The impact of dietary fibres on gut microbiome of young children: insights from in vitro experiments and an observational cohort

During weaning period, the intake of dietary fibres changes and increases dramatically. Given the considerable structural differences, we hypothesized that different fibres may vary in their function. The objective of the study was to explore the impact of specific dietary fibres (arabinoxylan, cellulose, pectin and xyloglucan) on the gut microbiome of children below 3 years. By using in vitro fecal fermentation experiments, cellular models and cohort data analysis, we assessed how these fibres and their combinations influence infants’ gut microbiota composition, diversity, metabolite production and possible actions on the gut epithelial barrier function. We found that the fermentation with arabinoxylan, xyloglucan and pectin resulted in an increased production of short-chain fatty acids. These fibres also promoted the generation of metabolites with potential health benefits, such as indole-3-lactic acid. By combining the in vitro fermentation and cellular co-culture experiments, arabinoxylan and xyloglucan were found to maintain gut epithelial barrier integrity upon lipopolysaccharide (LPS) challenge, and a blend of cellulose, pectin, and xyloglucan dampened different LPS induced cytokines. Moreover, pectin was found to supportthe growth of a wide range of microbial species in vitro and correlated positively with α-diversity in young children in an observational cohort. Our findings provide insights into the potential benefits of diverse fibre intakes during early life. Further studies are needed to investigate the causal relationship, mechanisms and the effectiveness of specific fibres on the gut microbiome development in young children.