Effectiveness of Partially Hydrolyzed Guar Gum in Reducing Constipation in Long Term Care Facility Residents: A Randomized Single-Blinded Placebo-Controlled Trial

Abstract

Objectives

To assess the effectiveness of partially hydrolyzed guar gum (PHGG) in improving constipation and reducing the use of laxatives among long term care facility (LTCF) residents.

Design

A single-center, prospective, randomized, placebo-controlled, single-blinded parallel-group trial from September 2021 to November 2021.

Setting

Four LTCF in Hong Kong.

Participants

Fifty-two LTCF residents with chronic constipation (mean age: 83.9±7.6 years, male 38%).

Intervention

5g PHGG mixed with 200ml water per day for 4 weeks was given to intervention group participants. Control group received 200ml water for 4 weeks. Participants continued their usual as-needed laxative (lactulose, senna or dulcolax) on their own initiative.

Measurements

Baseline measurements included age, gender, Charlson comorbidity index, Roackwood’s Clinical Frailty Scale, body mass index and daily dietary fiber intake. Outcome measures were fecal characteristics assessed by Bristol Stool Form Scale, bowel opening frequency and laxative use frequency at baseline, first, second, third and fourth week of trial. Adverse events were measured. The study was registered on ClinicalTrial.gov; identifier: NCT 05037565.

Results

There was no significant difference in bowel frequency and stool characteristics between the treatment group and control group. However, there was a significantly lower frequency of lactulose, senna, and total laxative use in the treatment group compared with controls in the third and fourth week. There was no significant difference in adverse effects between the two groups.

Conclusion

This study showed that daily dietary fibre supplementation by using PHGG for 4 weeks in LTCF residents results in significantly less laxative use than placebo. It may be an effective way to reduce laxative dependence among older people living in LTCFs.

Introduction

Constipation is a common problem among residents living in long term care facility (LTCF). Studies have shown that around 50% of residents in LTCF have constipation and 70% of them need laxative agents (1, 2). Chronic constipation can lead to fecal impaction, incontinence and delirium. It may lead to increased frequency of hospitalizations and curtailment of normal activities of daily living (3, 4). There are multiple causes of constipation and lack of dietary fiber is one of the conditions associated with constipation in LTCF residents (5). Different types of dietary fiber supplements have been shown to be effective to increase stool frequency and decrease laxative use in LTCF residents (6, 7). Among these, water-soluble dietary fiber may be more effective in reducing constipation (8).

Partially hydrolyzed guar gum (PHGG) is a water-soluble, non-viscous, non-gelling vegetable dietary fiber derived from guar gum, a water-soluble, viscous, gelling polysaccharide found in the seeds of Cyamopsis tetragonolobus (9, 10). PHGG has been shown to be effective in relieving symptoms of irritable bowel syndrome and improving quality of life.11 It accelerates colonic transit time in patients with chronic constipation (12). It is as effective as lactulose in relieving constipation associated abdominal pain in children (13). A study involving (16) LTCF residents using pre-test and post-test design showed that PHGG could reduce constipation.14 PHGG is safe, well-tolerated and does not affect the absorption of iron or other micronutrients (15, 16).

Use of laxatives for the management of constipation is very common in LTCF residents. However, frequent or inappropriate use of laxatives may result in complications including dehydration, diarrhea, electrolyte disturbance and abdominal pain (17). Laxative use may disrupt gut microbiota and potentially increase susceptibility to Clostridium difficile infection (CDI) (18, 19). PHGG is better tolerated with lower risk of the abovementioned complications. Dietary fiber supplements through PHGG have beneficial effects on microbiota. The study by Yasukawa et al. showed that PHGG exerts prebiotic properties by increasing the concentration of intestinal short-chain fatty acid, Lactobacilli and Bifidobacterium, which indirectly reduces the risk of Clostridium difficile infection (20). Reduction in influenza infection has also been reported with PHGG administration (21).

