A randomised trial of the effect of omega-3 polyunsaturated fatty acid supplements on the human intestinal microbiota.

Abstract

OBJECTIVE:

Omega-3 polyunsaturated fatty acids (PUFAs) have anticolorectal cancer (CRC) activity. The intestinal microbiota has been implicated in colorectal carcinogenesis. Dietary omega-3 PUFAs alter the mouse intestinal microbiome compatible with antineoplastic activity. Therefore, we investigated the effect of omega-3 PUFA supplements on the faecal microbiome in middle-aged, healthy volunteers (n=22).

DESIGN:

A randomised, open-label, cross-over trial of 8 weeks' treatment with 4 g mixed eicosapentaenoic acid/docosahexaenoic acid in two formulations (soft-gel capsules and Smartfish drinks), separated by a 12-week 'washout' period. Faecal samples were collected at five time-points for microbiome analysis by 16S ribosomal RNA PCR and Illumina MiSeq sequencing. Red blood cell (RBC) fatty acid analysis was performed by liquid chromatography tandem mass spectrometry.

RESULTS:

Both omega-3 PUFA formulations induced similar changes in RBC fatty acid content, except that drinks were associated with a larger, and more prolonged, decrease in omega-6 PUFA arachidonic acid than the capsule intervention (p=0.02). There were no significant changes in α or β diversity, or phyla composition, associated with omega-3 PUFA supplementation. However, a reversible increased abundance of several genera, including Bifidobacterium, Roseburia and Lactobacillus was observed with one or both omega-3 PUFA interventions. Microbiome changes did not correlate with RBC omega-3 PUFA incorporation or development of omega-3 PUFA-induced diarrhoea. There were no treatment order effects.

CONCLUSION:

Omega-3 PUFA supplementation induces a reversible increase in several short-chain fatty acid-producing bacteria, independently of the method of administration. There is no simple relationship between the intestinal microbiome and systemic omega-3 PUFA exposure.

TRIAL REGISTRATION NUMBER:

ISRCTN18662143.

• Authors: Henry Watson, Suparna Mitra, Fiona C Croden, Morag Taylor, Henry M Wood, Sarah L Perry, Jade A Spencer, Phil Quirke, Giles J Toogood, Clare L Lawton, Louise Dye, Paul M Loadman, Mark A Hull
• Journal: Gut (Gut) Vol. 67 Issue 11 Pg. 1974-1983 (11 2018) ISSN: 1468-3288 [Electronic] England
• PMID: 28951525 (Publication Type: Journal Article, Randomized Controlled Trial, Research Support, Non-U.S. Gov't)
• Copyright: © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Chemical References

• Fatty Acids
• Fatty Acids, Omega-3

Topics

• Aged
• Chromatography, Liquid
• Cross-Over Studies
• Dietary Supplements
• Fatty Acids (blood)
• Fatty Acids, Omega-3 (therapeutic use)
• Feces (microbiology)
• Female
• Gastrointestinal Microbiome (drug effects)
• Healthy Volunteers
• Humans
• Male
• Mass Spectrometry
• Middle Aged
• Polymerase Chain Reaction