Research articles

By Dr. Choudhury J , Dr. Mani UV
Corresponding Author Dr. Choudhury J
Director, Centre of Nutrition Research, Gujarat, J-902, Indraprasth Tower, Drive inroad, Ahmedabad - India 380052
Submitting Author Dr. Jayeeta Choudhury, PhD, FICN, FACN (USA)
Other Authors Dr. Mani UV
Dept Of Foods & Nutrition & WHO Collaborating Centre, The M.S University Baroda, - India


Surgical Gastrointestinal Patients (Surgical G.I Patients), Severely Malnourished (Sm) Quality of life (QOL), Enteral Nutrition (EN), Glutamine (gln), Milk-Rich EN (Control Group), Glutamine-Enriched EN (Glutamine Group), Length of Stay (LOS)

J C, UV M. Impact of Enteral Glutamine Enriched Polymeric Kitchen-Based EN on Nutritional, Functional and Quality of Life in Severely-Malnourished Postoperative Gastrointestinal Patients. WebmedCentral NUTRITION 2012;3(7):WMC003545
doi: 10.9754/journal.wmc.2012.003545

This is an open-access article distributed under the terms of the Creative Commons Attribution License(CC-BY), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Submitted on: 02 Jul 2012 05:46:09 AM GMT
Published on: 03 Jul 2012 04:43:24 PM GMT


Objective: This study investigates whether polymeric kitchen-based glutamine supplemented EN can improve nutritional, functional and quality of life (QOL) in terms of changes in body weight, early recovery from illness through decreasing hospital stay in severely malnourished G.I subjects.

Methods: Thirty-five surgical G.I subjects fulfilling the inclusion criteria, participated in this prospective, randomised study were randomly allocated to receive either polymeric kitchen-based EN containing protein from skimmed milk source(control), the most commonly used protein source or a polymeric kitchen-based EN with substrate enriched with enteral glutamine, 0.35g kg-1day-1 (study group).

Results: On admission, NRI score rated 54.15 % of the total patients as severely malnourished (Sm). Comparison in adequacies of post-operative diet intake between the glutamine-group and control group especially Sm subcategory reflected no significant difference in energy and protein intakes. Comparing baseline levels, overall a higher percentage (73.3 %) of glutamine-group patients had a significant improvement in albumin levels, (TP: 6.29 gdl-1 vs 6.23 gdl-1, Alb: 3.10 gdl-1 vs 3.04 gdl-1) with a significant tendency for weight gain (1.36 Kg vs (-) 1.5 Kg) and a shorter length of stay (LOS) by 2.3days compared to control group. Further, with significant improvement in enteral diet intake postoperatively, Sm subcategory of both the groups, especially study group patients elucidated better improvement in the protein status (TP: 5.91 gdl-1 vs 5.64 gdl-1, Alb: 3.03 gdl-1 vs 2.66 gdl-1) as compared to their controls (TP: 5.62 gdl-1 vs 5.44 gdl-1, Alb: 2.83 gdl-1 vs 2.67 gdl-1). Even Sm subcategory in both the study groups recorded a significant weight gain (3.4 % vs 2.2 %) shorter LOS by 2.1days.

Conclusion: Inexpensive polymeric kitchen-based glutamine–enriched tube feed supplement produces positive biochemical and clinical effects even in severely-malnourished surgical G.I patients. We speculate that positive energy balance, and subsequent substrate enrichment with gln might have acted as a benefit for the patients with malnutrition or nutritional depletion and thereby an indicated improvement.


Pre-existing malnutrition has been shown to be a major clinical problem in surgical patients and is often associated with poor post-operative outcome [1] with adding burden to the health care extending hospital stay. Thus, when a patient is sure to undergo surgery, prompt attention to their nutritional status is a primary task [2] so as to fortify the demands of the surgery. Specifically with regard to the enteral feeds, there have been continuous attempts to improve the quality of feeds based on the new information available in imparting good health. In this regard, glutamine (gln) is recently recognised as a conditionally essential aminoacid and treatment with it has attracted greater attention in the management of G.I diseases. It serves as preferred oxidative substrate for enterocyte and may have a vital role in the maintenance of intestinal integrity and function. It is usually adequately synthesized in the body but plasma and cellular concentrations fall rapidly after surgery. The G.I tract has markedly increased gln consumption in the stressed state and may therefore, play a role in modulating the protein catabolic response to injury. Traditional nutrition support therapies contain very little gln. Further, as the cost of treatment with commercial feeds are much higher, research studies were also directed to the area of kitchen based foods formulated using the newer nutritional information e.g., functional foods immunomodulator etc. These facts acted as stimulus to undertake the present study. We made use of milk the most commonly used protein and gln rich source available in hospital practice. Present study is designed not to show superiority of kitchen based EN over commercial formula but to compare its efficacy and effect of a glutamine-enriched EN diet in overall functional, nutritional and quality of life (QOL) in terms of changes in body weight, LOS in severely malnourished postoperative G.I patients.