During literature review, we could not find any randomized study examining the effectiveness of PHGG in LTCF residents. Therefore, we performed a prospective, randomized, placebo-controlled, single-blinded study to assess its effectiveness in improving constipation and reducing the use of laxative agents among LTCF residents.

Methods

This single-center, randomized, placebo-controlled, single-blinded, parallel-group study was carried out from September 2021 to November 2021. We assessed the effectiveness of PHGG in LTCF residents in improving fecal characteristics and reducing the use of laxative agents. The PHGG used was OptiFibreTM Fiber Powder (Nestle) in sachets preparation. Each sachet contains 5g of PHGG. Participants were selected from four LTCFs located in Hong Kong Southern and Western districts. Inclusion criteria were LTCF residents with age ≥ 65 who were mentally competent and able to give informed consent; They had constipation fulfilling Rome III criteria for functional constipation: 1. Must include two or more of the following: a. Straining during at least 25% of defecations; b. Lumpy or hard stools in at least 25% of defecations; c. Sensation of incomplete evacuation for at least 25% of defecations; d. Sensation of anorectal obstruction/blockage for at least 25% of defecations; e. Manual maneuvers to facilitate at least 25% of defecations (e.g., digital evacuation, support of the pelvic floor); f. Fewer than three defecations per week. 2. Loose stools are rarely present without the use of laxatives. 3. Insufficient criteria for irritable bowel syndrome (22). Exclusion criteria were previous major surgery of the abdomen, use of PHGG in the 4 months prior to the study initiation, chronic constipation due to primary organic disorder of the large bowel e.g. neoplasia, post-radiation or inflammatory strictures, patients with severe hypothyroidism; patients suffering from disease of the spinal cord, and participants having received antibiotics in the 3 months prior to the study initiation.

LTCF residents fulfilling the inclusion criteria were approached by the principal investigator. After explanation of the study protocol to residents by the principal investigator, consent forms and study leaflets were given to them. They were allowed to have one week to discuss with relatives and decide if they would like to join the study. Participants who consented were assigned by a randomization list generated using a 1:1 ratio based on balanced permuted blocks stratified by center. Participants in the treatment group received 200ml of PHGG solution daily, which was 5g of PHGG (one sachet of OptiFiberTM) mixed with 200ml of water. The mixing procedure was done by LTCF health care workers. After mixing with PHGG, the solution remained colorless, odorless and tasteless. Participants in the control group were given 200ml of water as placebo daily.

The study consisted of two periods: a 2-week run-in period and a 4-week treatment period. During the run-in period, demographic and clinical characteristics of participants were recorded. These included age, gender, comorbidities quantified by Charlson comorbidity index (23), frailty state as assessed by Rockwood’s Clinical Frailty Scale (24), body mass index. In addition, dietary intake of each participant was recorded for seven days and daily energy, protein, carbohydrate, fat and dietary fiber intake were estimated using Food Processor® Nutrition Analysis Software (ESHA Research) (25). Stool frequency, stool characteristics as assessed by Bristol Stool Form Scale (BSFS) ranging from 1 (hard stool) to 7 (liquid stool) and use of laxatives were recorded through a record diary given to participants (26). During treatment period, both groups of participants documented stool frequency, stool characteristics and use of laxatives themselves or with help from LTCF staff. Adverse reactions were recorded using a diary given to the participants to document symptoms of gastrointestinal adverse events including bloating sensation, nausea, vomiting, diarrhea, abdominal pain and increased flatulence presented within 7 days of last treatment. Participants were instructed to maintain their usual daily activities including exercise, food habits, and medication consumption. They consumed as-needed laxatives on their own wish. It was their own initiative to choose lactulose or senna or dulcolax suppository. All medications were kept by LTCF pharmacy. When they needed laxatives, they would inform the LTCF staff to give them the medications.

