with mild acute pancreatitis, and EORF could significantly decrease the LOHS.

Exogenous glutamine impairs neutrophils migration into infections sites elicited by lipopolysaccharide by a multistep mechanism

Glutamine (GLN) is the most abundant free amino acid in the body, and is considered as a conditionally essential amino acid under stress conditions, acting as an important modulator of the immune response. We here investigated the role of exogenous GLN treatment on leukocyte migration after the onset of endotoxemia and the intracellular mechanisms of GLN actions on neutrophils. Two in vivo models of endotoxemia caused by lipopolysaccharide of Escherichia coli (LPS) injection were carried out in male outbred Balb/C mice 2-3 months old, as follow: (1) LPS (50 μg/kg) was intravenously injected 1 h prior to intravenous injection of GLN (0.75 mg/kg) and samples were collected 2 h later to investigate the role of GLN on the acute lung inflammation; (2) LPS (1 mg/kg) was intraperitoneally injected 1 h prior to intravenous injection of GLN (0.75 mg/kg) and samples were collected 18 h later to measure the effects of GLN on local and later phases of inflammation in the peritoneum. Results showed that GLN administration reduced the number of neutrophils in the inflamed lungs, partially recovery of the reduced number of leukocytes in the blood; reduced adhesion molecules on lung endothelium and on circulating neutrophils. Moreover, GLN treatment diminished the number of neutrophils, levels of chemotactic cytokine CXCL2 in the inflamed peritoneum, and neutrophils collected from the peritoneum of GLN-treated mice presented lower levels of Rho, Rac, and JNK. Together, our data show novel mechanisms involved in the actions of GLN on neutrophils migration.

Effect of high dose lactulose on intra-abdominal hypertension and intestinal mucosal barrier function in patients with moderate acute pancreatitis

AIM

To investigate the effect of high dose lactulose on intra-abdominal hypertension and intestinal mucosal barrier function in patients with moderate acute pancreatitis.

METHODS

Ninety patients with moderate acute pancreatitis admitted to Taishun County People's Hospital from February 2015 to February 2017 were included and randomly divided into an observation group and a control group, with 45 cases in each group. On the basis of conventional symptomatic treatment, both groups were treated with somatostatin and esomeprazole, and the observation group was additionally treated with high dose lactulose. Hospitalization time, time to abdominal pain relief, time to intestinal function recovery, intra-abdominal hypertension, intestinal mucosal barrier function, and therapeutic effect were compared between the two groups.

RESULTS

Hospitalization time, time to abdominal pain relief, and time to intestinal function recovery were significantly shorter in the observation group than in the control group (P < 0.05). Intra-abdominal hypertension, endotoxin, D-lactic acid, diamine oxidase, and urinary amylase levels in the observation group after treatment were lower than those in the control group (P < 0.05). The total effective rate in the observation group (95.11%) was higher than that in the control group (80.00%; P < 0.05).

CONCLUSION

The combination of high dose lactulose with somatostatin and esomeprazole can reduce intra-abdominal hypertension and endotoxin, D-lactic acid, diamine oxidase, and urinary amylase levels and enhance intestinal mucosal barrier function in patients with moderate acute pancreatitis.

Recent Advances on Nutrition in Treatment of Acute Pancreatitis

Acute pancreatitis (AP) is a common abdominal acute inflammatory disorder and the leading cause of hospital admission for gastrointestinal disorders in many countries. Clinical manifestations of AP vary from self-limiting local inflammation to devastating systemic pathological conditions causing significant morbidity and mortality. To date, despite extensive efforts in translating promising experimental therapeutic targets in clinical trials, disease-specific effective remedy remains obscure, and supportive care has still been the primary treatment for this disease. Emerging evidence, in light of the current state of pathophysiology of AP, has highlighted that strategic initiation of nutrition with appropriate nutrient supplementation are key to limit local inflammation and to prevent or manage AP-associated complications. The current review focuses on recent advances on nutritional interventions including enteral versus parenteral nutrition strategies, and nutritional supplements such as probiotics, glutamine, omega-3 fatty acids, and vitamins in clinical AP, hoping to advance current knowledge and practice related to nutrition and nutritional supplements in clinical management of AP.

Key Molecular Mechanisms of Chaiqinchengqi Decoction in Alleviating the Pulmonary Albumin Leakage Caused by Endotoxemia in Severe Acute Pancreatitis Rats

To reveal the key molecular mechanisms of Chaiqinchengqi decoction (CQCQD) in alleviating the pulmonary albumin leakage caused by endotoxemia in severe acute pancreatitis (SAP) rats. Rats models of SAP endotoxemia-induced acute lung injury were established, the studies in vivo provided the important evidences that the therapy of CQCQD significantly ameliorated the increases in plasma levels of lipopolysaccharide (LPS), sCd14, and Lbp, the elevation of serum amylase level, the enhancements of systemic and pulmonary albumin leakage, and the depravation of airways indicators, thus improving respiratory dysfunction and also pancreatic and pulmonary histopathological changes. According to the analyses of rats pulmonary tissue microarray and protein-protein interaction network, c-Fos, c-Src, and p85α were predicted as the target proteins for CQCQD in alleviating pulmonary albumin leakage. To confirm these predictions, human umbilical vein endothelial cells were employed in in vitro studies, which provide the evidences that (1) LPS-induced paracellular leakage and proinflammatory cytokines release were suppressed by pretreatment with inhibitors of c-Src (PP1) or PI3K (LY294002) or by transfection with siRNAs of c-Fos; (2) fortunately, CQCQD imitated the actions of these selective inhibitions agents to inhibit LPS-induced high expressions of p-Src, p-p85α, and c-Fos, therefore attenuating paracellular leakage and proinflammatory cytokines release.

