Omega-3 polyunsaturated fatty acids improve intestinal barrier integrity—albeit to a lesser degree than short-chain fatty acids: an exploratory analysis of the randomized controlled LIBRE trial
Benjamin Seethaler, Katja Lehnert, Maryam Yahiaoui‐Doktor, Maryam Basrai, Walter Vetter, Marion Kiechle, Stephan C. Bischoff
Abstract
Abstract Purpose Adherence to the Mediterranean diet is associated with beneficial health effects, including gastrointestinal disorders. Preclinical studies suggest that omega-3 polyunsaturated fatty acids ( n -3 PUFAs), found in Mediterranean foods like nuts and fish, improve intestinal barrier integrity. Here, we assessed possible effects of n -3 PUFAs on barrier integrity in a randomized controlled trial. Methods We studied 68 women from the open-label LIBRE trial (clinicaltrials.gov: NCT02087592) who followed either a Mediterranean diet (intervention group, IG) or a standard diet (control group, CG). Study visits comprised baseline, month 3, and month 12. Barrier integrity was assessed by plasma lipopolysaccharide binding protein (LBP) and fecal zonulin; fatty acids by gas chromatography with mass spectrometry. Median and interquartile ranges are shown. Results Adherence to the Mediterranean diet increased the proportion of the n -3 docosahexaenoic acid (DHA) (IG + 1.5% [0.9;2.5, p < 0.001]/ + 0.3% [− 0.1;0.9, p < 0.050] after 3/12 months; CG + 0.9% [0.5;1.6, p < 0.001]/ ± 0%) and decreased plasma LBP (IG − 0.3 µg/ml [− 0.6;0.1, p < 0.010]/ − 0.3 µg/ml [− 1.1; − 0.1, p < 0.001]; CG − 0.2 µg/ml [− 0.8; − 0.1, p < 0.001]/ ± 0 µg/ml) and fecal zonulin levels (IG − 76 ng/mg [− 164; − 12, p < 0.010]/ − 74 ng/mg [− 197;15, p < 0.001]; CG − 59 ng/mg [− 186;15, p < 0.050]/ + 10 ng/mg [− 117;24, p > 0.050]). Plasma DHA and LBP ( R 2 : 0.14–0.42; all p < 0.070), as well as plasma DHA and fecal zonulin ( R 2 : 0.18–0.48; all p < 0.050) were found to be inversely associated in bi- and multivariate analyses. Further multivariate analyses showed that the effect of DHA on barrier integrity was less pronounced than the effect of fecal short-chain fatty acids on barrier integrity. Conclusions Our data show that n -3 PUFAs can improve intestinal barrier integrity. Trial registration number : The trial was registered prospectively at ClinicalTrials.gov (reference: NCT02087592).