The primary outcome was fecal characteristics assessed by BSFS at baseline, one week, two weeks, three weeks and four weeks after intervention. BSFS of the intervention group and control group were compared. Secondary outcomes were frequency of bowel opening per week and laxative use by participants per week. The frequency of bowel opening and laxative use were recorded at baseline, one week, two weeks, three weeks and four weeks after intervention. The frequency of bowel opening and the laxative use of the intervention group and control group were compared. The frequency of laxative use was quantified as «units per week». Senokot, lactulose and dulcolax suppository were the three main laxatives used by residents in the four LTCFs. One unit of laxative was «7.5mg of senokot», «10ml lactulose» or «10mg of dulcolax suppository».

Based on previous data on the use of PHGG in adults with a 30% difference in BSFS between the intervention and control groups, we calculated a required sample size of 42 patients to achieve a statistical significance level of 0.05 with 80% power for 30% post-treatment difference in BSFS between intervention and control group (20). Assuming a 20% drop out rate, a sample size of 52 patients (26 participants in each arm) was proposed. Continuous variables were expressed as mean ± standard deviation of the mean (SD). All statistical tests were two-tailed, at the 0.05 significance level; and all p-values were rounded to three decimal places. Stool characteristics, fecal frequency and the laxatives use of the two groups were compared using independent t-test. Fisher exact test was used to compare adverse events occurrence. Statistical analysis was conducted by the investigators. SPSS 27.0 for Windows (SPSS Inc., Chicago. IL) was used for statistical computation.

The research was approved by the Institutional Review Board of Hong Kong. The study was conducted in accordance with the Declaration of Helsinki and Good Clinical Practice and was registered on ClinicalTrials.gov; identifier: NCT 05037565.

Results

Patient population

From September 2021 to October 2021, 52 LTCF residents (mean age: 83.9±7.6 years, male 38%) were randomized. The study flow is shown in Figure 1. Half of them received PHGG and half received placebo. Baseline characteristics were similar between the 2 groups (Table 1). All participants received allocated intervention over the 4-week study period. There was no lost to follow up on day 28 and no participant discontinued the intervention.

Figure 1.

Consort diagram outlining study flow

Table 1.

Baseline characteristics of the participants

	PHGG group (n=26)*	Placebo group (n=26)*	P value†
Age	82.7±7.8	84.4±6.9	0.136
Gender (male)	10 (38)	13 (50)	0.145
Charlson Comorbidity Index	1.7±0.9	1.9±0.9	0.200
Clinical Frailty Scale	3.9±1.0	4.0±1.1	0.718
Body mass index	21.2±6.3	20.7±9.3	0.565
Daily energy intake (kcal)	1376±128	1348±112	0.385
Daily protein intake (g)	72.5±6.3	74.0±7.6	0.426
Daily carbohydrate intake (g)	173.4±12.8	176.5±25.1	0.580
Daily dietary fiber intake (g)	10.4±2.2	10.9±3.5	0.506
Daily fat intake (g)	42.9±8.9	42.2±6.7	0.750

*Data are presented as Mean+/-SD or Number (%); †Compared by Independent t-test (for continuous variable) or Chi-square test (for categorical variable)

Fecal characteristics and frequency of bowel opening (Figure 2)

Figure 2.

Fecal consistency (quantified by Bristol stool form scale) and bowel opening frequency of the two groups

There was no significant difference in BSFS at first, second, third and fourth weeks between the intervention and control groups.

There was no significant difference in frequency of bowel opening at first, second, third and fourth week between the two groups.

Frequency of laxative use (Figure 3)

Figure 3.

Fecal consistency (quantified by Bristol stool form scale) and bowel opening frequency of the two groups

*p=0.020; **p=0.009; §p=0.047; †p=0.028; ‡p=0.037; 1 unit of senna = 7.5g Senokot; 1 unit of lactulose = 10ml lactulose

There was no significant difference in frequency of lactulose use at baseline, first week and second week between the two groups. However, the frequency of lactulose use was significantly lower in the treatment group than control group in third week and fourth week.

There was no significant difference in frequency of senokot use at baseline, first week, second week and third week between the two groups. Nevertheless, the frequency of senokot use was significantly lower in the treatment group than control group in fourth week.

For dulcolax suppository, there was no significant difference in frequency of use throughout the study between the two groups.

