Open Access Short report

Eicosapentaenoic and docosahexaenoic acid supplementation and inflammatory gene expression in the duodenum of obese patients with type 2 diabetes

Marie-Ève Labonté1, Patrick Couture1, André J Tremblay1, Jean-Charles Hogue1, Valéry Lemelin2 and Benoît Lamarche1*

Author Affiliations

1 Institute of Nutrition and Functional Foods, Laval University, 2440 boul. Hochelaga, Québec (Qc) G1V 0A6, Canada

2 Department of Gastroenterology, Laval University Hospital Research Center, 2705, boul. Laurier, Québec (Qc) G1V 4G2, Canada

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Nutrition Journal 2013, 12:98  doi:10.1186/1475-2891-12-98

Published: 15 July 2013

Abstract

Background

The extent to which long-chain omega-3 polyunsaturated fatty acids (LCn-3PUFA) from fish oil such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) exert their anti-inflammatory effects by down-regulating intestinal inflammation in humans is unknown. We investigated the impact of LCn-3PUFA supplementation on inflammatory gene expression in the duodenum of obese patients with type 2 diabetes.

Findings

This placebo-controlled randomized crossover study included 12 men with type 2 diabetes. After a 4-week run-in period, patients received in a random sequence 5 g/d of fish oil (providing 3 g of EPA + DHA) and a placebo (corn and soybean oil) for 8 weeks each. The two treatment phases were separated by a 12-week washout period. Gene expression was assessed by real-time polymerase chain reaction in duodenal biopsy samples obtained in the fasted state at the end of each treatment phase. Intestinal mRNA expression levels of interleukin (IL)-6 and tumor-necrosis factor (TNF)-α were hardly detectable after either treatment (<100 copies/105 copies of the reference gene ATP5o). Intestinal mRNA expression of IL-18 and of the transcription factor signal transducer and activator of transcription 3 (STAT3) was higher (>5000 copies/105 copies ATP5o) but still relatively low. EPA + DHA supplementation had no impact on any of these levels (all P ≥ 0.73).

Conclusions

These data suggest that duodenal cells gene expression of pro-inflammatory cytokines is low in patients with type 2 diabetes and not affected by EPA + DHA supplementation. Further studies are warranted to determine if inflammatory gene expression in other tissues surrounding the intestine is modulated by EPA + DHA supplementation.

Trial registration

ClinicalTrials.gov ID: NCT01449773

Keywords:
Eicosapentaenoic acid (EPA); Docosahexaenoic acid (DHA); Signal transducer and activator of transcription 3 (STAT3); Inflammatory gene expression; n-3 supplementation; Placebo-controlled; Duodenum; Type 2 diabetes