Dietary intake of n-3 PUFAs modifies the absorption, distribution and bioavailability of fatty acids in the mouse gastrointestinal tract

Qin Yang,Hao Zhang,Shunhe Wang,Yunqi Ji,Wei Chen,Yong Q Chen,Haiqin Chen,Zhennan Gu

doi:10.1186/s12944-016-0399-9

Abstract

BackgroundDietary polyunsaturated fatty acids (PUFAs), especially n-3 PUFAs, are important for human health. The intestinal tract, a location that is heavily colonized by microorganisms, is the main organ for absorbing fatty acids.MethodsThe purpose of this study was to analyze the effects of dietary n-3 and n-6 PUFAs on the distribution of different types of fatty acids and their bioavailability along the gut. Mice were fed for a week with experimental diets containing high n-3 or high n-6 fatty acid levels. Blood was collected at different time points, and after 7 days the mice were euthanized and their digestive tract was divided into 17 segments for fatty acids analyses.ResultsWe found that supplementing n-3 fatty acids significantly changed the ratio of n-6/n-3 PUFAs, increased the bioavailability of n-3 PUFAs, and altered fatty acid distribution. In addition, in the n-3 diet group, the absorption of saturated fatty acids (SFAs) along the gut was found to be inhibited, which was confirmed by feeding the mice with a diet containing deuterium-labeled palmitic acid and stearic acid.ConclusionThese results show that a diet rich in n-3 PUFAs can significantly modify the distribution and bioavailability of fatty acids, and particularly, may block the absorption of SFAs in the mouse gastrointestinal (GI) tract.

Highlights

Dietary polyunsaturated fatty acids (PUFAs), especially n-3 PUFAs, are important for human health
Total levels of PUFAs, monounsaturated fatty acids (MUFAs) and saturated fatty acids (SFAs) were similar to the fatty acid composition of the respective diets (Additional file 1: Table S1)
We found that total PUFA levels decreased, while total MUFA levels increased along the intestinal tract in both n-3 and n-6 diet groups

Summary

Introduction

Dietary polyunsaturated fatty acids (PUFAs), especially n-3 PUFAs, are important for human health. Dietary lipids are important for human health, providing caloric energy, and taking part in vital cellular functions. High fat consumption and high ratios of n-6/n-3 polyunsaturated fatty acids (PUFAs) in the Western diet are associated with an increased incidence of obesity, diabetes, cardiovascular disease and cancer [1, 2]. While the genetic background influences dietary lipid absorption and metabolism [6], evidence suggest that the gut microenvironment, including its complicated environment and the gut microbiota, plays an important role in fat digestion, absorption and metabolism [7, 8]. The bioavailability of fatty acids is associated with gastrointestinal function, and alterations in their metabolism may cause mucosal inflammation and other gastrointestinal troubles [9]. Supplementation of n-3 PUFAs can improve gut function via interaction with the gut microbiota [10]

Objectives

Methods

Results

Discussion

Conclusion