The effect of glutamine-enriched enteral nutrition on intestinal microflora in very low birth weight infants: a randomized controlled trial.

BACKGROUND & AIMS: In a previous study, we have found that glutamine supplementation decreased the infection rate in very low birth weight (VLBW) infants. In this study, we investigated whether this beneficial effect originated from increased number of bifidobacteria and lactobacilli in the intestinal microflora of these infants. METHODS: In a randomized controlled trial, VLBW infants (gestational age <32 weeks and/or birth weight <1500g) received enteral glutamine supplementation (0.3g/kg/day) or isonitrogenous placebo supplementation between d3 and d30 of life. Faecal microflora was determined by fluorescent in situ hybridization <48h, at d7, d14 and d30 of life. RESULTS: In 43/52 (glutamine group) and 43/50 (control group) infants, > or = 2 samples were analyzed. Baseline characteristics were not different between groups. The prevalence of bifidobacteria, lactobacilli, Escheria coIi, streptococci and clostridia was not different between groups (p>0.05). In both groups, colonization with bifidobacteria was delayed, whereas potentially pathogenic bacteria such as E. coli, appeared rapidly after birth. Antibiotic treatment decreased the prevalence of all faecal bacteria (p<0.05). CONCLUSIONS: Decreased infectious morbidity in VLBW infants that received glutamine supplementation was not associated with alterations in the prevalence of bifidobacteria, lactobacilli, E. coIi, streptococci and clostridia. In general, colonization with health-promoting bacteria was delayed, whereas potentially pathogenic bacteria appeared rapidly after birth. Antibiotic treatment delayed the bacterial colonization.

Effects of total enteral nutrition supplemented with a multi-fibre mix on faecal short-chain fatty acids and microbiota.

BACKGROUND AND AIMS: Impaired bowel function is frequent in tube-fed patients, and diarrhoea is associated with decreased faecal short-chain fatty acids (SCFAs) concentrations. The aim of this study was to compare the effects of a multi-fibre-enriched formula (15 g/l) and a fibre-free isoenergetic and isonitrogenous formula on faecal SCFAs and microbiota in long-term enteral nutrition (EN) patients. METHODS: Fifteen patients [11M/4F, aged 53 (40-73)] on total EN for 43 (1-310) months for dysphagia received a fibre-free formula for 7 days, followed in a random order by either the multi-fibre-enriched formula for 14 days and then the fibre-free formula for 14 days or vice versa. Stool samples were taken at the end of each period for measurement of SCFAs levels and different groups of bacteria. Results were compared with non-parametric tests. RESULTS: After the multi fibre EN, there was a significant median increase in total faecal SCFAs (+84%), butyrate (+20%) and acetate (+147%) compared with baseline. A significant increase in the total number of bacteria as determined with the molecular method was found after the multi-fibre EN period compared with the fibre-free EN period. There were no concomitant changes in the dominant groups of intestinal bacteria. CONCLUSION: In long-term EN patients, a polymeric enteral formula supplemented with a mixture of six fibres increases faecal SCFAs and total number of bacteria, which may contribute to an improved bowel function.

Bifidogenic effects of solid weaning foods with added prebiotic oligosaccharides: a randomised controlled clinical trial.

OBJECTIVES: Breast-fed infants have relatively high proportions of faecal bifidobacteria. This bifidogenic microbiota is at least partly explained by the high levels of prebiotic oligosaccharides in human milk. The present study aimed at testing the effect of solid foods with added prebiotic galacto- and fructo-oligosaccharides (GOS/FOS) on the composition of the intestinal microbiota of fully formula-fed infants during the weaning period. METHODS: The study was a double-blind, randomised trial with an intervention period of 6 weeks. Infants aged 4 to 6 months who were about to start consuming solid foods were randomised to receive either weaning products with a mixture of GOS/FOS or control weaning products with maltodextrin. After an adjustment period, the presented daily dose of GOS/FOS was 4.5 g. Total numbers of bacteria and bifidobacteria in faecal samples were analysed with fluorescent in situ hybridization. RESULTS: Thirty-five infants were included in the study, and 20 infants were included in a per-protocol analysis. In the GOS/FOS group, the faecal percentage of bifidobacteria significantly increased from 43% to 57% (P = 0.031) from week 0 to week 6, but did not significantly change in the control group (36% and 32%, respectively; P = 0.387). The change in the percentage of bifidobacteria between week 0 and week 6 in the GOS/FOS was significantly different from this change in the control group (P = 0.026). CONCLUSIONS: We conclude that addition of GOS/FOS to solid foods induces an increase in the faecal proportion of bifidobacteria in the intestinal microbiota of fully formula-fed infants with an established, mixed-type microbiota in the weaning period.