For total laxative use, there was a significantly lower frequency in the treatment group as compared to control group in third and fourth week. There was no significant difference in total laxative use between the two groups in first and second week.

Adverse effects

No death or serious adverse event was reported. Incidence of gastrointestinal symptoms was infrequent and there was no significant difference between the two groups (Table 2).

Table 2.

Incidence of gastrointestinal adverse events

	PHGG	Placebo	P value§
Bloating	3	2	1.000
Abdominal pain	1	2	1.000
Increased flatulence	8	3	0.173

§Compared by Fisher Exact test

Discussion

This randomized single-blinded placebo-controlled trial showed there was no significant difference of PHGG with placebo in fecal characteristics as measured by BSFS. However, there was significantly less laxative use in the treatment group than control group. This finding concurs with the review by Dahl et al., which reported that fiber supplement may be effective in decreasing laxative use in LTCF residents (7). In this study, the baseline dietary fiber intake of most participants was less than 13g per day, lower than the recommended amount for men (30g per day) and women (21g per day) (27). This finding is consistent with the study by Nowson et al., which also showed low dietary fiber intake by LTCF residents (28). The low daily intake of dietary fiber may be one of the reasons for constipation and reliance on laxatives among the participants in this study at baseline. Supplementation of dietary fiber in residents with low baseline dietary fiber is effective in improving constipation (29). The low baseline dietary fiber intake of participants in this study may be a reason for the good effectiveness in the treatment group. Low daily intake of dietary fiber by LTCF residents is common and highly related to the meal prepared by LTCF.30 PHGG can be dissolved in water or any other fluid without affecting taste. This simple and convenient way of administration makes daily supplementation of dietary fiber to regular meals feasible, sustainable and may be more effective than water-insoluble dietary fiber such as wheat bran (8). PHGG is available in Public hospitals dietetic formularies and can be prescribed by physicians and dieticians in many countries. It may be an effective way to supplement dietary fiber in older adults and reduce laxative use in LTCFs.

In this study, stool consistency measured by BSFS and frequency of bowel opening of the intervention group had small but insignificant difference compared with control group. This finding is different from the study by Yasukawa et al., which showed a significant difference between the intervention and control groups.20 One possible explanation is the differences in study participants. The daily dietary fiber intake of participants in the study by Yasukawa et al was adequate and they did not require any laxative at baseline. In this study, participants had underlying constipation and required more laxatives. However, we observed a reduction in laxative use amongst the LTCF residents in the treatment group. This suggested that PHGG is effective to mitigate constipation tendency by reducing their reliance on laxatives while maintaining similar bowel opening and stool characteristics.

There are several limitations in this study. The PHGG supplementation was standardized at 5g per day in this study. Even with 5g dietary fiber supplementation, the daily fiber intake of most participants was still lower than the recommended dose. Further study to assess the effect of dietary fiber intake correction up to recommended amounts is necessary. Another limitation is that the investigators were not blinded to the treatment. Staff of LTCF assisted storage of PHGG, preparation of PHGG solution and supply of solution to participants. Close monitoring of their work was necessary to ensure smooth progression of the study and treatment was hence unavoidably unblinded. We only looked at LTCF residents in this study and the results may not be generalizable to other older people in the community.

This study showed that daily dietary fibre supplementation by using PHGG for 4 weeks in LTCF residents results in significantly less laxative use than placebo. PHGG is available in Public hospitals dietetic formularies and can be prescribed by physicians and dieticians in many countries. It may be an effective way to reduce laxative prescription in LTCFs.

Author Contributions

Study concept, design and participant recruitments: TC Chan, JKY Yuen, JKH Luk, FHW Chan. Data collection: TC Chan, VMW Yu. Analysis and interpretation of data: TC Chan, LW Chu, VMV Yu. Preparation of paper: TC Chan, JKH Luk, LW Chu, FHW Chan.

Conflict of interest

The authors declare no conflict of interest.

Ethical standard

The research was approved by the Institutional Review Board of The University of Hong Kong. The study was conducted in accordance with the Declaration of Helsinki and Good Clinical Practice.