Anaerobe. 2014 Apr;26:1-6. doi: 10.1016/j.anaerobe.2013.11.007. Epub 2013 Dec 3.

Prebiotic effects of almonds and almond skins on intestinal microbiota in healthy adult humans.

Liu Z1, Lin X1, Huang G2, Zhang W1, Rao P1, Ni L3.

• 1Institute of Food Science & Technology, Fuzhou University, No. 2 Xueyuan Road, Fuzhou 350108, PR China.
• 2Almond Board of California, 1150 9th Street, Suite 1500, Modesto, CA 95354, USA.
• 3Institute of Food Science & Technology, Fuzhou University, No. 2 Xueyuan Road, Fuzhou 350108, PR China. Electronic address: nili@fzu.edu.cn.

Abstract

Almonds and almond skins are rich in fiber and other components that have potential prebiotic properties. In this study we investigated the prebiotic effects of almond and almond skin intake in healthy humans. A total of 48 healthy adult volunteers consumed a daily dose of roasted almonds (56 g), almond skins (10 g), or commercial fructooligosaccharides (8 g) (as positive control) for 6 weeks. Fecal samples were collected at defined time points and analyzed for microbiota composition and selected indicators of microbial activity. Different strains of intestinal bacteria had varying degrees of growth sensitivity to almonds or almond skins. Significant increases in the populations of Bifidobacterium spp. and Lactobacillus spp. were observed in fecal samples as a consequence of almond or almond skin supplementation. However, the populations of Escherichia coli did not change significantly, while the growth of the pathogen Clostridum perfringens was significantly repressed. Modification of the intestinal microbiota composition induced changes in bacterial enzyme activities, specifically a significant increase in fecal β-galactosidase activity and decreases in fecal β-glucuronidase, nitroreductase and azoreductase activities. Our observations suggest that almond and almond skin ingestion may lead to an improvement in the intestinal microbiota profile and a modification of the intestinal bacterial activities, which would induce the promotion of health beneficial factors and the inhibition of harmful factors. Thus we believe that almonds and almond skins possess potential prebiotic properties.

Copyright © 2013 Elsevier Ltd. All rights reserved.

KEYWORDS:

Almond; Almond skins; Bacterial enzymes; Intestinal microbiota; Prebiotics

PMID:

24315808