Table 1: Effects of LCFAs in the pathogen recognition phase in IBD.

Pathogen recognition phaseThe type of LCFAsRole

Intestinal barrierDHA and EPAProtect the tight junctions while reducing MUC2 secretion
Palmitic acid and palm oilPromote MUC2 secretion
n-6 PUFAsReduce MUC2 secretion
TLR/NOD pathwayn-3 PUFAsUpregulate TLR-2 gene
n-9 PUFAsUpregulate TLR-4 gene
ALAInhibit the mRNA expression of TLR4, downregulate proinflammatory cytokines, upregulate anti-inflammatory cytokines, and decrease the mRNA expression of NOD
NF-κB pathwayFish oilDownregulate the NF-κB pathway
ALA, EPA, and DHADownregulate the NF-κB pathway
Oleic acidDownregulate the NF-κB pathway
PPAR-γ pathwayConjugated linoleic acidUpregulate the PPAR-γ pathway
DHA and EPAUpregulate the PPAR-γ pathway