# Abstract

**Background:** Fructanase, an enzyme that hydrolyzes dietary fructans to fructose in vitro, may reduce gastrointestinal (GI) microbial fermentation in vivo by breaking down fructans before transit to the colon.

**Objective:** This study evaluated the effects of a microbial fructanase on GI symptoms and intestinal fermentation in men and women after inulin-type fructan ingestion.

**Methods:** A randomized, double-blind crossover study design was used with 30 healthy adults \[mean (standard deviation) age 38.6 (7.3) y and BMI 24.5 (3.0) kg/m^(2)\] who consumed 25 g inulin mixed into 40 g oatmeal with either one capsule containing fructanase or placebo maltodextrin. GI symptoms and fatigue were assessed using visual analog scales at baseline and postprandially for 24 h. Breath hydrogen and methane concentrations were measured postprandially hourly for 8 h. A Wilcoxon signed-rank test was used to compare paired differences between fructanase and placebo conditions.

**Results:** The maximum 0-8 h overall abdominal symptom score was not statistically significant (P = 0.13) between groups. Compared to placebo, fructanase co-administration with inulin reduced abdominal pain (P = 0.044) and fatigue (P < 0.001). Rank-based repeated measures analysis showed that fructanase reduced burping (P = 0.040) in the 0-8 h period. Over the 8-24 h period, fructanase reduced overall abdominal symptoms (P = 0.030), bloating (P = 0.011), abdominal pain (P = 0.019), and flatulence (P = 0.044). Breath hydrogen and methane outcomes did not differ significantly between groups.

**Conclusions:** Fructanase co-administration with inulin reduced GI symptoms in healthy adults, suggesting that it may be a useful dietary supplement for fructan sensitivity. Further trials in a cohort with GI symptoms such as irritable bowel syndrome are warranted. Registered at [ClinicalTrials.gov](http://ClinicalTrials.gov) ([NCT06628869](http://clinicaltrials.gov/show/NCT06628869)). Clinical Trial Registry number and website where it was obtained Registered at [ClinicalTrials.gov](http://ClinicalTrials.gov) ([NCT06628869](http://clinicaltrials.gov/show/NCT06628869)) on October 3, 2024. Link: https://clinicaltrials.gov/study/NCT06628869.

Oral Fructanase Administration Reduces Gastrointestinal Symptom Severity After Acute Inulin Challenge in Healthy Adults