Linoelaidic acid gavage has more severe consequences on triglycerides Accumulation, inflammation and intestinal microbiota in mice than elaidic acid

This work aims to study the effects of oral gavage (0.2 mg/g body weight) of elaidic acid (C18:1–9 t, EA) and linoelaidic acid (C18:2–9 t,12 t, LEA) on lipid metabolism, inflammation and gut homeostasis of mice. Results showed that both EA and LEA gavage significantly increased LDL-c, TC and oxidative stress levels in the liver and serum and may stimulated liver inflammation via NF-κB and MAPK signaling pathway. Compared with EA, LEA gavage significantly promoted TAG accumulation and inflammatory signaling. Serum lipidomics revealed that LEA intake significantly increased the concentration of ∼50 TAGs, while EA gavage primarily caused significant decreases in several SMs. 16S rRNA demonstrated that LEA ingestion markedly changed fecal microbiota by enriching Lactobacillus (phylum Firmicutes), however, EA treatment did not affect it. Overall, LEA gavage has more severe consequences on TAG accumulation, inflammation and microbial structure than EA, highlighting that the number of trans double bonds affects these processes.