Monoacylglycerol-enriched oil increases EPA/DHA delivery to circulatory system in humans with induced lipid malabsorption conditions

Abstract

This article is available online at http://www.jlr.org Dietary fats are not only a source of energy, but also of bioactive nutrients, which are essential in maintaining human health. Among the fats, some FAs are considered essential FAs (EFAs) because they are not de novo synthesized and humans lack the enzymes required for their biosynthesis. Dietary fat absorption involves two main steps: first, lipolysis of dietary triacylglycerol (TAG) by sn-1,3' specific gastric and (colipase-dependent) pancreatic lipases to release two FFAs, and an sn-2 monoacylglycerol (MAG); and second, the formation of micellar structures (via association of intraluminal conjugated bile salts and lipolytic products), which aid enteral uptake (1, 2). Conventional knowledge indicates that FAs at the sn-1 and -3 positions are hydrolyzed and sn-2 FA is absorbed directly as monoglycerides; as such, the stereospecific position of FAs on the TAG backbone plays an important role in determining the uptake and metabolic fate of a particular FA (especially EFA) (1, 3). FAs such as linoleic acid (LA) and -linolenic acid (ALA) are EFAs, and dietary ALA can be metabolically converted to other long-chain PUFAs (LC-PUFAs), such as DHA and EPA, with recognized beneficial health effects. However, the efficiency of enzymatic conversion from ALA to DHA/EPA appears to be relatively low in humans (4). Therefore, larger quantities of DHA/EPA may be obtained from dietary sources such as fatty fish for ultimate health benefit. Among their health benefits, EPA and DHA are cardioprotective and have a positive impact on inflammatory conditions by interfering with the production of systemic inflammatory mediators, such as leukotrienes, platelet-activating factor, interleukin-l, and tumor necrosis factor (5-7). Impairment of intestinal uptake of fat in

Monoacylglycerol Form of Omega-3s Improves Its Bioavailability in Humans Compared to Other Forms

“…Indeed, it has been suggested that this type of persistent malabsorption is not only due to insufficient enzymes but also due to incomplete intraluminal solubilization or reduced enterocyte uptake, or both [33,35,36]. Studies suggest that OM3 LC-PUFA may be anti-inflammatory and a benefit for cystic fibrosis patients, and that the MAG form exhibits a higher degree of efficient absorption than the TAG form [20][21][22][23]28,33,35,36].…”

“…Interestingly, OM3 was shown to be an effective substrate to MGAT enzyme and could be used as a pre-digested fat [37,38] with potentially improved bioavailability compared to ethyl ester or TAG. This lipase-independent MAG carrier may offer a clinical advantage to patients struggling with fat malabsorption/maldigestion problems, for instance, patients with cystic fibrosis [21,[37][38][39].…”

“…Blood was collected in 1.2 mL (4 mL for clinical trial A and B) Ethylenediaminetetraacetic acid (EDTA)-containing S-Monovette K3 (Sarstedt # 02.1066.001). Plasma was separated from erythrocytes by single centrifugation as previously applied [21,41], no further centrifugation was applied to the erythrocytes fraction obtained [42]. Sample preparation for fatty acid methyl esters (FAME) analysis was done as previously described [21].…”

“…Plasma was separated from erythrocytes by single centrifugation as previously applied [21,41], no further centrifugation was applied to the erythrocytes fraction obtained [42]. Sample preparation for fatty acid methyl esters (FAME) analysis was done as previously described [21]. Blood fractions were kept on ice during sample preparation and finally stored at −80 • C until FA analysis.…”

“…Therefore, it is recommended to include sources of OM3-long chain polyunsaturated fatty acids (LC-PUFAs), such as fatty fish, in one's diet in order to obtain the desired health benefits [15,[17][18][19]. Several bioavailability studies have been devoted to the actions of different sources of LC-PUFAs (e.g., fatty fish versus supplements) or different carriers (e.g., triacylglycerol (TAG), MAG, ethyl ester, FFA, and phospholipids) [5,6,12,[20][21][22][23]. During the digestion of the ethyl ester carrier, the ethyl group is hydrolyzed by lipases, and the resulting fatty acid (FA) is then converted back into a TAG molecule ( Figure 1) before being transported by the lymphatic system [24,25].…”