Symptomatic response to varying levels of fructo-oligosaccharides consumed occasionally or regularly

To evaluate in 14 healthy volunteers the gastrointestinal tolerance to an indigestible bulking sweetener containing fructo-oligosaccharides (FOS).

In order to mimic their usual pattern of consumption, FOS were ingested throughout the day either occasionally (once a week, first period) or regularly (every day, second period). In the two patterns of consumption, daily sugar doses were increased until diarrhoea and/or a symptom graded 3 (i.e. severe) occurred, or when subjects did not want to ingest more candies.

Clinical Nutrition Unit, Hôpital Saint-Lazare, Paris.

In both periods, the first symptom which occurred was excessive flatus (> 30 g FOS/day): borborygmi and bloating appeared at a higher level (> 40 g/day); lastly, abdominal cramps and diarrhoea occurred at a very much higher level (50 g/day). The volumes of hydrogen excreted in breath in response to the same load of FOS were not different between the two periods.

Chronic consumption of FOS initiated cautiously with subsequent gradual increase did not improve tolerance, nor reduce breath excretion of hydrogen.