Induction of artificial fat maldigestion by tetrahydrolipstatin assessed by the (13)C-hiolein breath test in healthy volunteers. A double-blind controlled pilot study.
BACKGROUND: (13)C-hiolein is a purified algal triglyceride which is synthesized with 98% of all carbon atoms of the molecule uniformly (13)C-labeled. Orlistat is the new name for tetrahydrolipstatin (THL), which is a specific and potent inhibitor of gastrointestinal lipases which induces artificial fat malabsorption in humans. The aim of the present study was to use the (13)C-hiolein breath test (HBT) to assess THL-induced fat malabsorption in healthy volunteers. METHODS: Eight healthy volunteers of normal body weight underwent 2 study periods of 4 days of diet with or without THL 120 mg t.i.d. On day 5, a HBT was performed. (13)CO(2) recovery in breath samples was measured over 24 h by isotope ratio mass spectrometry. RESULTS: The peak (13)CO(2) excretion occurred only after 5 h in both treatment groups with little difference during the first 4 h between the groups. THL potently reduced fat digestion and absorption with the most pronounced effect observed after 8 h: 1.1+/-0.2 vs. 2.3+/-0.3% dose in control experiments (p<0.05). The 24-hour cumulative (13)CO(2) excretion was also significantly reduced by THL: 14.9+/-2.2 vs. 28.4+/-4.1% dose in control experiments (p<0.05). In 6 of the 8 subjects, the cumulative (13)CO(2) excretion was lower with THL 120 mg t.i.d. than with placebo. CONCLUSION: The HBT well reflects THL-induced artificial fat maldigestion in healthy volunteers.