A study of fructo oligosaccharides in the prevention of travellers' diarrhoea

Background: Prebiotic carbohydrates selectively stimulate the growth of bifidobacteria and lactobacilli in the human colon. These bacteria form part of the gut's inherent defence against invading pathogens. Aim: To test the effectiveness of fructo oligosaccharides in preventing travellers' diarrhoea. Methods: A total of 244 healthy subjects, travelling to high and medium risk destinations for travellers' diarrhoea, took part in a randomized, double-blind, placebo-controlled study. The protocol comprised a preliminary week for recording bowel habit by diary, a 2-week pre-holiday period with the diary and consumption of 10 g of fructo oligosaccharides or placebo daily, followed by a 2-week holiday with continuation of treatment and diary. A post-study questionnaire was completed by all subjects on their return to the UK. Results: The consumption of fructo oligosaccharides led to a small (6%; P < 0.02) increase in stool frequency in the pre-holiday period and gave a significantly better sense of 'well-being' during the holiday, although subjects reported more flatulence. There were non-significant decreases in episodes of diarrhoea with 20% on placebo and 11% on fructo oligosaccharides recording episodes in the post-study questionnaire (P=0.08) and 46% placebo, 38% fructo oligosaccharides recording episodes in the diary (P > 0.1). No change in bowel frequency, consistency or stool size was recorded. Conclusion: Travel to high risk areas increases diarrhoea. Fructo oligosaccharides alone are not sufficient to prevent this, although do have some benefits for the subjects.