CI: Enteral Nutrition and Fiber (2011)


Chittawatanarat K, Pokawinpudisnun P, Polbhakdee Y. Mixed fibers diet in surgical ICU septic patients. Asia Pac J Clin Nutr. 2010; 19 (4): 458-464.

PubMed ID: 21147705
Study Design:
Randomized Controlled Trial
A - Click here for explanation of classification scheme.
Quality Rating:
Positive POSITIVE: See Quality Criteria Checklist below.
Research Purpose:

Demonstrate effects of enteral formula containing mixed (soluble and insoluble) fiber on critically-ill patients who needed antibiotics and were hospitalized in a general ICU.

Inclusion Criteria:
  • Septic patients who received broad spectrum antibiotics and EN
  • Hospitalized in the general ICU during the period of February 2007 to November 2008.


Exclusion Criteria:
  • Hemodynamic instability
  • Bowel obstruction, hemorrhage, ileus
  • Acute pancreatitis
  • Post-endoscopy under 24 hours
  • Ischemic bowel
  • Inflammatory bowel, ulcerative colitis, Chron's disease
  • Enteric fistula
  • Malabsorptive syndrome
  • Eligible patients who did not sign informed consent.
Description of Study Protocol:
  • Recruitment: Patients in a six-bed ICU during the 19-month study period, who met inclusion criteria and signed informed consent
  • Design: RCT (randomization scheme not described)
  • Blinding used: Double-blind trial.


  • Intervention Group received EN formula containing mixed fiber (Nutren Fibre®)
  • Control Group received standard EN formula without fiber (Nutren Optimum®)
  • All patients received formula for five or more days.

Statistical Analysis

  • Mean and standard deviation in normal distribution continuous data
  • X2 or Fisher's exact test for analysis of categorical data
  • Student's T-test for variables with normal distribution
  • Mann-Whitney U-test for variables without normal distribution.
Data Collection Summary:
  • Timing of measurements: Recorded each incidence of diarrhea
  • Dependent variables: Diarrhea (score according to Hart and Dobb method) 
  • Independent variables: Type of EN formula (with or without fiber)
  • Control variables: Medications known to cause diarrhea prohibited in all patients.
Description of Actual Data Sample:
  • Initial N: 34 (12 males, 22 females)
  • Attrition: Final N=31 (one died in the Fiber Group and two died in the Control Group)
  • Age: Mean, 50 years (P=0.68 between groups)
  • Ethnicity: Not described.

Other Relevant Demographics

  • Mean APACHE score (P=0.83)
    • Fiber: 19.8±4.2 (95% CI, 17.6-22.0)
    • No fiber: 22.2±6.6 (95% CI, 16.8-23.6).
  • Albumin (P=0.37)
    • Fiber: 3.1±0.8 (95% CI, 2.7-3.5)
    • No fiber: 2.9±0.9 (95% CI, 2.4-3.3).
  • No difference by group in energy intake.


No differences in groups by weight (P=0.69).


Chiang Mai University, Thailand.


Summary of Results:

 Key Findings


Fiber Group

No Fiber Group

Statistical Significance of Group Difference

Diarrhea Score >12

4/17 (23.5%)

8/17 (47.1%)


Diarrhea Score (mean)




Overall Incidence of Diarrhea Density per 100 Patient-Fed Days



IRR, 0.45 (95% CI, 0.2-0.9; P=0.01)

ICU LOS Days (mean, range)
16.8 (6-37)
25.5 (11-50)
Hospital LOS Days (mean, range)
30.9 (6-120)
36.1 (15-61)

Other Findings

Repeated-measures model confirmed that diarrhea scores were statistically different: Coefficient of Fiber Group was -3.03 (95% CI, -5.0 to -0.9; P=0.01).

Author Conclusion:

Formula containing mixed fiber reduced diarrhea scores in critically-ill septic patients who required broad spectrum antibiotics.

