Effects of low doses of lactitol on faecal microflora, pH, short chain fatty acids and gastrointestinal symptomology.

Background: Lactitol (4-beta-D: -galactopyranosyl-D: -glucitol) is a sugar alcohol used as a sweetener. Previous studies have shown that it has a beneficial effect on intestinal microflora.

Aims Of The Study: To determine whether low doses of lactitol had beneficial effects without eliciting adverse gastrointestinal symptoms.

Methods: Faecal bacterial populations (total anaerobes, total aerobes, enterobacteria, bifidobacteria and lactobacilli), faecal pH and faecal short chain fatty acids (SCFA) were studied in a randomized longitudinal study of 75 non-adapted healthy adults before and after consumption of low doses of lactitol. Subjects consumed 25 g tablets of milk chocolate containing 10 g sweetener as sucrose:lactitol in ratios of 10:0, 5:5 or 0:10 daily for 7 d.

Results: No significant changes in faecal bacterial counts occurred in the 10:0 or 5:5 sucrose:lactitol groups. There were no significant changes in faecal anaerobes, aerobes, Enterobacteriaceae or lactobacilli during the study period in subjects consuming 0:10 sucrose:lactitol but there was a significant increase (P = 0.017) in bifidobacteria. There were no significant changes in faecal pH and SCFA for the 10:0 or 5:5 sucrose:lactitol groups but a significant decrease (P = 0.02) in faecal pH and significant increases (P = 0.001) in concentrations of propionic and butyric acids were observed in the 0:10 sucrose:lactitol group. There were few adverse symptoms of gastrointestinal intolerance to the daily consumption of 10 g lactitol.

Conclusions: The results show that low doses of lactitol can beneficially affect the faecal flora without eliciting gross symptoms of intolerance and that lactitol can be classified as a prebiotic.