Dietary fibre supplementation to reduce side effects of prostate radiotherapy (DIETRICH study)

Phase 2 randomised controlled trial of effects of the dietary fibre supplement inulin versus placebo on intestinal and urinary side effects in men receiving standard of care radiotherapy for intermediate/high risk localised or locally advanced prostate cancer

Status

Active, not recruiting

Phases

Unknown

Study type

Interventional

Source

ISRCTN

Registry ID

ISRCTN87108662

Enrollment

220

Registered

2026-01-06

Start date

2026-06-01

Completion date

Unknown

Last updated

2026-04-27

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Prevention of acute bowel toxicity and urinary side effects in men undergoing radiotherapy for prostate cancer. Cancer

Interventions

We will aim to recruit 220 men who have opted for radiotherapy treatment for their prostate cancer. Half the men who take part in DIETRICH will be given a supply of inulin to take for 2 weeks before r

8g in the morning and 8g in the evening. The inulin/maltodextrin (placebo) which will be in powdered form and can be added to cold drinks and taken orally. Participants will not know what treatment t

Eligibility

Sex/Gender

Male

Age

18 Years to 100 Years

Inclusion criteria

Inclusion criteria: 1. Men with intermediate/high risk localised or locally advanced prostate cancer planned to receive radical radiotherapy to the prostate with or without pelvic nodes. 2. Have Cambridge Prognostic Group (CPG) 3, 4 or 5 prostate cancer 3. T1-3 N0 M0 4. Receiving radical radiotherapy to the prostate with or without pelvic nodes (60 Gy in 20 fractions over 4 weeks) 5. Age =18 years 6. Are able and willing to give informed consent to participate and to participate in study procedures 7. Have a WHO performance status 0-2 (well enough to perform daily activities with only mild restrictions identified at screening/first visit).

Exclusion criteria

Exclusion criteria: 1. T4 disease 2. History of colectomy, stoma (ileostomy or colostomy), or other major gastrointestinal surgeries altering bowel anatomy 3. Prior radiotherapy to the prostate or pelvis 4. Prior radical prostatectomy 5. Prior androgen deprivation therapy (ADT) for >12 months at randomisation 6. Patient to have rectal spacer inserted for radiotherapy 7. Poorly controlled diabetes mellitus (Patient reported) 8. Coeliac disease 9. Known allergy to maltodextrin (placebo) 10. Known allergy to inulin 11. Life expectancy <5 years 12. Men without capacity

Design outcomes

Secondary

Measure	Time frame
Tertiary outcome measures Hormonal and sexual function measured by EPIC-26 at week –2, week 0, week 4, week 6, week 10 and week 16.	—

Countries

England, Scotland, United Kingdom

Contacts

Public ContactKirsteen Goodman

dietrich@abdn.ac.uk+44 1224 438103

Outcome results

None listed

Source: ISRCTN (via WHO ICTRP) · Data processed: May 1, 2026