Lemongrass (Cymbopogon citratus) supplementation improves growth performance, intestinal function and inflammation...

This study investigated the effects of dietary lemongrass (Cymbopogon citratus) supplementation on growth performance, intestinal morphology, and inflammation in weaned piglets. Twenty-one weaned pigs (Duroc × Landrace × Yorkshire, 21 d of age, initial body weight [IBW] = 7.70 ± 0.25 kg, n = 7 per group) were assigned to one of three dietary treatments: a basal diet, a basal diet supplemented with 0.1% lemongrass (LCC), or a basal diet supplemented with 0.5% lemongrass (HCC). The trial lasted for 28 d. Multi-omics approaches, including microbiomics, metabolomics, and transcriptomics, were employed to explore the underlying mechanisms. The results demonstrated that dietary lemongrass improved growth performance and intestinal morphology (P < 0.001). Microbiota profiling revealed that lemongrass increased the beta diversity of gut bacteria and fungi in the ileal content. Notably, dietary lemongrass enhanced the relative abundances of beneficial microbiotas such as Lactobacillus reuteri (P = 0.045), Weissella paramesenteroides (P = 0.047), and Kazachstania slooffiae (P = 0.037). In addition, lemongrass enhanced amino acid and lipid metabolic pathways in the ileum, as evidenced by changes in related metabolite contents. Transcriptomic analysis further identified the up-regulation of genes associated with nutrient metabolism and immune signaling. Correlation analysis highlighted strong associations among microbial composition, metabolite abundance, and gene expression related to nutrient metabolism. These effects were further supported by reduced levels of inflammatory cytokines in both serum and ileal tissue (P < 0.001), accompanied by enhanced lipase (P = 0.004) and trypsin (P = 0.002) activities. Collectively, these results indicate that dietary lemongrass improves growth performance, intestinal morphology, digestive function, inflammatory status, and microbiota composition, suggesting its potential as a promising natural alternative to antibiotics.