Dietary effects of ω3-fatty acids on intestinal transport function

Animals were fed for 2 weeks on one of four isocaloric and isocholesterolic semisynthetic diets: high 18:3ω3, low 18:3ω3, high 20:5ω3, or low 20:5ω3. The weight of the intestine and the percentage of the wall consisting of mucosa was greater in high 20:5ω3 than in high 18:3ω3, and greater in low 20:5ω3 than in low 18:3ω3, although the mucosal surface area was 26% lower in high 20:5ω3 than high 18:3ω3. The jejunal uptake of 40 mM glucose and ileal uptake of 40 mM galactose was greater in high 18:3ω3 than in high 20:5ω3; jejunal uptake of fatty acid 12:0 was higher, but 18:0 was lower in high 18:3ω3 than in high 20:5ω3. The jejunal or ileal uptake of cholesterol was not affected by 20:5ω3. However, 20:5ω3 had a variable effect on the uptake of medium- and long-chain fatty acids. Alterations in the uptake of fatty acids and glucose were not explained by any difference in the animals' food consumption, body weight gain, or intestinal weight, but the reduced jejunal uptake of 40 mM glucose in rats fed the high 20:5ω3 diet was associated with reduced mucosal surface area. Thus, (i) varying the source of ω3-fatty acids (vegetable, 18:3ω3 versus fish oil, 20:5ω3) altered the mucosal mass of the intestine, and (ii) the source of the dietary ω3-fatty acid (18:3ω3 versus 20:5ω3) influenced intestinal hexose uptake, with fish oil having an anti-absorptive effect on the jejunal uptake of D-glucose.