An enzyme cut the bloating from a big inulin dose without changing a single breath gas

Each participant ate 25 g of inulin stirred into 40 g of oatmeal on two occasions, once with a fructanase capsule and once with a maltodextrin placebo, rating symptoms for 24 hours and giving breath samples hourly for 8 hours.

The headline 0 to 8 hour overall abdominal symptom score did not separate the two conditions (p=0.13). Within that window, abdominal pain (p=0.044), fatigue (p<0.001) and burping (p=0.040) did.

The clearer separation came later. Across 8 to 24 hours the overall abdominal symptom score favoured the enzyme (p=0.030), along with bloating (p=0.011), abdominal pain (p=0.019) and flatulence (p=0.044).

Breath hydrogen and methane showed no significant difference between conditions at any point, which is the measurement the mechanism depends on.

The numbers

Overall abdominal symptoms, 0 to 8 h	no difference, p=0.13
Overall abdominal symptoms, 8 to 24 h	favoured enzyme, p=0.030
Bloating, 8 to 24 h	p=0.011
Flatulence, 8 to 24 h	p=0.044
Breath hydrogen and methane	no significant difference

Why this might happen

Open question The authors do not claim to know why.

The stated premise is straightforward. Fructanase hydrolyses fructans to fructose in a test tube, so taking it with inulin should mean less fructan arriving in the colon and less fermentation.

The study's own data undercut that account. Breath hydrogen and methane are the standard non invasive readout of colonic fermentation, and neither differed between conditions.

So the symptom benefit, such as it is, is not explained by reduced fermentation on the evidence presented here.

The discussion is not openly reachable, so whatever alternative the authors propose is not something we can report.

Drawn from Abstract and the study's own breath gas data, full text behind a publisher block.

What this does not show

It does not show that the enzyme worked the way the authors expected. The premise is that fructanase breaks fructans down before they reach the colon, so less is fermented. Breath hydrogen and methane, the standard readout of colonic fermentation, did not move. Something reduced the symptoms, and the study does not establish what.
The primary window was null. The 0 to 8 hour overall abdominal symptom score came out at p=0.13. Everything positive is either a secondary symptom domain or the later window, and the abstract shows no correction for multiplicity.
It does not show anything about people with IBS. Thirty healthy adults with a mean age of 38.6 years. The population that actually reacts to fructans was not studied, and the authors name that as the trial still needed.
The independence of the work is limited. The author list is drawn from the enzyme developer and a contract research organisation, including the corresponding author. That does not make the result wrong, but it is not an independent test.

Where this leaves us

There is now a symptom signal for a fructan digesting enzyme, and simultaneously a reason to doubt the mechanism everyone assumed it worked by. The finding and its explanation moved in opposite directions.

Thirty healthy adults in their late thirties given a single large inulin load, not people with IBS or diagnosed fructan intolerance.

The authors name it themselves: the same trial in people with IBS or fructan intolerance, ideally run by a group with no commercial interest in the enzyme, with a primary endpoint chosen in advance.

Caveats worth holding

The abstract reports p values without effect sizes, so the size of the symptom benefit is unconfirmed here.
PubMed records the online date as 11 August and Crossref records 12 August. The earlier date is cited.
Industry authorship from the enzyme developer and a contract research organisation.
Volume and issue are not yet assigned.