The effects of dietary fats on the intestinal barrier have been widely studied, yet their role in intestinal repair remains unclear. Previous studies have primarily focused on fat quantity (e.g., high-fat vs. low-fat diets) and quality (e.g., saturated vs. unsaturated fats), while neglecting the importance of structural properties. This study evaluated the impact of dietary fats with varying sn-2 palmitate levels on intestinal repair using a DSS-induced murine injury model under moderate intake levels. The results indicated that lard, rich in sn-2 palmitate, significantly lowered intestinal permeability, reduced crypt damage, and decreased apoptosis in mice compared to fats low in sn-2 palmitate (corn oil and beef tallow). Immunohistochemical analysis demonstrated that lard significantly increased the number of SOX9, Ki67, MUC2, and PAS-positive cells per crypt, indicating enhanced proliferation and differentiation of intestinal stem/progenitor cells, thereby facilitating intestinal repair. Untargeted metabolomics analysis revealed distinct metabolic profiles of intestinal digestive products derived from dietary fats, with lard leading to enrichment of metabolites such as diacylglycerols, palmitoylcarnitine, and adhumulinic acid. The microbial results showed that lard improved α-diversity and increased the abundance of beneficial bacteria such as unclassified_Lachnospiraceae, unclassified_Muribaculaceae, and Ligilactobacillus. KEGG pathway analysis further demonstrated that lard enriched microbial pathways associated with replication and repair, translation, and amino acid metabolism. Our findings reveal that moderate intake of lard promotes intestinal repair, which is associated with beneficial shifts in metabolite profiles and gut microbiota composition. These results highlight the significance of the sn-2 palmitate structure in dietary fat interventions for promoting intestinal repair.

The association between dietary fat types and obesity is controversial, and the underlying mechanism remains unclear. This study aimed to evaluate the effect of different dietary fat sources (lard, corn oil or canola oil) on obesity in mice. The results revealed that lard-fed mice showed a lean phenotype, as well as lower serum cholesterol level compared with mice fed corn oil or canola oil. The 16S rRNA gene sequencing showed that the lard-fed mice had higher α-diversity of gut microbiota. In addition, the lard group had similar relative abundance of Lactobacillus, unclassified_f_Lachnospiraceae and Bacteroides compared with the control group. Targeted metabolomics analysis of caecal bile acid (BA) profile suggested the levels of chenodeoxycholic acid, lithocholic acid, deoxycholic acid and cholic acid in the lard group were higher than those in the corn oil and canola oil groups. Meanwhile, the levels of BA receptor farnesoid X receptor (Fxr) gene in lard-fed mice were higher than vegetable oil groups. These results suggested that lard could reduce the risk of obesity compared with corn oil and canola oil, which may be associated with more balanced gut microbiota and BA composition as well as activated FXR signaling.