In vitro fermentability of a broad range of natural ingredients by fecal microbiota from lean and obese individuals: potential health benefits

Abstract

The prevalence of obesity and related complications is continuously increasing while the gut microbiota might have a significant role to address this challenge. In this context, the food industry generates large amounts of residues that could be likely revalorised as functional ingredients. Hence, we evaluated the fermentability of food skins, husks, shells, trimming residues, mosses and mushrooms, which were subjected to in vitro fermentation with faecal microbiota from lean and obese adults. We demonstrated for the first time that pumpkin skin is highly fermented by human faecal microbiota showing pH-lowering effects and promoting gas and SCFA production. Furthermore, brewers’ spent grain generated an inulin-like SCFA profile after microbial fermentation, whereas Irish moss, plum skin, quinoa husk and mushrooms, including Armillaria mellea and Boletus edulis, showed high fermentation rates. Remarkably, although propionate production was significantly higher in obese individuals, the fermentability of the ingredients was similar between lean and obese conditions.

Keywords:

• Natural ingredients
• food by-products
• human faecal microbiota
• obesity
• in vitro fermentation

Acknowledgements

We gratefully acknowledge the collaboration of the volunteers and local manufacturers for providing us with the required materials for the completion of this work, with special mentions to Cerveses La Gardènia S.L (BSG suppliers), Centre Tecnològic Forestal de Catalunya (CTFC) (Boletus edulis and Armillaria mellea suppliers) and Horta Cal Marxant (pumpkin skin suppliers), Coselva S.C.C.L (OPC and nutshell suppliers), Pàmies Hortícoles (stevia branches suppliers) and Cámara Arrocera del Montsià (rice husk suppliers). We also acknowledge the effort and cooperation of all of the nutritionists involved in this project, and, especially, the aid of Dr. Rosa Maria Solà, Dr. Miguel Ángel Rodríguez and Dr. Juan Maria Alcaide. This study was performed with the cooperation of Unique Scientific and Technical Infrastructures (ICTS) of the Centre for Omic Sciences (COS), EURECAT-Technology Centre of Catalonia, Reus, Spain.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by ACCIO 2015 (RIS3CAT project).