In the antibiotics-free era, stimbiotic (STB) has been suggested as a new alternative of antibiotic growth promoters to modulate intestinal health via stimulating dietary fiber utilization in poultry production. The aim of this study was to evaluate the effects of STB supplementation in corn- or wheat-basal diet on growth performance, intestinal development, and function of broilers. A total of 512 one-day-old Arbor Acres(AA)broilers were randomly allocated 4 treatments, including corn group (CG), corn + 100 g/t STB (CG + STB), wheat group (WG), wheat + 100 g/t STB (WG + STB). The broilers were weighed at the days of 14, 28, and 42, of which 8 repetitions per treatment were randomly selected to determine the intestinal morphology, intestinal barrier, and cecal microbiota and metabolites. Our data showed that STB increased (P < 0.05) feed intake, body weight and reduced FCR for the overall period (0-42 d). At 28 d of age, significant increases in villus height and the villus height-to-crypt depth ratio (V/C) were found in the STB supplementation groups (P < 0.05). Addition of STB significantly increased intestinal mucosal DAO and AMPK enzyme activity and the gene expression of OCLN, CLDN1, ZO1, MUC2, SGLT1, PEPT1, FABP2, Ghrelin, and GCG in jejunum (P < 0.05), and significantly decreased the expression of the PYY gene. In addition, STB increased the relative abundance of beneficial bacteria, such as Akkermansia, Bifidobacterium, and Oscillospirales (P < 0.05). A significant increase in cecal short-chain fatty acid (SCFAs) concentration was also observed in the STB supplementation groups. At the cellular level, STB cannot directly increase the expression of small intestinal epithelial cells, and may indirectly improve intestinal barrier function by increasing the level of sodium butyrate. Overall, these results indicated that STB supplementation could improve the growth performance, intestinal development and barrier functions, and fiber fermentation in cecum of broiler chickens.

The intestinal structure and function of laying hens undergo age-related degeneration, which can impair nutrient absorption and reduce production performance. Chinese herbal additives have been investigated for their potential benefits in supporting intestinal health and physiological function. In this study, a compound seven-herb formula was evaluated for its potential to support intestinal health in late-phase laying hens. The study aimed to compare the effects of unfermented and fermented herbal formulations on laying performance, egg quality, and intestinal health in late-phase laying hens. A total of 540 hens were randomly assigned to three groups (six replicates per group, 30 hens per replicate) and fed either a basal diet (Control), a diet supplemented with Chinese herbal medicine (CHM), or a diet supplemented with fermented Chinese herbal medicine (FHM) for 12 consecutive weeks. During weeks 9–12, egg production rate was significantly higher in the CHM and FHM groups than in the control group (p < 0.05). Over the entire experimental period, average egg weight was significantly higher in the FHM group than in the control and CHM groups (p < 0.05). Both treatments also improved selected indices of intestinal morphology, including villus height and the villus height-to-crypt depth ratio (p < 0.05). Additionally, serum concentrations of immunoglobulin A (IgA), the immunoglobulin reported as IgG, and immunoglobulin M (IgM) were significantly increased, whereas intestinal concentrations of interleukin-1β (IL-1β), interleukin-8 (IL-8), and transforming growth factor-β (TGF-β) were reduced in both treatment groups (p < 0.05). Both CHM and FHM supplementation reduced serum malondialdehyde (MDA) concentrations and increased superoxide dismutase (SOD) activity, although serum glutathione peroxidase (GSH-Px) activity was decreased (p < 0.05). Furthermore, FHM altered the cecal microbial composition and increased the concentrations of acetate, butyrate, and isovalerate. In conclusion, dietary herbal supplementation, particularly in fermented form, may improve selected production-performance traits and intestinal health in aged laying hens.