Pathology

Placebo

Firmicutes

Inulin

Lactobacillus

Bifidobacterium

16S ribosomal RNA

Physiology

Bacteria

Gut flora

Biology

Fermentation

Prebiotic

Immunology

Alternative medicine

Sucrose

Lachnospiraceae

Ruminococcus

Fructan

Food science

Genetics

Medicine

British Journal Of Nutrition

Dysbiotic gut microbiota have been implicated in human disease. Diet-based therapeutic strategies have been used to manipulate the gut microbiota towards a more favourable profile. However, it has been demonstrated that large inter-individual variability exists in gut microbiota response to a dietary intervention. The primary objective of this study was to investigate whether habitually low dietary fibre (LDF) v . high dietary fibre (HDF) intakes influence gut microbiota response to an inulin-type fructan prebiotic. In this randomised, double-blind, placebo-controlled, cross-over study, thirty-four healthy participants were classified as LDF or HDF consumers. Gut microbiota composition (16S rRNA bacterial gene sequencing) and SCFA concentrations were assessed following 3 weeks of daily prebiotic supplementation (Orafti ® Synergy 1; 16 g/d) or placebo (Glucidex ® 29 Premium; 16 g/d), as well as after 3 weeks of the alternative intervention, following a 3-week washout period. In the LDF group, the prebiotic intervention led to an increase in Bifidobacterium ( P =0·001). In the HDF group, the prebiotic intervention led to an increase in Bifidobacterium ( P &lt;0·001) and Faecalibacterium ( P =0·010) and decreases in Coprococcus ( P =0·010) , Dorea ( P =0·043) and Ruminococcus (Lachnospiraceae family) ( P =0·032). This study demonstrates that those with HDF intakes have a greater gut microbiota response and are therefore more likely to benefit from an inulin-type fructan prebiotic than those with LDF intakes. Future studies aiming to modulate the gut microbiota and improve host health, using an inulin-type fructan prebiotic, should take habitual dietary fibre intake into account.

Habitual dietary fibre intake influences gut microbiota response to an inulin-type fructan prebiotic: a randomised, double-blind, placebo-controlled, cross-over, human intervention study