Nutritional pharmacology and malignant disease: a therapeutic modality in patients with cancer

Effect of enteral immunonutrition compared with enteral nutrition on surgical wound infection, immune and inflammatory factors, serum proteins, and cellular immunity in subjects with gastric cancer undergoing a total gastrectomy: A meta-analysis

We performed a meta-analysis to evaluate the effect of enteral immunonutrition compared with enteral nutrition on surgical wound infection, immune and inflammatory factors, serum proteins, and cellular immunity in subjects with gastric cancer undergoing a total gastrectomy. A systematic literature search up to November 2021 was done, and 10 studies included 1056 subjects with gastric cancer undergoing a total gastrectomy at the start of the study: 505 of them were provided with enteral immunonutrition, and 551 were enteral nutrition. They were reporting relationships about the effect of enteral immunonutrition compared with enteral nutrition on surgical wound infection, immune and inflammatory factors, serum proteins, and cellular immunity in subjects with gastric cancer undergoing a total gastrectomy. We calculated the odds ratio (OR) or mean difference (MD) with 95% confidence intervals (CIs) to assess the effect of enteral immunonutrition compared with enteral nutrition on surgical wound infection, immune and inflammatory factors, serum proteins, and cellular immunity in subjects with gastric cancer undergoing a total gastrectomy using the dichotomous or contentious method with a random or fixed-effect model. Enteral immunonutrition had no significant difference in the surgical wound infection (OR, 0.77; 95% CI, 0.50-1.19, P = .24), the infectious complication (OR, 0.72; 95% CI, .48-1.09, P = .13), the systemic inflammatory response syndrome (MD, -0.50; 95% CI, -1.40 to 0.39, P = .27), the CD8+ level (MD, 1.34; 95% CI, 0-2.68, P = .05), the CD4+ level (MD, 1.21; 95% CI, -7.65 to 10.07, P = .79), the CD4-CD8+ (MD, 0.55; 95% CI, 0-1.10, P = .05), the lymphocyte (MD, -0.77; 95% CI, -1.87 to 0.33, P = .17), and the transferrin (MD, 0.03; 95% CI, -0.01 to 0.08, P = .14) compared with enteral nutrition in subjects with gastric cancer undergoing a total gastrectomy. However, enteral immunonutrition had significantly higher proalbumin (MD, 22.15; 95% CI, 3.57-40.72, P = .02), IgM (MD, 0.47; 95% CI, 0.43-0.50, P < .001), and IgG (MD, 1.98; 95% CI, 1.08-2.89, P < .001) compared with enteral nutrition in subjects with gastric cancer undergoing a total gastrectomy. Enteral immunonutrition had no significant difference in the surgical wound infection, the infectious complication, the systemic inflammatory response syndrome, the CD8+ level, the CD4+ level, the CD4+/CD8+, the lymphocyte, and the transferrin, and had significantly higher proalbumin, IgM, and IgG compared with enteral nutrition in subjects with gastric cancer undergoing a total gastrectomy. Further studies are required to validate these findings or to affect the confidence level.

Immunonutrition in head and neck cancer: Systematic review and metanalysis of its clinical and nutritional effects

BACKGROUND AND AIMS

A systematic review was conducted to assess the effects of glutamine, arginine and omega-3 supplementation on the tolerance to treatment, nutritional status and immune function of head and neck cancer (HNC) patients undergoing chemoradiotherapy.

METHODS

Randomized clinical trials were searched in MEDLINE, EMBASE, CENTRAL, LILACS, ClinicalTrials.gov, OpenGrey and Proquest. Tolerance to treatment, nutritional status, immune function and mortality rate were the primary outcomes investigated. Secondary outcomes comprised functional status, weight loss and body composition. Risk of bias of individual studies and the overall quality of the evidence were assessed using the Cochrane and the GRADE tools, respectively.

RESULTS

Nineteen articles met the inclusion criteria and nine were included in the meta-analyses, which assessed mucositis severity, weight loss and handgrip strength. Ten studies were evaluated as high risk of bias. Glutamine supplementation has significantly reduced the risk of grade 2-4 mucositis (RR: 0.76, IC95% [0.63; 0.92], P = 0.006, I² = 0%; P = 0.792; 4 studies). Omega-3 supplementation did not show statistically significant results on weight loss (SMD: -0.042, 95% CI [-0.322; 0.238], P = 0.769, I² = 33.4%; P = 0.212; 4 studies). The overall quality of the evidence ranged from low to very low.