Patients and Methods:

1. Inclusion of Patients and Study Protocol:
Patients 17 to 70 years age groups scheduled for G.I surgical procedures were eligible for the study. They were candidates for post-operative nutrition support and were expected to require nutrition for >7 d. Exclusion criteria were any one of the following: (1) co-existing disease which has a metabolic component such as IDDM (2) cardiac disease (class III & IV), (3) renal disease, and (4) female subjects with confirmed pregnancies. The investigation was initiated after ethics committee approval of the study protocol. On admission, anthropometry, biochemical, dietary assessments were done thereby body mass index (BMI) [3], nutritional risk index (NRI) [4] was calculated and subcategories were identified as severely malnourished (Sm), Mild-moderately malnourished (Mm), Well-nourished (Wn) especially to study the impact of supplementation on the nutritional status of the ‘severely malnourished’ subjects of the respective control and study groups.

2. Kitchen-based Enteral Immunonutrition formula and Nutrition Support:
The patients were randomly allocated to a control or a glutamine supplemented (study group) EN diets. Both diets were polymeric kitchen-based and contained good biological value protein from milk source. The control EN diet provided per litre 21 % protein, 30 % fat and 58 % carbohydrate with calorie density of 1Kcal ml-1. The glutamine-enriched polymeric kitchen based milk supplemented (glutamine group) same EN diet as above with 0.35g kg-1day-1 enteral  glutamine in addition.  Enteral access route, gastric or jejunal was instigated by the concerned clinician based on clinical assessment of the intestinal function. Patients were kept either on TPN followed by EN or directly into EN. Supplementation of the feeding formulas was done day 3 to day 12 on an average postoperatively with calorie needs estimated using Harris- Benedict [5] equation. The initial rate of delivery was 50ml hrly-1 full strength EN feed as a continuous infusion with 6 hours rest at night thereby gradually increasing step wise to a full intake. Nutrition support was continued for 10 d or until the subject was able to consume as oral diet. During this build-up period, tubes were aspirated every 2 hours and nutrition intake, feeding tolerance were monitored daily.

3. Statistical Analysis:
All parametric data were expressed as means (SD). Comparison between groups was made using students – t test or Mann Whitney’s U test for qualitative data [6]. A p value of 0.05 or less was taken to signify a statistically significant difference.


Thirty-five patients [controls and study groups] age range (17-70y) were enrolled into the study and consent was obtained. Overall the upper G.I diseases composed of 65.7 %, lower G.I diseases 8.57 % and 25.7 % as miscellaneous group {Table-1}. We performed the study in this group of patients because they relatively represented a homogenous group of patients with age, diseased type almost matched and all of them needed to undergo gastrointestinal surgical procedures. At admission, 30.9 % of the total subjects on admission revealed with weight loss more than 10 % of UBW and total protein, serum albumin levels for both the groups were at risk level. NRI score rated 54.15% of the total enrolled patients (n = 35) as ‘severely malnourished’(Sm) (n = 19) {Table-2}. In evaluating adequacy in nutritional intake, the average preoperative intake of all major nutrients was significantly low for control group (p<0.05) whereas, calorie intake was adequate by glutamine-group, but protein intake was found to be significantly low (p < 0.05) in both groups as compared to their requirements. Further, a significant low intake of protein in all subcategories in control group was also noted and the energy intake was found to be lower in Sm subcategory than the required amount. However, the calorie, carbohydrate intakes were adequate whereas, the protein intake was found to be lower in all the subcategories in glutamine-group and was significantly lower in Mm subcategory (p < 0.05) compared to their requirement. Although during postoperative stage supplementation was done either through transnasal or enterostomy tubes but postoperatively in general, both calorie and protein intake by glutamine-group was better as compared to their requirement whereas, the protein intake was significantly low in controls (p < 0.05). Further, the macronutrient intake by the subcategories of glutamine-group was found to be adequate as compared to their requirements. In case of control group, the Sm subcategory had significantly lower intake of energy (p < 0.05) as compared to their requirements. On an average, all the three subcategories of control group had significantly low protein intake as compared to their requirement (p < 0.05). Moreover, the data from the table also indicate energy intake (1817.2 Kcal vs 1530.4 Kcal) in control group was much better whereas intake was lower in glutamine- group (1766.0 Kcal vs 1909.0 Kcal) in the post-operative EN stage as compared to the pre-operative stage. However, overall protein intake was found to be significantly higher by both the study and control groups and even by the respective subcategories in post-operative EN stage as compared to pre-operative stage (p < 0.05) {Table-3}. Comparison in adequacies of post-operative intake between the glutamine-group and control group further reflected that there is no significant difference in energy and protein intakes. [Mann Whitney U-test]. Similar picture could be noted for Sm subcategory of both the groups. However, the reasons for decreased intake may be due to feeding related complications. ETF commonly causes G.I symptoms in feed related complications. Nausea occurs up to 10-20 % of patients [7], diarrhoea occurs up to 30 % patients in medical or surgical wards [8]. Abdominal bloating and cramps from delayed gastric emptying are also common [9]. Our study also detected complaints of diarrhoea (glutamine-group: 40.0%; control: 35%) and abdominal distension with a lesser frequency in the study group. Most of the laboratory tests showed no significant improvement between the groups. A slight improvement in post-operative levels of protein status was noted in glutamine-group (TP: 6.29 gdl-1 vs 6.23 gdl-1, Alb: 3.10 gdl-1 vs 3.04 gdl-1) whereas, control group had marked improvement (TP: 6.00 gdl-1 vs 5.82 gdl-1, Alb: EnM: 3.1.0 gdl-1 vs 2.97 gdl-1) as compared to admission {Table- 4(a)}. Further, with significant improvement in EN intake postoperatively by Sm subcategory of both the groups, study group patients elucidated better improvement in the protein status (TP: 5.91 gdl-1 vs 5.64 gdl-1, Alb: 3.03 gdl-1 vs 2.66 gdl-1) as compared to the control (TP: 5.62 gdl-1 vs 5.44 gdl-1, Alb: 2.83 gdl-1 vs 2.67 gdl-1) group {Table- 4(b)}.A significant weight gain (1.36Kg) was observed in glutamine-group (p < 0.05) during discharge as compared to the weight on admission whereas controls registered a significant mean weight loss of 1.50 Kg (p < 0.001). Moreover, only Sm subcategory in both the study groups recorded a significant weight increase (glutamine-group 2.08 Kg, control: 1.0 Kg) at the time of discharge as compared to the weight on admission (p < 0.05) {Table-5}. With equal days of pre-operative stay controls had longer total stay as compared to study group by 2.3 d. Further, Mm subcategory in control group and Wn subcategory of study group had a longer duration of hospital stay as compared to their respective two subgroups in the study and control groups. Comparison between Sm-subcategory of both the groups clearly reflected that even with almost similar pre-operative stay (3.1d vs 2.2 d) total stay was shorter in glutamine- group (13.7 vs 15.8 d) as compared to the control group {Table-6}.


