ABSTRACTS: Oral Presentation Abstracts
Introduction: The bacterial composition of the colonic micro-flora is reflected in the pattern of faecal short chain fatty acids (SCFAs). Breastfed infants have relatively high levels of acetate and lactate in faeces, while in formula fed infants levels of propionate and butyrate are higher than in breastfed infants. Since propionate and butyrate are produced by other strains than bifidobacteria, it can be hypothesized that changes in levels of faecal bifidobacteria will be reflected in the levels of faecal SCFAs. In a previous publication we have shown that weaning foods with added galacto- and fructooligosaccharides (GOS/FOS) significantly increase the percentage of faecal bifidobacteria in fully formula fed infants. The aim of the current study was to identify the changes in faecal levels of SCFAs of fully formula fed infants that are introduced to solid foods with added GOS/FOS.
Methods: The study was a double-blind, randomized trial with a six-week intervention period. Fully formula fed infants were randomized to receive either weaning foods with a mixture of GOS/FOS or with Maltodextrin (MALT). The presented daily dose of GOS/FOS was 4,5 g. Levels of SCFAs were analyzed before the introduction of solids (t=0) and six weeks thereafter (t=6). Differences between the groups were analyzed with the Mann-Whitney U test, after correction for baseline values.
Results: Thirty-five infants were included in the study. For twelve infants, the amount of faeces was not enough for the analysis of SCFAs. The mean age at study-entrance was 125 days (±17 days). The median percentages of SCFAs are summarized below. There was a trend towards a higher percentage of acetate (p=0.091) and a lower percentage of propionate (p=0.190) in the GOS/FOS group, compared to the MALT group in the sixth week of intervention. For butyrate, a significant difference between the two groups was observed (p=0.009).
Conclusion: The present results demonstrate that the addition of GOS/FOS to solid foods affects the metabolic activity of the intestinal microflora, reflected in higher percentages of faecal acetate and lower percentages of faecal propionate and butyrate. Hence, the addition of GOS/FOS to solid weaning foods not only affects the percentage of bifidobacteria, but also the metabolic activity in faeces of fully formula fed infants in the weaning period.