Oligofructose contributes to the protective role of bifidobacteria in experimental necrotising enterocolitis in quails

Bifidobacteria are dominant in the gut of full-term infants, although colon isation by them is often delayed in preterm neonates, Bifidobacteria are re cognised to have beneficial effects on digestive disorders and they might p revent neonatal necrotising enterocolitis (NEC), a gastrointestinal disease that predominantly affects premature infants. They have been shown to prot ect gnotobiotic quails against NEC-like lesions when the birds were inocula ted with faecal flora from preterm infants, decreasing the clostridial popu lation. The present study was designed to investigate whether oligofructose , which stimulates the activity of bifidobacteria, may enhance their protec tive role. Experiments were done in eight groups of germ-free quails for 28 days. The groups differed as to their bacterial status, diet and environme nt. Quails were inoculated with one of two flora from premature twins, The first flora included Bifidobacterium pseudo-catenulatum, Escherichia cell a nd no clostridia, The second flora included clostridial species and was ass ociated with B, infantis-longum. Caecal bacterial population and metabolism changes were investigated with a lactose (6%) diet versus a lactose-oligof ructose (3%-3%) diet, either in a gnotobiotic environment or in an ordinary environment permitting post-colonisation by exogenous bacteria. In both en vironments and with both flora, oligofructose significantly increased the l evel of bifidobacteria and this was associated with a decrease of E. coli o r C. perfringens and C, ramosum. The bacterial changes in the ordinary envi ronment depended on the initial composition of the microflora and the colon isation resistance against exogenous bacteria was more efficient with the f lora that included B, pseudo-catenulatum. The changes in caecal pH and shor t-chain fatty acids were minimal. It was demonstrated that, irrespective of the environmental conditions, the use of oligofructose helped to prevent t he overgrowth of bacteria implicated in necrotising enterocolitis in preter m neonates.