Evaluation of digestive tolerance of a soluble corn fibre.

Background: To assess consumers' acceptance of a new fibre, it is essential to evaluate its digestive tolerance after ingestion. We aimed to determine the tolerance of increasing dosages of Promitor™ Soluble Gluco Fibre (SGF; Tate&Lyle, Hoffman Estates, IL, USA) up to 70 g fibre per day using a validated gastrointestinal composite score.

Methods: A composite score of gastrointestinal tolerance integrating gastrointestinal symptoms, stool frequency and consistency was applied. To statistically validate this composite score, the gastrointestinal tolerance of inulin (10 g versus 20 g containing, respectively, 9 g versus 18 g of fibre) was assessed in 18 healthy volunteers in a randomised double-blind placebo-controlled cross-over study. Second, in a double-blind placebo-controlled cross-over study with 20 healthy volunteers, the gastrointestinal tolerance of SGF in both acute and 'spread over the day' conditions of consumption was assessed.

Results: By contrast to 10 g, 20 g of inulin demonstrated a significant difference in composite score compared to placebo [P < 0.001, difference = 7.6; 95% confidence interval (CI) = 3.8-11.3]. These values were considered as reference during the second study. In acute conditions, 40 g of SGF fibre was the highest (threshold) dose tested that indicates the digestive tolerance criteria (difference from placebo on the composite score <7.6 and upper limit of the 95% CI <11.3); this is twice the amount tolerated for inulin. In 'spread over the day' conditions, 65 g of SGF fibre was the threshold dose (P < 0.001, difference = 6.5; 95% CI = 3.4-9.5).

Conclusions: The results of the present study demonstrate that 40 g of SGF fibre, when consumed as a single dose, and 65 g of SGF fibre, when consumed in multiple-doses, across the day are well-tolerated by healthy volunteers.