Fermented palm kernel meal modulates gut barrier and inflammatory gene via short-chain fatty acid production in broiler chickens

This study investigated the effects of dietary inclusion of fermented palm kernel meal ( FPKM ), produced using Limosilactobacillus fermentum BN21, on growth performance, jejunal histomorphology, cecal short-chain fatty acid ( SCFA ) production, and the expression of genes related to intestinal barrier function and inflammation in broiler chickens. A total of 320-day-old male broilers were randomly allocated to five dietary treatments containing 0, 25, 50, 75, or 100 g/kg FPKM. Each treatment consisted of eight replicate pens with eight birds per pen, and the pen was considered the experimental unit. Experimental diets were fed from day 11 to 35, covering the grower (days 11–21) and finisher (days 22–35) phases. Dietary inclusion of FPKM up to 75 g/kg did not impair growth performance, whereas 100 g/kg FPKM significantly reduced weight gain and increased feed conversion ratio ( P < 0.05). The villus height-to-crypt depth ( VH:CD ) ratio was significantly higher in the 25 and 50 g/kg FPKM groups, although villus height and crypt depth were unchanged. Cecal concentrations of acetate, propionate, butyrate, and total SCFAs increased linearly with FPKM levels ( P < 0.05). Supplementation with FPKM also downregulated claudin-1 ( CLDN-1 ) and upregulated zonula occludens-1 ( ZO-1 ) ( P < 0.05). Expression of interleukin-18 ( IL-18 ) decreased, whereas interleukin-10 ( IL-10 ) and interleukin-13 ( IL-13 ) were upregulated ( P < 0.001). These findings indicate that dietary inclusion of 50 g/kg FPKM fermented by L. fermentum BN21 improves intestinal health by enhancing SCFA production, intestinal morphology, and immune-related gene expression without compromising growth performance in broilers.