Pilot randomised controlled trial evaluating feasibility, safety and adherence to psyllium husk in peritoneal dialysis: The FIBRE-PD trial

Welcome to AudioScholar. Today we're covering "Pilot randomised controlled trial evaluating feasibility, safety and adherence to psyllium husk in peritoneal dialysis: The FIBRE-PD trial," published in *Peritoneal Dialysis International: Journal of the International Society for Peritoneal Dialysis*.

For our patients on peritoneal dialysis, or PD, constipation is more than just an uncomfortable nuisance. It's a common and clinically significant problem that can lead to serious complications. The causes are multifactorial—fluid restrictions, low dietary fiber, and medications like phosphate binders all play a role. When a patient becomes constipated, it can obstruct dialysate drainage, cause poor fluid removal, lead to catheter migration, and even increase the risk of peritonitis. The standard approach is often to prescribe osmotic laxatives, like macrogol, but these can be poorly tolerated, contribute to a high pill and sachet burden, and adherence is often suboptimal. This leaves a clear need for alternative strategies. This paper investigates one such alternative: psyllium husk, a natural, low-cost, bulk-forming fiber supplement. The FIBRE-PD trial was designed as a pilot study to see if using psyllium husk is a feasible, safe, and acceptable option for patients on PD.

The Study

This was a prospective, single-center, open-label, parallel-arm pilot randomized controlled trial conducted at a hospital in Brisbane, Australia.

Population

The investigators enrolled adult patients who had been on peritoneal dialysis for at least three months. A key inclusion criterion was that patients had to be currently taking the osmotic laxative Movicol, which is the brand name for macrogol, as prescribed by their treating team. Patients were excluded if they had a history of major bowel surgery, active inflammatory bowel disease, or any condition that would interfere with study participation.

Intervention and Comparator

Twenty patients were randomized in a one-to-one ratio. The intervention group, with eleven patients, was instructed to stop taking Movicol and instead start taking psyllium husk. The initial dose was one 8-gram scoop per day, which could be titrated up to three scoops daily based on bowel motion frequency and stool consistency. The control group, with nine patients, was instructed to continue their usual Movicol regimen. The study duration was four weeks.

Outcomes

Because this was a feasibility trial, the primary outcome was recruitment feasibility. The investigators set a target of successfully recruiting 60 patients, which they estimated would represent about 70 percent of the eligible PD patients at their center.

Secondary outcomes were key to understanding the potential of the intervention. These included adherence, defined as taking more than 80 percent of the prescribed therapy; retention, meaning the proportion of patients who completed the full 28-day study; and safety, which included monitoring for adverse events like hyperkalemia. The researchers also collected patient-reported outcomes using validated questionnaires to assess gastrointestinal symptom burden and quality of life, and they tracked clinical outcomes like bowel motion frequency.

Key Findings

First, let's look at the primary outcome of feasibility. The study did not meet its original recruitment target of 60 patients. The researchers only enrolled 20. However, the reason for this is the most telling finding of the trial.

Recruitment

The team screened 96 patients. Of these, 66 were deemed ineligible. The main reason for ineligibility, accounting for 41 of those 66 patients, was non-adherence to their prescribed Movicol. In other words, nearly two-thirds of the ineligible patients were not taking the standard-of-care laxative they were supposed to be on. This is a significant finding in itself about real-world adherence.

Of the 30 patients who *were* eligible, 20 consented to participate. This represents a recruitment rate of 67 percent of the eligible population, which is very close to their pre-specified target of 70 percent. So, while the absolute number was low, the willingness to participate among eligible patients was high.

Adherence and Retention

In the psyllium husk group, adherence and retention were strong. Seventy-eight percent of participants took more than 80 percent of their prescribed psyllium dose. The two participants who didn't meet this threshold were taking a lower dose because it was already effective for them. All participants in the control group reported full adherence to their Movicol. Retention was also excellent; aside from two patients in the psyllium group who withdrew because they received kidney transplants, all other participants in both groups completed the four-week study.

Patient-Reported Outcomes

This is where psyllium husk showed a clear signal of benefit. Using the Edmonton Symptom Assessment scale, which measures symptom distress, patients in the psyllium group reported a significant improvement in their quality of life. Their median global distress score dropped dramatically from 14 at baseline to 4 at the end of the study. In contrast, the score in the Movicol group remained stable, going from 6 to 7. This difference between the groups over time was statistically significant, with a p-value of 0.008. A similar significant benefit was seen for the physical distress component of that scale.

Scores on the Gastrointestinal Symptom Rating Scale also trended downwards in the psyllium group, indicating fewer GI symptoms, while they remained stable in the Movicol group, though this difference did not reach statistical significance.

Clinical Outcomes and Safety

Interestingly, there were no major differences in bowel frequency or Bristol Stool Score between the groups. Bowel frequency actually decreased slightly in the psyllium group. The authors speculate this may be because many in that group already had optimal stool consistency at baseline, and the psyllium helped to moderate their bowel frequency without making stools harder to pass.

Most importantly, the intervention was safe. There were no serious adverse events reported in either group. There were no documented episodes of hyperkalemia, volume overload requiring hospitalization, or catheter malfunctions.

Strengths and Limitations

This study has several strengths. It was a randomized trial, which is the gold standard, and it addressed a very common and patient-important clinical problem. As a pilot study, it was well-designed to provide crucial data on feasibility, adherence, and safety, which is exactly what’s needed to plan a larger, more definitive trial.

Limitations

However, the limitations are also important to consider. The most significant is the small sample size. With only 20 patients from a single center, the study was not powered to definitively assess clinical efficacy, and the results may not be generalizable to other PD populations. The open-label design is another key limitation; since both patients and investigators knew the treatment allocation, this could have introduced bias, particularly in the patient-reported outcomes. The four-week follow-up period is also quite short, so we can't draw conclusions about long-term adherence or effectiveness. Finally, the high rate of ineligibility means the study’s findings technically only apply to the select group of PD patients who are already adherent to a prescribed laxative, which, as the study itself showed, may be a minority.

Clinical Bottom Line

So, what does this mean for clinical practice?

The first major takeaway is a reality check on standard care. The fact that two-thirds of potentially eligible patients were excluded because they weren't taking their prescribed laxative is a powerful reminder to clinicians. Before escalating treatment for constipation, it's crucial to have an open conversation with patients about their actual adherence to the current regimen.

Second, for PD patients who are struggling with constipation or who dislike their current laxative, psyllium husk appears to be a safe, well-tolerated, and promising alternative. In this small trial, it significantly improved symptom burden and quality of life compared to standard care with macrogol. Given its low cost and excellent safety profile, considering a trial of psyllium husk in these patients is a very reasonable clinical step.

However, it's important to frame this as a promising pilot study, not a definitive practice-changing one. It provides a strong rationale and the necessary groundwork for a larger, multi-center randomized controlled trial. Such a trial would be needed to confirm these benefits and to evaluate the impact of psyllium on hard clinical outcomes that matter most in PD, such as catheter dysfunction, peritonitis rates, and technique survival.

That's your AudioScholar summary. The full transcript and reference are on the episode page. This is an AI-generated summary — for clinical decisions, always consult the primary source. Until next time.