Effect of Gum Acacia on the Intestinal Bioavailability of n-3 Polyunsaturated Fatty Acids in Rats

Abstract

Lipid emulsification is a technique that is being explored for improving the bioavailability of omega 3 (n-3) long chain (LC) fatty acid (FA). The nature of the emulsifiers can differently impact the lipid bioavailability via a modification of the lipolysis step. Among natural emulsifiers, gum acacia (GA), an indigestible polysaccharide, provides protective encapsulation of n-3 by forming a specifically crown-like shape around lipid drops, which could also impact the digestion step. Despite the interest in lipolysis rate, the impact of GA on lipid bioavailability has never been explored in a complete physiological context. Thus, we followed in a kinetics study the n-3 bioavailability in rat lymph, orally administered DHA-rich oil, formulated based on GA compared to the bulk phase form of the oil. The AUC values were significantly improved by +121% for total TG and by 321% for n-3 PUFA, specifically for EPA (+244%) and for DHA (+345%). Benefits of GA have also been related to the transport of FA in lymph, which was 2 h earlier (Tmax = 4 h), compared to the Tmax (6 h) obtained with the bulk phase oil. All the data showed that GA is one of the most favorable candidates of natural emulsifiers to improve n-3 bioavailability and their rate of absorption for health targets.

Role of encapsulation on the bioavailability of omega‐3 fatty acids

“…In an animal study, rats could easily absorb ALA from the ingested PUFA oil powder‐supplemented diet and had significantly increased plasma ALA and EPA (Kaushik et al., 2015; Yoshikiyo et al., 2019). Another study on rats proved encapsulated omega‐3 PUFA oil showed bioavailability 2.5–3 times more than the bulk oil when assessed by the total FA concentration in the lymph (Couëdelo et al., 2022). The wall materials protect PUFA not only against environmental pro‐oxidants but also against the breakdown or destruction of omega‐3 PUFA by GI conditions like low pH and gastric enzymes before it reaches the small intestine for digestion, thus leading to controlled release and retention of functionality (Hu et al., 2021).…”

“…Emulsifiers have varying effects on lipid digestion because their characteristic surface activity alters the enzyme activity and rate of lipolysis (Lamothe et al., 2020; McClements et al., 2016). Casein and Tween (Tween 20 and Tween 80) slow down lipolysis and decrease the bioavailability of FA, but lecithin increases FA bioavailability by favoring the digestion step at its initiation (Couëdelo et al., 2022; Li et al., 2020; Sehl et al., 2020). The lipase cannot bind to the surface of the oil droplet because Tween's intersurface action is greater than that of the lipase (Li et al., 2020).…”

“…The improvement can be attributed to the greater surface area available for lipases, bile salts, and other digestive enzymes to act on emulsified and encapsulated oil (McClements, 2021; McClements et al., 2016; Venugopalan et al., 2021). Studies have demonstrated that enhanced lipolysis caused by the production of multiple small PUFA globules increases the bioavailability of FA due to their increased surface area (Couëdelo et al., 2022; Gayoso et al., 2019). Moreover, smaller particle size results in a thinner diffusion layer, which speeds up transport through the epithelial layer and dissolves more quickly (Blanco‐Llamero et al., 2022; Hu et al., 2021).…”

“…Various studies show how different matrices perform during digestion with regard to core release. For instance, the addition of fiber in the matrix would delay the rate of intestinal nutrient absorption, which could be negative because it would result in less absorption of important FA (Couëdelo et al., 2022). However, researchers have also shown that including fiber as a wall component can improve the integrity of the emulsion during heat processing, such as spray drying, because fiber may shield the protein‐based wall material from denaturation (Chen et al., 2013).…”

“…Bulk forms of oils present limited bioaccessibility of PUFAs found in the oil (Ahmmed et al., 2020). Encapsulation also solves the issue of low PUFA absorption and improves the therapeutic potential of fats and oils as it results in the controlled release of lipids in the GI tract and increased bioavailability and uptake during intestinal digestion (Blanco‐Llamero et al., 2022; Couëdelo et al., 2022). The mechanisms of improved bioavailability of PUFA from encapsulated oils are explained in Section 6 of this article.…”