Objective: Recent research on marine lecithin has demonstrated their ability to modulate fatty acid bioavailability and postprandial lipemia, but data concerning vegetable lecithin is lacking. Our objective was to evaluate the impact of nutritional doses of plant lecithin alternative to soy on lipid metabolism, the bioavailability of an essential plant lipid, alpha-linolenic acid (ALA), and gut microbiota.
Methods used: Male Swiss mice (n=60) were fed normolipidic diets (identical ALA content) containing 0, 1, 3 or 10% rapeseed lecithin (RL) or 10% soy lecithin for 5 days. Following a fast, the mice were force-fed the same oil mix and euthanised after 90 min. As a mechanistic study, male Wistar rats (n=30) with mesenteric duct cannulation were fed oil mixtures with 0 to 20% RL. Lymph fractions were collected for 6h post-gavage. Plasma and lymph lipid analysis was performed using GC-FID, and gene expression and microbiota composition via RT-qPCR.
Results: In mice, lecithin increased faecal Clostridium leptum levels, regardless of dose or origin. The consumption of lecithin did not alter plasma lipids nor the expression of genes of hepatic or intestinal lipid metabolism. The percentage of ALA in plasma triacylglycerides, but not phospholipids, was significantly higher in the 10% RL group compared to other groups. In rats, RL significantly and dose-dependently increased the rate of appearance of ALA in lymph.
Conclusions: Our results suggest that, in rodents, both rapeseed and soy lecithin improved gut microbiota composition by increasing Clostridium leptum. Only rapeseed lecithin, however, enhanced ALA bioavailability. Underlying mechanisms must be explored.