CONCLUSIONS

These results must be interpreted with caution due to differences between supplementations regimen, lack of methodological rigor in most studies and due to the possible role of glutamine in tumor metabolism. Studies focused on elucidating the contribution of each immunonutrient to HNC patients undergoing chemoradiotherapy deserve further investigation.

Comparing isolated soy protein with flaxseed oil vs isolated soy protein with corn oil and wheat flour with corn oil consumption on muscle catabolism, liver function, blood lipid, and sugar in burn patients: a randomized clinical trial

BACKGROUND

There is controversy regarding whether increasing isolated soy protein (ISP) with or without flaxseed oil (FO), as functional foods, would lead to reduce muscle catabolism and cachexia in burn patients.

METHODS

One hundred and eighty-eight patients were assessed for eligibility in this randomized controlled trial. Of these, seventy-three eligible patients (total burn surface area 20-50%) were randomly assigned to three groups, labeled as Control (wheat flour [WF] + corn oil [CO]), ISP + FO, and ISP + CO, to receive these nutrients for three weeks. Weight, body mass index (BMI), serum hepatic enzymes (alanine transaminase [ALT], aspartate transaminase [AST], alkaline phosphatase [ALP]), systemic inflammatory response syndrome (SIRS), 24-h urinary urea nitrogen excretion (UUN), serum creatinine, 24-h urinary creatinine (UUC) excretion, fasting blood sugar (FBS), triglyceride (TG), and cholesterol were measured.

RESULTS

Using analysis of covariance models in the intention-to-treat population (n = 73), we found that at three weeks, patients in the ISP groups had lost significantly less in weight and BMI compared to those in the control group (all P < 0.01). Nitrogen retention and serum creatinine (primary outcomes) increased significantly in the ISP groups compared with the control group. Even after controlling for potential covariates in ANCOVA models, changes in these indices were still statistically significant (P = 0.008 and P = 0.005 for nitrogen balance and serum creatinine, respectively). However, no such significant differences were found between the ISP groups. On the other hand, 24-h UUN, and UUC excretion, serum hepatic enzymes, FBS, TG, and cholesterol were not significant between the groups (P > 0.05).

CONCLUSION

ISP and FO compared to WF and CO reduced muscle catabolism and increased body weight in burn patients.

TRIAL REGISTRATION

Iranian Registry of Clinical Trials, IRCT2014051817740N1 . Registered on 27 June 2014.

Enteral immunonutrition versus enteral nutrition for gastric cancer patients undergoing a total gastrectomy: a systematic review and meta-analysis

Background

Nutrition support is a common means for patients with gastric cancer, especially for those undergoing elective surgery. Recently, enteral immunonutrition (EIN) was increasingly found to be more effective than enteral nutrition (EN) in enhancing the host immunity and eventually improving the prognosis of gastric cancer patients undergoing gastrectomy. However, the results reported were not consistent. This meta-analysis aimed to assess the impact of EIN for patients with GC on biochemical, immune indices and clinical outcomes.

Methods

Four electronical databases (Medline, EMBASE, Scopus and Cochrane library) were used to search articles in peer-reviewed, English-language journals. Mean difference (MD), Relative risk (RR), or standard mean difference (SMD) with 95% confidence interval (CI) were calculated. Heterogeneity was assessed by Cochrane Q and I² statistic combined with corresponding P-value. The analysis was carried out with RevMan 5.3.

Results

Seven studies involving 583 patients were eligible for the pooled analysis. EIN, when beyond a 7-day time-frame post-operatively (D ≥ 7), increased level of CD4⁺ (SMD = 0.99; 95% CI, 0.65–1.33; P < 0.00001), CD4⁺/ CD8⁺ (SMD = 0.34; 95% CI, 0.02–0.67; P = 0.04), the IgM (SMD = 1.15; 95% CI, 0.11–2.20; P = 0.03), the IgG (SMD = 0.98; 95% CI, 0.55–1.42; P < 0.0001), the lymphocyte (SMD = 0.69; 95% CI, 0.32–1.06; P = 0.0003), and the proalbumin (SMD = 0.73; 95% CI, 0.33–1.14; P = 0.0004). However, those increased effects were not obvious within a 7-day time-frame post-operatively (D < 7). The levels of CD8⁺ and other serum proteins except proalbumin were not improved both on D ≥ 7 and D < 7. Clinical outcomes such as systemic inflammatory response syndrone (SIRS) (MD, - 0.89 days; 95% CI, - 1.40 to - 0.39; P = 0.005), and postoperative complications (RR, 0.29; 95% CI, 0.14–0.60; P = 0.001) were significantly reduced in EIN group. Pulmonary infection and length of hospitalization (LHS) were not improved no matter what time after surgery.