Funding Source:
Nestle donated both EN formulas
Pharmaceutical/Dietary Supplement Company:
University/Hospital: Chiang Mai University, Thailand
In-Kind support reported by Industry: Yes
Reviewer Comments:
Quality Criteria Checklist: Primary Research
Relevance Questions
  1. Would implementing the studied intervention or procedure (if found successful) result in improved outcomes for the patients/clients/population group? (Not Applicable for some epidemiological studies) Yes
  2. Did the authors study an outcome (dependent variable) or topic that the patients/clients/population group would care about? Yes
  3. Is the focus of the intervention or procedure (independent variable) or topic of study a common issue of concern to dieteticspractice? Yes
  4. Is the intervention or procedure feasible? (NA for some epidemiological studies) Yes
Validity Questions
1. Was the research question clearly stated? Yes
  1.1. Was (were) the specific intervention(s) or procedure(s) [independent variable(s)] identified? Yes
  1.2. Was (were) the outcome(s) [dependent variable(s)] clearly indicated? Yes
  1.3. Were the target population and setting specified? Yes
2. Was the selection of study subjects/patients free from bias? Yes
  2.1. Were inclusion/exclusion criteria specified (e.g., risk, point in disease progression, diagnostic or prognosis criteria), and with sufficient detail and without omitting criteria critical to the study? Yes
  2.2. Were criteria applied equally to all study groups? Yes
  2.3. Were health, demographics, and other characteristics of subjects described? Yes
  2.4. Were the subjects/patients a representative sample of the relevant population? Yes
3. Were study groups comparable? Yes
  3.1. Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT) No
  3.2. Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline? Yes
  3.3. Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.) Yes
  3.4. If cohort study or cross-sectional study, were groups comparable on important confounding factors and/or were preexisting differences accounted for by using appropriate adjustments in statistical analysis? N/A
  3.5. If case control study, were potential confounding factors comparable for cases and controls? (If case series or trial with subjects serving as own control, this criterion is not applicable.) N/A
  3.6. If diagnostic test, was there an independent blind comparison with an appropriate reference standard (e.g., "gold standard")? N/A
4. Was method of handling withdrawals described? Yes
  4.1. Were follow-up methods described and the same for all groups? Yes
  4.2. Was the number, characteristics of withdrawals (i.e., dropouts, lost to follow up, attrition rate) and/or response rate (cross-sectional studies) described for each group? (Follow up goal for a strong study is 80%.) Yes
  4.3. Were all enrolled subjects/patients (in the original sample) accounted for? Yes
  4.4. Were reasons for withdrawals similar across groups? Yes
  4.5. If diagnostic test, was decision to perform reference test not dependent on results of test under study? N/A
5. Was blinding used to prevent introduction of bias? Yes
  5.1. In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate? Yes
  5.2. Were data collectors blinded for outcomes assessment? (If outcome is measured using an objective test, such as a lab value, this criterion is assumed to be met.) Yes
  5.3. In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded? N/A
  5.4. In case control study, was case definition explicit and case ascertainment not influenced by exposure status? N/A
  5.5. In diagnostic study, were test results blinded to patient history and other test results? N/A
6. Were intervention/therapeutic regimens/exposure factor or procedure and any comparison(s) described in detail? Were interveningfactors described? Yes
  6.1. In RCT or other intervention trial, were protocols described for all regimens studied? Yes
  6.2. In observational study, were interventions, study settings, and clinicians/provider described? N/A
  6.3. Was the intensity and duration of the intervention or exposure factor sufficient to produce a meaningful effect? Yes
  6.4. Was the amount of exposure and, if relevant, subject/patient compliance measured? Yes
  6.5. Were co-interventions (e.g., ancillary treatments, other therapies) described? Yes
  6.6. Were extra or unplanned treatments described? N/A
  6.7. Was the information for 6.4, 6.5, and 6.6 assessed the same way for all groups? N/A
  6.8. In diagnostic study, were details of test administration and replication sufficient? N/A
7. Were outcomes clearly defined and the measurements valid and reliable? Yes
  7.1. Were primary and secondary endpoints described and relevant to the question? Yes
  7.2. Were nutrition measures appropriate to question and outcomes of concern? Yes
  7.3. Was the period of follow-up long enough for important outcome(s) to occur? Yes
  7.4. Were the observations and measurements based on standard, valid, and reliable data collection instruments/tests/procedures? Yes
  7.5. Was the measurement of effect at an appropriate level of precision? Yes
  7.6. Were other factors accounted for (measured) that could affect outcomes? Yes
  7.7. Were the measurements conducted consistently across groups? Yes
8. Was the statistical analysis appropriate for the study design and type of outcome indicators? Yes
  8.1. Were statistical analyses adequately described and the results reported appropriately? Yes
  8.2. Were correct statistical tests used and assumptions of test not violated? Yes
  8.3. Were statistics reported with levels of significance and/or confidence intervals? Yes
  8.4. Was "intent to treat" analysis of outcomes done (and as appropriate, was there an analysis of outcomes for those maximally exposed or a dose-response analysis)? Yes
  8.5. Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)? Yes
  8.6. Was clinical significance as well as statistical significance reported? Yes
  8.7. If negative findings, was a power calculation reported to address type 2 error? N/A
9. Are conclusions supported by results with biases and limitations taken into consideration? Yes
  9.1. Is there a discussion of findings? Yes
  9.2. Are biases and study limitations identified and discussed? Yes
10. Is bias due to study's funding or sponsorship unlikely? Yes
  10.1. Were sources of funding and investigators' affiliations described? Yes
  10.2. Was the study free from apparent conflict of interest? Yes