EAL

NNNS: Polyols (2010)

Citation:

Study Design:

Class:

- Click here for explanation of classification scheme.

Quality Rating:

Research Purpose:

To determine the effects of low doses of lactitol on selected bacteria, pH and SCFA content in fecal specimens from healthy adults.

Inclusion Criteria:

Healthy
Non-vegetarian
Naive consumers of pre- and probiotic products (in other words, unfamiliar with the technical or scientific aspects of these products).

Exclusion Criteria:

History of gastrointestinal or metabolic disorders
Subject to dietary restrictions, prescribed diets or supplemental fiber intake
Had taken antibiotics, steroids or other drugs in the six months prior to the study
Vegetarian.

Description of Study Protocol:

Recruitment

Subjects were recruited from the student body of the University of Salford by publicity.

Design

Randomized controlled trial.

Blinding Used

The study was double-blinded; neither researchers nor subjects were aware of the group to which subjects were assigned
Chocolate bars were coded by manufacturer; only the manufacturer was aware of the amount of lactitol contained in the bars.

Intervention

Subjects were randomized to one of three groups to receive either:
- 0.0g lactitol per day for seven days
- 5.0g lactitol per day for seven days
- 10.0g lactitol per day for seven days
Subjects were asked to adhere to the following restrictions 24 hours prior to the study period:
- Intake of milk and fruit juice was to be limited to 300ml per day
- No sugar-free low-calorie products were to be consumed
- Subjects' adherence was monitored at each lab visit
Lactitol was supplied by PURAC Biochem BV, the Netherlands, in the form of 25g chocolate bars
- Bars were divided into three groups containing 10g total sweetener as either 10:0, 5:5 or 0:10 sucrose:lactitol
- Bars were divided into two pieces and subjects were asked to consume one chocolate bar per day for seven days, taking one piece in the morning and one piece in the afternoon
Fecal samples were supplied by subjects at baseline on the morning prior to first consumption of the test product and on day seven following consumption of the final test product
Fecal samples were stored under anaerobic conditions and were analyzed using standard laboratory testing procedures
Subjects were provided with standardized forms to record gastrointestinal symptoms and laxation data during the study period.

Statistical Analysis

Results were expressed as mean ±SEM grams wet weight feces^-1
Student's T-test was used to compare the means on day zero and day seven for each of the study groups
Wilcoxen Rank-sum test was used to compare mean total symptoms in the three study groups.

Data Collection Summary:

Timing of Measurements

Measurements were taken at baseline (day one of the study, prior to consumption of the test product) and at day seven (after consumption of the final test product).

Dependent Variables

Variable One: Total anaerobes (brain-heart infusion blood agar used for lab testing)
Variable Two: Total aerobes (brain-heart infusion blood agar used for lab testing)
Variable Three: Enterobacteria (culturemedia. MacConkey agar #3 used for lab testing)
Variable Four: Bifidobacteria (LAMVAB agar used for lab testing)
Variable Five: Lactobacilli (LAMVAB agar used for lab testing)
Variable Six: Fecal pH (fecal suspensions were prepared in 10ml sterile water and pH was measured with a glass pH electrode)
Variable Seven: Short chain fatty acids [SCFA] (measured by gas chromatography)
Variable Eight: Gastrointestinal symptomology and laxation (recorded on a standardized pre-printed form filled out by subjects during each day of the study) included nausea, colic, borborygmi, flatus, number of toilet visits and consistency of feces passed.

Independent Variables

Consumption for each of seven days of one 25g chocolate bar containing a total 10g sweetener as either 10:0 sucrose:lactitol, 5:5 sucrose:lactitol or 0:10 sucrose:lactitol.

Control Variables

All subjects following identical dietary restrictions.

Description of Actual Data Sample:

Initial N: 75 (39 male, 26 female); each of the three study groups contained 25 subjects
Age: 18 to 24 years
Anthropometrics: BMI for males, 22.80±3.01; for females 22.53±2.88
Location: University of Salford, Manchester, UK.

Summary of Results:

Key Findings

For total anaerobes, total aerobes, enterobacteriaceae, Lactobacillus and Bifodobacterium and fecal pH for subjects consuming 0g and 5.0g lactotol, there were no significant differences observed
For total anaerobes, total aerobes, enterobacteriaceae and Lactobacillus, there were no significant changes for subjects consuming 10.0g lactitol; however, there was a significant increase in Bifodobacterium (9.37 to 10.06 Log₁₀ CFU grams wet weight feces^-1; P=0.017)
Fecal pH decreased significantly for those subjects consuming 10.0g lactitol (6.82 vs. 6.48, P=0.023)
The groups consuming 0g and 5.0g lactitol experienced no changes in SCFA; however, the group consuming 10.0g lactitol experienced significant increases in propionic acid (11.7±19.25 vs. 19.3±32.69 µmol grams wet weight feces^-1; P=0.001) and butyric acid (9.1±15.57 vs. 15.4±27.53 µmol grams wet weight feces^-1; P=0.001)
Mean total gastrointestinal symptom scores were as follows: 0g lactitol group ranged from 0.44±0.26 to 1.0±0.51; 5.0g lactitol group ranged from 0.36±0.35 to 1.12±0.67; 10.0g lactitol group ranged from 0.76±0.44 to 1.96±0.71. There was a significant difference between the 0g lactitol group and the 10.0g lactitol group.
Three subjects consuming 10.0g lactitol reported moderate to severe symptoms of flatus during the first two days of the study; one subject's flatus resolved after two days and the others reported mild symptoms throughout the study. One subject experienced moderate to severe flatus and a change in stool consistency throughout the study, but not every day.

Author Conclusion:

Consumption of 10.0g lactitol per day did not result in major symptoms of gastrointestinal intolerance and elicited beneficial increases in intestinal microflora and SCFA and a decrease in intestinal pH.

Funding Source:

Industry:

Purac Biochem, Holland

Food Company:

Other:

Reviewer Comments:

There was no separate control group not receiving treatment.

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?		???
	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?	No
	2.4.	Were the subjects/patients a representative sample of the relevant population?	???
3.	Were study groups comparable?		???
	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?	???
	3.3.	Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.)	No
	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?		N/A
	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%.)	N/A
	4.3.	Were all enrolled subjects/patients (in the original sample) accounted for?	Yes
	4.4.	Were reasons for withdrawals similar across groups?	N/A
	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?	N/A
	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?	Yes
	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?	???
	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)?	???
	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?	No
10.	Is bias due to study's funding or sponsorship unlikely?		???
	10.1.	Were sources of funding and investigators' affiliations described?	Yes
	10.2.	Was the study free from apparent conflict of interest?	???