Conclusions

EIN was found to improve the cellular immunity, modulate inflammatory reaction and reduce postoperative complication for GC patients undergoing radical gastrointestinal surgery. Exclusion of grey literature and non-English language studies was the key limitation in this study.

Bacterial Pneumonia in Patients with Cancer: Novel Risk Factors and Management

Bacterial pneumonias exact unacceptable morbidity on patients with cancer. Although the risk is often most pronounced among patients with treatment-induced cytopenias, the numerous contributors to life-threatening pneumonias in cancer populations range from derangements of lung architecture and swallow function to complex immune defects associated with cytotoxic therapies and graft-versus-host disease. These structural and immunologic abnormalities often make the diagnosis of pneumonia challenging in patients with cancer and impact the composition and duration of therapy. This article addresses host factors that contribute to pneumonia susceptibility, summarizes diagnostic recommendations, and reviews current guidelines for management of bacterial pneumonia in patients with cancer.

Older Patients Are Immunocompromised by Cytokine Depletion and Loss of Innate Immune Function After HIP Fracture Surgery

PURPOSE/INTRODUCTION

We have examined the immune status of elderly patients who underwent surgery for a hip fracture, an injury associated with poor postoperative outcomes, to identify specific immune defects.

METHODS

In a cohort observational study, 16 patients undergoing surgery for hip fractures had immune function evaluation prior to surgery, and then at 3 and 7 days postoperatively, using flow cytometry for phenotype and for monocyte and granulocyte phagocytic function and respiratory burst. Serum samples were stored and batch analyzed using a human cytokine 25-plex panel.

RESULTS

We report significant loss of innate immune function, related specifically to reduced granulocyte numbers by day 7 (P < .0001, flow cytometry; P < .05 white blood cells), and although granulocyte ability to take up opsonized Escherichia coli was increased (P < .05), the ability of those cells to generate a respiratory burst was reduced at days 3 and 7 (P < .05). Monocyte respiratory burst was also significantly reduced (P < .05). Serum cytokine levels indicated very poor T-cell function.

CONCLUSION

We have demonstrated that the antimicrobial immune response is profoundly reduced after surgery in elderly patients with hip fractures. The effect was sustained up to 7 days postoperatively, identifying these patients as particularly vulnerable to bacterial infections.

Effect of preoperative immunonutrition and other nutrition models on cellular immune parameters

AIM: To evaluate the effects of preoperative immunonutrition and other nutrition models on the cellular immunity parameters of patients with gastrointestinal tumors before surgical intervention. In addition, effects on postoperative complications were examined.

METHODS: Patients with gastrointestinal tumors were randomized into 3 groups. The immunonutrition group received a combination of arginine, fatty acids and nucleotides. The second and third group received normal nutrition and standard enteral nutrition, respectively. Nutrition protocols were administered for 7 d prior to the operation. Nutritional parameters, in particular prealbumin levels and lymphocyte subpopulations (CD4+, CD8+, CD16+/56+, and CD69 cells) were evaluated before and after the nutrition protocols. Groups were compared in terms of postoperative complications and duration of hospital stay.

RESULTS: Of the 42 patients who completed the study, 16 received immunonutrition, 13 received normal nutrition and 13 received standard enteral nutrition. prealbumin values were low in every group, but this parameter was improved after the nutritional protocol only in the immunonutrition group (13.64 ± 8.83 vs 15.98 ± 8.66, P = 0.037). Groups were similar in terms of CD4+, CD16+/56, and CD69+ prior to the nutritional protocol; whereas CD8+ was higher in the standard nutrition group compared to the immunonutrition group. After nutritional protocols, none of the groups had an increase in their lymphocyte subpopulations. Also, groups did not differ in terms of postoperative complications and postoperative durations of hospital stay.

CONCLUSION: Preoperative immunonutrition provided a significant increase in prealbumin levels, while it did not significantly alter T lymphocyte subpopulation counts, the rate of postoperative complications and the duration of hospital stay.

