Human gut microbiota fermentation of microbial-fructooligosaccharides

Abstract

Introduction: Prebiotics have been shown to significantly impact gut microbiota composition, viability and metabolic activity. The prebiotic potential of microbial-fructo-oligosaccharides (microbial-FOS) produced by a newly isolated strain of Aspergillus ibericus in co-culture with a Saccharomyces cerevisiae YIL162W was herein evaluated.

Methods: Microbial-FOS were in vitro fermented by human faeces of five healthy volunteers in anaerobic batch cultures for 24 h. Fermentations were also run with a non-microbial commercial FOS sample Raftilose® P95. During fermentation, the dynamic bacterial population changes were assessed by quantitative real-time PCR (qPCR), and the production of short chain fatty acids (SCFA) and sugar consumption by HPLC. Microbial-FOS chemical structure was characterized by gas chromatography quadrupole mass spectrometry (GC-qMS).

Results and Discussion: Microbial-FOS significantly stimulated the growth of Bifidobacteria probiotic strains, triggering a beneficial effect on gut microbiota composition. A great amount of total SCFA was produced by microbial-FOS fermentation as compared to the commercial-FOS, particularly propionate and butyrate. Inulin neoseries oligosaccharides (e.g., neokestose) were only identified in the microbial-FOS sample, which may explain their different functionalities.

Conclusion: FOS produced by A. ibericus exhibit promising potential as nutraceutical ingredients for gut microbiota modulation.