In vitro fermentation of nuts results in the formation of butyrate and c9,t11 conjugated linoleic acid as chemopreventive metabolites

Eur J Nutr (2016) 55:20632073 DOI 10.1007/s00394-015-1020-0

ORIGINAL CONTRIBUTION

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Web End = In vitro fermentation of nuts results in the formation of butyrate and c9,t11 conjugated linoleic acid as chemopreventive metabolites

W. Schlrmann1 M. Birringer2 A. Lochner3 S. Lorkowski4,5 I. Richter2 C. Rohrer3,5 M. Glei1,5

Abstract

Purpose The consumption of foods rich in dietary ber and polyunsaturated fatty acids such as nuts can contribute to a healthy diet. Therefore, the formation of fermentation end-products which might exert chemopreventive effects regarding colon cancer was investigated after an in vitro simulated digestion and fermentation of nuts using human fecal microbiota.

Methods Fermentation supernatants (FS) and pellets (FP) were obtained after an in vitro fermentation of hazelnuts, almonds, macadamia, pistachios and walnuts. Short-chain fatty acids (SCFA) and bile acids (BA) in FS as well as fatty acids in FP were analyzed via gas chromatography. Malondialdehyde (MDA) levels in FS were determined photometrically.

Electronic supplementary material The online version of this article (doi:http://dx.doi.org/10.1007/s00394-015-1020-0

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* W. Schlrmann [email protected]

1 Department of Nutritional Toxicology, Institute of Nutrition, Friedrich Schiller University Jena, Dornburger Strae 24, 07743 Jena, Germany

2 Department of Nutritional, Food and Consumer Studies, University of Applied Sciences, Leipziger Strae 123, 36037 Fulda, Germany

3 Department of Nutritional Physiology, Institute of Nutrition, Friedrich Schiller University Jena, Dornburger Strae 24, 07743 Jena, Germany

4 Department of Nutritional Biochemistry and Physiology, Institute of Nutrition, Friedrich Schiller University Jena, Dornburger Strae 25, 07743 Jena, Germany

5 Competence Cluster for Nutrition and Cardiovascular Health (nutriCARD), Halle-Jena-Leipzig, 07743 Jena, Germany

Received: 1 July 2015 / Accepted: 10 August 2015 / Published online: 19 August 2015 Springer-Verlag Berlin Heidelberg 2015

Results Fermentation of nuts resulted in 1.9- to 2.8-fold higher concentrations of SCFA compared to the control and a shift of molar ratios toward butyrate production. In vitro fermentation resulted in the formation of vaccenic acid (C18:1t11, 32.1 3.2 % FAME; fatty acid methyl ester)

and conjugated linoleic acid (c9,t11 CLA, 2.4 0.7 %

FAME) exclusively in fermented walnut samples. Concentrations of secondary BA deoxycholic-/iso-deoxycholic acid (6.824.1-fold/4.910.9-fold, respectively) and levels of MDA (1.3-fold) were signicantly reduced in fermented nut samples compared to the control.

Conclusion This is the...