Effect of Fructooligosaccharide Containing Enteral Formulas on Subjective Tolerance Factors, Serum Chemistry Profiles, and Faecal Bifidobacteria in Healthy Adult Male Subjects

Abstract

Fructooligosaccharides (FOS) are an ingredient which may be incorporated into enteral products. However, prior to the addition of FOS to such products, studies related to the identification of any negative side effects associated with their consumption must be conducted. This double-blind study was conducted to assess the effect of FOS-containing enteral formulas on subjective tolerance factors, serum chemistry profiles and faecal bifidobacteria in healthy male college students. Three dietary formulas were investigated including a low residue polymeric formula (A), A+5 g FOS/L (B), and A+10 g FOS/L (C). Twenty-seven students (nine subjects/treatment) were randomly assigned to one of the dietary treatments. Subjects consumed the specified formula as their sole source of nutrition for 14 d. The amount of formula consumed by each subject was recorded daily and caloric intakes were adjusted to maintain the subjects' initial body weight. Faecal and blood samples were collected at baseline (day 0) and day 14. Using a daily questionnaire, subjects were asked to report the frequency of the following gastrointestinal symptoms: nausea, cramping, diarrhoea, distention, flatus, vomiting and regurgitation. Daily consumptions of FOS (g ± SEM) were 0 ± 0, 15 ± 1·0, and 31 ± 2·6 for dietary treatments A, B, and C, respectively. Tolerance to all dietary treatments was good. Few complaints of nausea, cramping, diarrhoea, marked distention, vomiting or regurgitation were reported regardless of treatment. More complaints of flatus and slight distention were reported with the FOS-containing diets, particularly diet C, compared with A. These symptoms were mild and subsided as the study progressed. No clinically significant differences in serum chemistries were detected as a function of formula intake. Faecal microbiota changes, as a function of diet, were detected. Specifically, the ingestion of diets B and C resulted in greater (P<0·001) bifidobacteria levels in faeces compared with A on day 14. Results indicate that fructooligosaccharides do not compromise serum chemistries, are well tolerated particularly at an intake of 15 g/d, and are a bifidogenic factor in low residue polymeric formulas.