Inulin prebiotic: is it all about bifidobacteria?

In this issue, Vandeputte et al 1 present a unique study exploring the effects of chicory-derived inulin on the human gut microbiota by combining Next Generation Sequencing and faecal metabolomics to gain new insights into the mechanisms of action underlying inulin's health-promoting effects. The study supports that inulin prebiotics stimulate growth of bifidobacteria while simultaneously driving a number of other modulations of the gut microbial ecosystem that may be associated with health-promoting effects. Consumption of inulin-type fructans (ITFs) has been associated with a number of health benefits, including normalisation of GI function, regulation of body weight gain and energy metabolism.2 Some of the suggested mechanisms of action include regulation of the immune system, modulation of GI peptides, production of short chain fatty acids (SCFAs) and modulation of triglyceride metabolism.2–4 Down in the intestine, ITFs have long been known for their prebiotic activity targeted towards the enhancement of the genus Bifidobacterium.5 The latter is a well-known inhabitant of the human gut and one of the first micro-organism to colonise the infant's intestine at birth. Bifidobacteria are believed to promote health by producing some antimicrobial substances protecting the host from opportunistic pathogens, in addition to large amounts of lactic acid, which contribute to maintain a low pH in the colon, thereby limiting pathogen growth. Yet, inulin's prebiotic effects on human's gut microbial ecology have so far mostly been assessed using culture-based …