Metabolic mechanisms of tumor resistance to T cell effector function

Established tumors develop ways to elude destruction by the host immune system. Recent work has revealed that tumors can take advantage of the generation of metabolic dysregulation to inhibit immune responses. Effector T-cell functions are particularly sensitive to nutrient availability in the tumor microenvironment. In this review, we highlight experimental data supporting the importance of glucose, oxygen, tryptophan, and arginine for optimal T-cell function, and the mechanisms by which these nutrients may become depleted in the tumor microenvironment. These observations provide a conceptual framework for modulating metabolic features of the T cell-tumor interaction, toward the end of promoting more effective immune-mediated tumor destruction in vivo.

Early postoperative jejunostomy feeding with an immune modulating diet in patients undergoing resectional surgery for upper gastrointestinal cancer: A prospective, randomized, controlled, double-blind study

BACKGROUND

The provision of perioperative immune modulating enteral feeds after major surgery may result in reduced infective complications, but meta-analyses have not demonstrated a survival advantage. The aim of this study was to determine whether early postoperative immune modulating jejunostomy feeding results in reduced infective complications in patients undergoing resectional surgery for upper gastrointestinal cancer.

METHODS

A total of 120 patients undergoing resection for cancers of the pancreas, oesophagus and stomach were randomized in a double-blind manner to receive jejunostomy feeding with an immune modulating diet (Stresson-Group A) or an isonitrogenous, isocaloric feed (1250 Calories and 75 g protein/l--Nutrison High Protein-Group B) for 10-15 days. Feeding was commenced 4h postoperatively and continued for 20 h/day. The target volume (ml/h) was 25 on day 0, 50 on day 1, and 75 thereafter. Outcome measures included complications, hospital stay and mortality.

RESULTS

A total of 108 patients (54 in each group) were analysed. Feed delivery, although less than targeted, was similar in both groups. There were 6 (11%) deaths in each group. Median (IQR) postoperative hospital stay was 14.5 (12-23) days in Group A and 17.5 (13-23) days in Group B (P=0.48). A total of 24 (44%) patients in each group had infective complications (P=1.0). A total of 21 (39%) patients in Group A and 28 (52%) in Group B had non-infective complications (P=0.18). Jejunostomy-related complications occurred in 26 (48%) patients in Group A and 30 (56%) in Group B (P=0.3).

CONCLUSION

Early postoperative feeding with an immune modulating diet conferred no outcome advantage when compared with a standard feed.

Nutrition and the surgical patient: Triumphs and challenges

The understanding of the role of nutrition in the surgical patient has lead to major developments in the nutritional support of patients undergoing surgery. Reductions in morbidity by ensuring that patients receive optimal nutritional support can be achieved. Furthermore, the use of nutrients to modify immune, inflammatory and metabolic processes also offers new possibilities for reducing morbidity following major surgery. However, we are only at an embryonic stage in our understanding of how nutrients and nutrition affect the genome and this knowledge offers exciting possibilities in the future for modulating many key intracellular processes, particularly in the patient with cancer.

Altered serum transforming growth factor-beta1 and monocyte chemoattractant protein-1 levels in obstructive jaundice

Impaired immune function has long been documented in patients with obstructive jaundice, and those with jaundice due to extrahepatic biliary obstruction still experience a high rate of postoperative complications and death. Transforming growth factor-beta1 (TGFbeta1) appears to be an important regulator of both normal and pathologic conditions in the liver. Monocyte chemoattractant protein-1 (MCP-1) is an important mediator of monocyte recruitment to inflammatory sites. We hypothesize that obstructive jaundice may alter serum TGFbeta1 and MCP-1 expressions in the rat and that oral bile acid or glutamine (or both) can restore the altered serum TGFbeta1 and MCP-1 expression in rats with obstructive jaundice. Male Sprague-Dawley rats weighing 250 to 300 g were randomized to four groups (n = 10 in each group). Group 1 underwent a sham operation with oral normal saline administration. Group 2 underwent common bile duct ligation (CBDL) with oral normal saline administration. Group 3 underwent CBDL with oral bile acid replacement. Group 4 underwent CBDL with oral glutamine administration. Animals were sacrificed after 3 days (n = 5) and 7 days (n = 5), and blood samples were collected. Serum was obtained after centrifugation for measurement of TGFbeta1 and MCP-1 levels by an enzyme-linked immunosorbent assay. The serum TGFbeta1 level was significantly elevated (p = 0.006) 3 days after CBDL. Oral glutamine administration prevented this elevation, but oral bile acid replacement did not. The serum MCP-1 level showed similar changes. After 3 days of obstructive jaundice, the TGFbeta1 and MCP-1 levels were altered in the rat. Oral glutamine administration, not oral bile acid replacement, was able to prevent these alterations.

