Effect of functional food ingredients on gut microbiota in a rodent diabetes model

BACKGROUND: The gut microbiota has been shown to be involved in the development and severity of type 2 diabetes. The aim of the present study was to test the effect of 4-week functional food ingredient feeding, alone or in combination, on the gut microbiota composition in diabetic rats. METHODS: Streptozotocin (STZ)-induced diabetic rats were treated for 4 weeks with (1) native taro starch, (2) modified taro-starch, (3) beet juice, (4) psicose, (5) the probiotic L. plantarum IS-10506, (6) native starch combined with beet juice, (7) native starch to which beet juice was adsorbed, (8) modified starch combined with beet juice or (9) modified starch to which beet juice was adsorbed, to modulate the composition of the gut microbiota. This composition was evaluated by sequencing the PCR amplified V3–V4 region of the 16S rRNA gene. RESULTS: The next-generation sequencing showed beneficial effects particularly of taro-starch feeding. Operational taxonomic units (OTUs) related to health (e.g. correlating with low BMI, OTUs producing butyrate) were increased in relative abundance, while OTUs generally correlated with disease (e.g. Proteobacteria) were decreased by feeding taro-starch. CONCLUSION: The results of study show that a 4-week intervention with functional food ingredients, particularly taro-derived starch, leads to a more healthy gut microbiota in rats that were induced to be diabetic by induction with STZ.