In vitro fermentation of fructooligosaccharide and galactooligosaccharide and their effects on gut microbiota and SCFAs in infants

Abstract

Oligosaccharides are widely added to infant formula milk powders as prebiotics for intestinal health. Using in vitro fermentation conditions, this study investigated the fermentation characteristics of fructooligosaccharides (FOS) and galactooligosaccharides (GOS) with infant fecal inoculum. The changes in short-chain fatty acids (SCFAs) and lactate production were monitored by HPLC. The contents of SCFAs and lactate increased significantly in the GOS and FOS + GOS groups. Furthermore, the metagenomic analysis revealed that microbial communities were distinctively different. Most bacteria were significantly positively correlated with SCFAs production and negatively correlated with pH, particularly Bifidobacterium, Enterococcus, Weissella and Streptococcus. More importantly, the relative abundance of most carbohydrate-active enzymes (CAZymes, EC:2.3.1.54, EC:2.3.1.9 and EC:2.8.3.8, etc.) were significantly higher in the GOS and FOS + GOS groups. These results suggested that FOS and GOS had a significant regulatory effect on the composition and metabolism of the intestinal microbiota, further promoting the production of SCFAs and lactate.

Keywords

• Metagenome
• Short-chain fatty acid
• Gut microbiota
• Fructooligosaccharides
• Galactooligosaccharides
• In vitro fermentation