Effect of glutamine and bile acid on hepatocyte apoptosis after bile duct ligation in the rat

Apoptosis is an important process in a wide variety of biologic systems. Cholestasis, or impaired bile formation, occurs in a wide variety of human liver diseases. Retention and accumulation of toxic hydrophobic bile salts in hepatocytes may cause hepatocyte toxicity by inducing apoptosis. In addition, the translocation of bacteria and endotoxin, well documented in patients with obstructive jaundice, contribute to the induction of hepatocyte apoptosis. We hypothesized that oral bile acid replacement, glutamine administration, or both can attenuate or abolish hepatocyte apoptosis. Male Sprague-Dawley rats weighing 250 to 300 g were randomized to four groups (10 in each group). Group 1 underwent a sham operation and was simultaneously treated with normal saline. Group 2 underwent common bile duct (CBD) ligation and was simultaneously treated with normal saline. Group 3 underwent CBD ligation and was simultaneously treated with oral glutamine. Group 4 underwent CBD ligation and was simultaneously treated with oral bile acid replacement. After 3 days (n = 5) and 7 days (n = 5), liver tissues were harvested for histopathologic analysis and apoptosis measurements. When compared with the sham operation group, significantly increased hepatocyte apoptosis and ductular proliferation occurred after CBD ligation for either 3 or 7 days. After administration of either glutamine or bile acid, the increased hepatocyte apoptosis and ductular proliferation after CBD ligation for 3 days were significantly diminished. However, both failed to diminish the changes after CBD ligation for 7 days. Significantly increased hepatocyte apoptosis and ductular proliferation occurred after CBD ligation. The administration of either glutamine or bile acid effectively diminished the hepatocyte apoptosis and ductular proliferation after CBD ligation for 3 days, whereas both failed to show the same effect after CBD ligation for 7 days.

Immunonutrition

Has clinical potential, but much more research is required

Obstructive jaundice alters proliferating cell nuclear antigen expression in rat small intestine

Translocation of bacteria and endotoxin has long been documented in obstructive jaundice, and altered intestinal barrier function is considered to be one of the important mechanisms for this phenomenon. Proliferating cell nuclear antigen (PCNA), also known as cyclin, is an auxiliary protein of DNA polymerase-delta, and the level of synthesis correlates directly with rates of cellular proliferation and DNA synthesis. This study was designed with the aim of evaluating the effect of obstructive jaundice on PCNA expression in small bowel epithelium. Male Sprague-Dawley rats were randomized to four groups. Group A (n = 10, control group) underwent a sham operation. Group B (n = 9, obstructive jaundice group for 1 week) underwent common bile duct ligation. Group C (n = 8, obstructive jaundice group for 2 weeks) underwent common bile duct ligation. Group D (n = 8, obstructive jaundice group for 2 weeks) underwent common bile duct ligation with oral glutamine intake. After periods of 7 days and 2 weeks, segments of small bowel were harvested from groups A & B and groups C & D, respectively. Nuclear immunohistochemical expression of PCNA in small bowel was evaluated. The PCNA-labeling index [(PCNA-positive cells/500 cells) x 100] was quantified. Comparisons among the four groups were performed. The PCNA-labeling index in small bowel of group B was significantly higher than that of group A (29.0% vs 21.2%, p = 0.001). After 2 weeks of common bile duct ligation, the PCNA-labeling index in small bowel of group C was significantly lower than that of group A (19.4% vs 21.2%, p = 0.045). With oral glutamine intake daily, the PCNA-labeling index in small bowel of Group D was restored and was significantly higher than that of group A (24.5% vs 21.2%, p = 0.002). Obstructive jaundice for 1 week upgraded PCNA expression in rat small intestine. PCNA expression in rat small intestine later became depressed after obstructive jaundice for 2 weeks. Oral glutamine intake daily could effectively restore the PCNA expression in small bowel of rats subjected to obstructive jaundice for 2 weeks.

