Supplementation of milk formula with galacto-oligosaccharides improves intestinal micro-flora and fermentation in term infants

Background Oligosaccharides in human milk may protect infants by improving the intestinal micro-flora and fermentation. This study was to investigate effects of infant formula milk consisting of galacto-oligosaccharide (GOS) on intestinal microbial populations and the fermentation characteristics in term infants in comparison with that of human milk. Methods The test formula (Frisolac H,Friesland,Netherland) was supplemented with GOS at a concentration of 0.24 g/dl. Human milk and another formula without oligosaccharides (Frisolac H,Friesland,Netherland) were used as positive and negative control respectively. Growth,stool characteristics,and side effects of the recruited infants were recorded after 3 and 6 months’ follow-up,and the fecal species were collected for the analysis of intestinal micro-flora,short chain fatty acid (SCFA) and pH.Results At the end of 3- and 6-month feeding period,intestinal Bifidobacteria and Lactobacilli were significantly increased in infants fed with GOS supplemented formula and human milk when compared with infants fed with negative control formula; however,there was no statistically significant difference between GOS supplemented formula and human milk groups. Stool characteristics were influenced by the supplement and main fecal SCFA (acetic),and stool frequency were significantly increased in infants fed with GOS supplemented formula and human milk,while the fecal pH was significantly decreased as compared with that of negative control ( P <0.05). Supplementation had no influence on incidence of side effects (including crying,regurgitation and vomiting). Conclusions Supplementing infant formula with GOS at a concentration of 0.24 g/dl stimulates the growth of Bifidobacteria and Lactobacilli in the intestine and stool characteristics are similar to in term infants fed with human milk.

Duplication and functional diversification of pancreatic ribonuclease (RNASE1) gene

Adaptation is one of the most fundamental issues in the studies of organismal evolution. Pancreatic ribonuclease is a very impor- tant digestive enzyme and secreted by the pancreas. Numerous studies have suggested that RNASE1 gene duplication is closely related to the functional adaptation of the digestive system in the intestinal fermentation herbivores. RNASE1 gene thus becomes one of the most important candidate genetic markers to study the molecular mechanism of adaptation of organisms to the feeding habit. Interestingly, RNASE1 gene duplication has also been found in some non-intestinal fermentation mammals, suggesting that RNASE1 gene may have produced novel tissue specificity or functions in these species. In this review, RNASE1 gene and its im- plications in adaptive evolution, especially in association with the feeding habit of organisms, are summarized.