Abstract
Nutritional support using exclusive enteral nutrition (EEN) has been studied as primary therapy for the management of liver diseases, Crohn's disease, and cancers. EEN can also increase the number of beneficial microbiotas in the gut, improve bile acid and lipid metabolism, and decrease the number of harmful dietary micro-particles, possibly by influencing disease occurrence and increasing immunity. This study investigated the effects of EEN-n-3 polyunsaturated fatty acids (3PUFAs) (EEN-3PUFAs) on the gut microbiome, intestinal barrier, and lipid or bile acid metabolism in mice. Metagenomic sequencing technology was used to analyze the effects of EEN-3PUFAs on the composition of gut microbiome signatures. The contents of short-chain fatty acids (SCFAs) and bile acids in the feces and liver of the mice were assayed by gas chromatography and ultra-high-pressure liquid chromatography/high-resolution tandem mass spectrometry, respectively. The levels of lipopolysaccharide (LPS) and D-lactic acid in the blood were used to assess intestinal permeability. The results indicated that EEN-3PUFAs could improve the composition of gut microbiome signatures and increase the abundance of Barnesiella and Lactobacillus (genus), Porphyromonadaceae, and Bacteroidia (species), and Bacteroidetes (phylum) after EEN-3PUFAs initiation. In addition, EEN-3PUFAs induced the formation of SCFAs (mainly including acetic acid, propionic acid, and butyric acid) and increased the intestinal wall compared to the control group. In conclusion, EEN-3PUFAs modulate the alterations in gut microbiome signatures, enhanced intestinal barrier, and regulated the fatty acid composition and lipid metabolism shifts and the putative mechanisms underlying these effects.