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

• Published in: Gut Vol. 67; no. 11; pp. 1974 - 1983
• Main Authors: Watson, Henry, Mitra, Suparna, Croden, Fiona C, Taylor, Morag, Wood, Henry M, Perry, Sarah L, Spencer, Jade A, Quirke, Phil, Toogood, Giles J, Lawton, Clare L, Dye, Louise, Loadman, Paul M, Hull, Mark A
• Format: Journal Article
• Language: English
• Published: England BMJ Publishing Group LTD 01.11.2018
• Subjects: Aged; Arachidonic acid; Beverages; Cancer; Carcinogenesis; Chromatography, Liquid; Colorectal cancer; Cross-Over Studies; Diarrhea; Diet; Dietary Supplements; Docosahexaenoic acid; Eicosapentaenoic acid; Erythrocytes; Fatty acids; Fatty Acids - blood; Fatty Acids, Omega-3 - therapeutic use; Feces - microbiology; Female; Fish oils; Functional foods & nutraceuticals; Gastrointestinal Microbiome - drug effects; Healthy Volunteers; Humans; Hypotheses; Intervention; Intestinal microflora; Intestine; Liquid chromatography; Male; Mass Spectrometry; Mass spectroscopy; Metabolism; Metabolites; Microbiomes; Microbiota; Middle Aged; Nutrition research; Ostomy; Polymerase Chain Reaction; Polyunsaturated fatty acids; rRNA 16S; fatty acid; colorectal cancer; bacteria; nutritional supplement; omega-3
• DOI: 10.1136/gutjnl-2017-314968
• ISSN: 0017-5749; 1468-3288

ObjectiveOmega-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).DesignA 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.ResultsBoth 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.ConclusionOmega-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 numberISRCTN18662143.