Alpha-Galactosidase and IBS

What 3 graded rows on alpha-galactosidase agree on for IBS, and where they differ. Counted side by side, never averaged.

Consensus finder Rows from the Alpha-Galactosidase page, reviewed Oct 21, 2026 How it decides

What the rows agree on

Each block and row is one graded row from the Alpha-Galactosidase page, with its PubMed record.

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Alpha-Galactosidase and IBS

3 rows · 176 people

Mostly no difference: 2 of 3 rows, and most of the people. 1 found an improvement.

No difference

Improved

Each block is one evidence row, sized by how many people it enrolled, with its grade inside.

Grade D× 1
No effect× 2

Rows: 3
Trials: 3
People: 176

Where they differ

From the rows

Trial sizeWho was studied

The best-graded row, grade D, is a crossover trial of 31 people (2018) and found an improvement. 2 rows are graded No effect, our grade for adequately powered trials that found no effect.

The 2 rows that found no difference were larger: a median of 73 people, against 31 people for the row that found an improvement.

Only the 2 rows that found no difference name women in their population.

The rows

1 improved · 2 no difference

No effectIBS symptom severity and quality of life · No difference
RCT · n 125 · 2016 · 125 people with IBS and bloating or flatulence
With meals (amount not stated in the abstract) · 12 weeks plus 4-week follow-up
Only a trend toward lower IBS symptom scores, and quality of life did not differ. More people withdrew on the enzyme (18 vs 7, p = 0.016), more often citing abdominal pain and diarrhoea.
Row on the Alpha-Galactosidase page · PubMed 26133538 (opens PubMed)
No effectAfter-meal symptoms in IBS · No difference
Crossover RCT · n 20 · 2021 · 20 adults with IBS (19 women)
1,200 GalU per meal with three high-oligosaccharide meals (vs placebo) · Single test days
Symptom ratings, breath hydrogen and methane did not differ between enzyme and placebo days.
Row on the Alpha-Galactosidase page · PubMed 33619835 (opens PubMed)
Grade DSymptoms from high-GOS foods in IBS · Improved
Crossover RCT · n 31 · 2018 · 31 hydrogen-producing IBS patients; 21 were GOS-sensitive
300 GALU (full dose) or 150 GALU with high-GOS meals (placebo: glucose) · 3-day high-GOS diet per arm
In GOS-sensitive patients, the full dose reduced overall symptoms (median 24.5 vs 5.5 mm on a 100 mm scale, p = 0.006) and bloating (20.5 vs 6.5 mm, p = 0.017); breath hydrogen did not differ.
Row on the Alpha-Galactosidase page · PubMed 28809383 (opens PubMed)

Read onRead the full evidenceThe full evidence chapter on its page, with every outcome and its sources.