Role of arginine, taurine and homocysteine in cardiovascular diseases

Arginine, taurine and homocysteine are amino acids which have been shown to affect the risk factors of cardiovascular diseases in humans. Arginine and taurine may protect against cardiovascular diseases while homocysteine may be a risk factor for them. Both arginine and taurine seem to lower blood pressure, arginine may also inhibit atherogenesis, and taurine may have antioxidant properties. However, the evidence of the beneficial effects of arginine and taurine supplementation from human studies is insufficient. Elevated levels of plasma homocysteine may be associated with atherosclerotic and thromboembolic cardiovascular diseases. Supplementation with folic acid seems to be effective in reducing hyperhomocysteinaemia, but there is an insufficient number of studies showing that lowering of homocysteine levels with vitamin supplementation will reduce the risk of cardiovascular diseases. In conclusion, further research is needed to determine the optimal levels for taurine and arginine in the human diet in order to decrease the risk factors for cardiovascular diseases, and to whom supplementation with folic acid should possibly be recommended to reduce hyperhomocysteinaemia. Even though the use of arginine and taurine supplements to reduce cardiovascular risk factors is an interesting possibility, the reported health-promoting effects and the safety of such a supplementation should first be confirmed.

Nutritional and metabolic aspects of gastrointestinal cancer

The profound impact of nutrition and nutritional support on the development and clinical outcome of gastrointestinal cancer is undeniable. However, scientific investigation into this area is recent, and many questions remain unanswered. While the importance of 'good nutrition' is unchallenged, details relating to which patients should receive nutritional support, when they should receive it, and what type of support they should receive are not known. Recent prospective randomized clinical trials and meta-analysis have provided conflicting results. This review summarizes the results of the published studies that have addressed these issues, and provides specifics regarding the current role of nutritional support in clinical care, and the prospects for future research.

Enteral nutritional supplementation with key nutrients in patients with critical illness and cancer: a meta-analysis of randomized controlled clinical trials

OBJECTIVE

To conduct a meta-analysis of 11 randomized controlled trials comparing enteral nutritional support supplemented with key nutrients versus standard enteral nutritional support to determine effects on morbidity and mortality rates and hospital stay.

BACKGROUND DATA

Recent studies have shown that malnutrition occurs in up to 30% of patients undergoing gastrointestinal surgery, resulting in an increased risk of postoperative complications and death. With the realization that key nutrients can modulate inflammatory, metabolic, and immune processes, enteral nutritional regimens (supplemented with large amounts of key nutrients) have been developed for clinical use.

METHODS

Eleven prospective, randomized controlled trials evaluating 1009 patients treated with combinations of key nutrients (Impact, Immun-Aid) were evaluated. Outcome measures examined were the incidences of pneumonia, infectious complications, and death, and length of hospital stay. Meta-analyses were undertaken to obtain the odds ratio and 95% confidence interval for incidences of infectious complications, pneumonia, and death, and the weighted mean difference and 95% confidence interval for length of hospital stay.

RESULTS

The provision of nutritional support supplemented with key nutrients to patients with critical illness resulted in a decrease in infectious complications when compared with patients receiving standard nutritional support and a significant reduction in overall hospital stay. Similar results were documented in patients with gastrointestinal cancer. However, there were no differences between patient groups for either pneumonia or death.

CONCLUSIONS

This meta-analysis has demonstrated that nutritional support supplemented with key nutrients results in a significant reduction in the risk of developing infectious complications and reduces the overall hospital stay in patients with critical illness and in patients with gastrointestinal cancer. However, there is no effect on death. These data have important implications for the management of such patients.

The value of peri-operative nutrition in the sick patient

In summary, therefore, the provision of TPN to malnourished patients in the pre-operative period reduces the incidence of post-operative complications, but does not affect post-operative mortality. It is likely that the provision of nutrition by the enteral route is as effective as that by the parenteral route, and may have the extra benefit of resulting in a reduction in infectious complications when compared with patients receiving TPN. Furthermore, the use of enteral nutritional support in the post-operative period may also reduce both septic and major complications, but does not alter mortality. The use of specific combinations of nutrients appears to offer the greatest promise in the use of peri-operative nutritional support. The initial studies reported to date demonstrate reductions in post-operative morbidity, but again there are no benefits on mortality. However, further studies to determine the optimal combinations of nutrients for use in patients in the peri-operative period are urgently required.