This study aimed to investigate the effect of Bacillus toyonensis BCT-7112^T supplementation on growth performance, intestinal morphology, immune-related gene expression, and the cecal microbiota of meat ducks. A total of 150 one-day-old male Barbary ducks were divided into 3 groups with 5 replicates (n = 10 ducks per replicate) by completely randomized design and offered diets supplemented with the commercial product Toyocerin (containing 1 × 10⁹B. toyonensis BCT-7112^T viable spores/g product) at the levels of 0, 500, or 1,000 mg/kg (0, 500, or 1,000 ppm), respectively, for 8 wk. The results showed that although ducks in the 500 ppm B. toyonensis BCT-7112^T group displayed numerically better values (e.g., weight gain and feed conversion ratio) than those in the control group, the growth performance of ducks fed diets supplemented with B. toyonensis BCT-7112^T did not differ significantly from that of the control group (P > 0.05). There were no significant differences in the intestinal mucosal morphology of ducks across the experimental groups (P > 0.05). However, ducks in the 500 ppm B. toyonensis BCT-7112^T group showed a trend of greater values, for example, villus height per crypt depth of duodenum (P = 0.16) and ileum (P = 0.12) compared with those in the control group. The relative expression of immune-related genes, for example, interferon (IFN) and interleukin-6 (IL-6) in the meat duck spleen was significantly lower in both B. toyonensis BCT-7112^T groups at 14 d and 35 d than in the control group (P < 0.05). Beta diversity analysis of the cecal microbiota of ducks in either the 500 ppm or the 1,000 ppm B. toyonensis BCT-7112^T group showed to have higher diversity than that in the control group, where at the phylum level, Bacteroidetes was the most abundant, followed by Firmicutes, and at the genus level, Bacteroides, Fusobacterium, and Ruminococcaceae were the top 3 most abundant genera. In conclusion, our study demonstrates that 500 ppm supplementation with B. toyonensis BCT-7112^T in duck diets can reduce proinflammatory cytokine gene expression, improve immunological function, and increase the variety of microbial communities in the ceca of meat-type ducks.

Tiliacora triandra (Yanang) leaf contains polyphenols, flavonoids, and mucilage polysaccharides with antioxidant and prebiotic functions, making it a promising substrate for probiotic fermentation. This study aimed to optimize Yanang extraction and sterilization to preserve bioactive mucilage and support probiotic survivability during freeze-drying–based encapsulation, and evaluate antimicrobial activity against poultry pathogens. Yanang extract was prepared under different leaf processing conditions and used as a substrate for Pediococcus acidilactici V202, Lactiplantibacillus plantarum TISTR 926, Streptococcus thermophilus TISTR 894, Bacillus subtilis RP4-18, and Bacillus licheniformis 46-2. Fermentation at 37 °C for 24 h revealed that lactic acid bacteria (P. acidilactici V202, L. plantarum TISTR 926, S. thermophilus TISTR 894) reduced pH (<4.10, p < 0.001) while maintaining high viable counts (>8.67 log CFU/mL, p < 0.01), whereas Bacillus strains (B. subtilis RP4-18, B. licheniformis 46-2) retained a higher pH (>5.00) and lower viability ( 0.05), while compared with Bacillus strains (p < 0.01), lactic acid bacteria had superior tolerance to simulated gastrointestinal and thermal stress. Supernatant from Yanang extract inhibited B. cereus WU22001, S. aureus ATCC25923, Escherichia coli ATCC25922, and Salmonella typhimurium WU241001 (MIC/MBC 25–50% v/v). These results indicate that Yanang extract supports effective probiotic fermentation, and rice bran encapsulation enhances survivability and antimicrobial functionality for potential functional feed applications.

The poultry industry requires sustainable strategies to improve gut health and nutrient utilization while reducing antibiotic use. This study assessed the effects of dietary supplementation with a microencapsulated phytosynbiotic from Yanang (Tiliacora triandra) leaf extract fermented with Pediococcus acidilactici V202 (YEP) on broiler ileal digestibility, microbial viability, and cecal fermentation using an in vitro gastrointestinal simulation model. Six YEP inclusion levels (0–2.5%) were tested. Results revealed significant improvements in ileal dry matter and gross energy digestibility and enhanced survival and proliferation of beneficial lactic acid bacteria in the ileum. Increased gas production, lactic acid, and volatile fatty acid concentrations, including acetate, propionate, and butyrate, indicated that cecal fermentation was enhanced in a dose-dependent manner. Moderate YEP levels optimized fermentation speed and butyrate synthesis, while higher levels enhanced total gas and acetate production. YEP also shifted the cecal microbiota toward a healthier profile, enhancing Lactobacillaceae counts and the Lactobacillaceae-to-Enterobacteriaceae ratio. Overall, protective microencapsulation, synergistic phytochemical interactions, and balanced nutrient supply had positive effects at the gut level. Thus, the data highlight YEP as a promising synbiotic feed additive that can enhance nutrient utilization, microbial balance, and gut health in broilers, warranting future in vivo validation.

The global shift toward antibiotic-free poultry production has created an urgent need for sustainable feed additives that promote gut health and productivity. This study aimed to develop and evaluate a novel double-layered microencapsulated phytosynbiotic (DMP) comprising Tiliacora triandra extract, probiotics, and cereal by-products using lyophilization. In Experiment 1, we investigated the effects of cell wall materials (corn, defatted rice bran, and wheat bran) and different particle sizes (0.6 and 1.0 mm) on the physicochemical characteristics and probiotic encapsulation efficiency. Results revealed that wheat bran, particularly at the smaller particle size of 0.6 mm, enhanced probiotic viability, probiotic stability under simulated gastrointestinal and thermal conditions, and nutrient retention. Compared with other materials, wheat bran also provided superior powder flowability, lower density, and favorable color attributes. In Experiment 2, we assessed the influence of probiotic strains (P. acidilactici, Lactiplantibacillus plantarum TISTR 926, and Streptococcus thermophilus TISTR 894) on functional properties of the DMP. All strains exhibited high encapsulation efficiency and stability during gastrointestinal simulation, thermal exposure, and storage. However, P. acidilactici had superior fermentation kinetics and produced greater levels of beneficial short-chain fatty acids, especially acetic and butyric acids. Antibacterial activity was strain-dependent, with notable inhibitory effects against Gram-positive pathogens, primarily through bacteriostatic mechanisms. Overall, these findings confirm that the developed DMP formulations effectively stabilize probiotics and bioactive phytochemicals, offering a promising strategy for enhancing gut health and performance in antibiotic-free broiler production systems.