Efficacy of Glutamine-Enriched Nutrition Support for Patients With Severe Acute Pancreatitis: A Meta-Analysis

BACKGROUND

Plasma glutamine (Gln) level has been negatively correlated with the severity of severe acute pancreatitis (SAP). Although Gln is widely used today, the results of individual randomized controlled trials of Gln-enriched nutrition support for patients with SAP are conflicting.

METHODS

PubMed, EMBASE, HighWire, Cochrane Central Register of Controlled Trials, Wanfang, China Journals Full-Text Database, and the Chinese Biomedical Literature Database were searched. Literature published before June 2014 was searched. Randomized controlled trials investigating the comparison of conventional and Gln-enriched nutrition support were included; a random effect model using Rev Man 5.2 software was chosen to complete this meta-analysis. The count data were analyzed using the risk ratio (RR) and 95% confidence interval (CI), and the measurement data were analyzed using the standard mean difference or weighted mean difference and 95% CI. Heterogeneity analyses were conducted by I(2) test; publication bias analyses were conducted by Begg test.

RESULTS

Ten studies were eventually chosen for analysis, including 218 patients who received conventional methods (control group) and 215 patients who received Gln-enriched nutrition support (experimental group). Compared with the control group, Gln is helpful in elevating the albumin level, decreasing C-reaction protein (standard mean difference = 1.01, -1.89; 95% CI: 0.50 to 1.51, -3.23 to -0.56; P < .05), decreasing the incidence of infectious complication and mortality (RR = 0.62, 0.36; 95% CI: 0.46 to 0.83, 0.16 to 0.83; P < .05), and shortening the hospital stay length (weighted mean difference [WMD] = -3.89; 95% CI: -4.98 to -2.81; P < .05) without increasing expenses (WMD = -0.16; 95% CI: -1.34 to 1.02; P > .05). Intravenous infusion manifested more advantages by decreasing the incidence of infectious complications and mortality.

CONCLUSIONS

Gln-enriched nutrition support is superior to conventional methods for SAP, and intravenous infusion may be a better choice for drug administration.

Parenteral glutamine supplementation in combination with enteral nutrition improves intestinal immunity in septic rats

OBJECTIVES

The gut-associated lymphoid tissue is continuously exposed to antigens in the gut lumen and becomes the first line of defense against enteric bacteria and associated toxin. The aim of this study was to investigate the effects of parenteral glutamine (GLN) supplementation in combination with enteral nutrition (EN) on intestinal mucosal immunity in septic rats by cecal ligation and puncture (CLP).

METHODS

Male Sprague-Dawley rats were randomly assigned into four groups: A sham CLP + EN + saline group (n = 10), a sham CLP + EN + GLN group (n = 10), a CLP + EN + saline group (n = 10), and a CLP + EN + GLN group (n = 10). At 2 h after CLP or sham CLP, all rats in each of the four groups received an identical enteral nutrition solution as their base formula. Then, the rats in the sham CLP + EN + GLN group and CLP + EN + GLN group were given 0.35 g GLN/kg body weight daily for 7 d, all at the same time, via a tail vein injection; whereas those in the sham CLP + EN + saline group and CLP + EN + saline group were daily administered isovolumic sterile 0.9% saline for comparison. All rats in each of the four groups were given 290 kcal/kg body wt/d for 7 d. At the end of the seventh day after the nutritional program was finished, all rats were euthanized and the entire intestine was collected. Total Peyer's patches (PP) cell yield was counted by a hemocytometer. The percentage of PP lymphocyte subsets was analyzed by flow cytometry. The number of intestinal lamina propria IgA plasma cells was determined by the immunohistochemistry technique. The intestinal immunoglobulin A (IgA) levels were assessed by ELISA. PP apoptosis was evaluated by terminal deoxyuridine nick-end labeling.

RESULTS

The results revealed total PP cell yield, the numbers of PP lymphocyte subsets, intestinal lamina propria IgA plasma cells, and intestinal IgA levels in the CLP + EN + GLN group were significantly increased when compared with the CLP + EN + saline group (P < 0.05). On the other hand, the number of TUNEL-stained cells within PPs in the CLP + EN + GLN group was markedly decreased as compared with the CLP + EN + saline group (P < 0.05).

CONCLUSION

The results of this study show that parenteral glutamine supplementation in combination with enteral nutrition may attenuate PP apoptosis, increase PP cell yield and intestinal lamina propria IgA plasma cells, and subsequently improve intestinal mucosal immunity. Clinically, these results suggest therapeutic efforts at improving intestinal immunity may contribute to the prevention and treatment of sepsis.