The present randomised study describes the therapeutic efficacy and positive benefits of specialised nutrition support as well as overall economic benefit of good quality protein in nutritional depleted surgical G.I patients due to underlying disease condition. Findings of recent report describes that if malnourished subjects undergoing elective major procedures if adequately fed for at 7-10days [10] or even with IED for 5-7days pre-operatively appears to improve clinical outcome. [11] However, we could not supplement the subjects with preoperatively because of their unwillingness for longer hospital stay as it might add total cost of treatment. We found that a greater percentage (73.3 %) of patients in glutamine-group had an upward trend in albumin levels as compared to 54.1 % patients in control group. Even though there was no significant difference in improvement in levels between the two groups, but a trend for improvement in the levels of total protein and albumin was seen especially in Sm patients of glutamine-group. This also draws attention to several aspects about protein metabolism in the context we speculate that through positive energy balance, additional supplementation of gln might have acted as a benefit for a positive balance in the patients with malnutrition or depletion and thereby an improvement in protein status could be noted. Moreover, overall a significant weight gain (1.36 Kg) was noted in glutamine-group as compared to significant weight loss (1.50 Kg) in control group. This postoperative weight loss (a mean of 1.8 kg in patients receiving intravenous fluids) is acceptable as short-term under nutrition do not complicate convalescence after major surgery. [12] It is interesting to note that Sm subcategory of both the groups had significant weight gain compared to the time of admission and the increase was more in study group (4.2 %) as compared to control (2.2 %) though there was no significant difference between the groups. With respect to total stay, with almost equal days of EN supplementation, total hospital stay was 2.3 days shorter in glutamine-group with immunomodulation nutrition support as compared to control group. Moreover, Sm category of the study group had 2.1 days shorter stay compared to controls. This matches with the finding that gln supplementation reduces significantly LOS in surgical patients. [13, 14] Thus all above findings parallel recent studies that describe economic advantage of a significantly decreased hospital stay with the provision of specialised nutrition support. [15] Though statistical significant results were not obtained when comparing between the groups, but glutamine-enriched EN appears to be well tolerated and appears to be promising in improving the nutritional, functional and QOL in severely- malnourished post-surgical G.I patients. Our analysis suggests that substrate enriched with gln appears to provide therapeutic advantage.


This study pertains to a small number (n =18) of severely-malnourished patients of the total surgical G.I patients (n =35) enrolled in this study supplemented with low cost gln-supplemented milk rich EN. It is clear that malnourished surgical patients can also recover nutritionally, functionally, and QOL from simple, inexpensive kitchen based enteral immunonutrition supplement. Moreover, shorter hospital stays markedly diminish medical costs to be incurred by the patients. This economic implication is surely an added advantage for the populations of lower socioeconomic surgical G.I group.


The authors gratefully acknowledge the cooperation and support rendered by the hospital (names are not mentioned due to ethical reasons) authorities in carrying out this study. It is a own fund study by Dr. Jayeeta Choudhury


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Source(s) of Funding

Own fund by Dr. Jayeeta Choudhury

Competing Interests



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