From the databaseWhat the row says.
Every entry follows the same shape: what is happening, the mechanism, and the recommendation.
Pair type
Timing Sensitive
Scope
Supplement × Supplement
Last verified
June 4, 2026
Timing SensitiveEmerging evidence
What is happening. Fiber and oligosaccharides may reduce predictable iron supplement absorption when taken together.
Mechanism. Altered transit and fiber matrix can reduce immediate mineral absorption reliability.
Recommendation. Separate iron supplements from GOS by at least 2 hours when correcting deficiency.
TimingTiming & separation.
Space the doses apart by at least this window to avoid the conflict.
Stack Score
How it moves the number.
Effect on the composite score
If both Galactooligosaccharides (GOS) and Iron are in the same stack, this pair applies −5 to your Stack Score (per scored timing-sensitive row).
The full algorithm, the clamping rules, and four worked stacks are at /methodology/stack-score.
SourcesSources, by evidence tier.
Every claim on this page is cited. PMIDs link straight to PubMed.
Reference material
1- 1Staudacher HM et al. B-GOS and low-FODMAP diet. Gastroenterology. 2020.Needs sourceNo link