Microencapsulated sodium butyrate (MS-SB) is an effective sodium butyrate additive which can reduce the release of sodium butyrate (SB) in the fore gastrointestinal tract. In this study, we assess the protective effects and mechanisms of MS-SB in Clostridium perfringens (C. perfringens)-challenged broilers. Broiler chickens were pre-treated with SB or MS-SB for 56 days and then challenged with C. perfringens three times. Our results indicate that the addition of MS-SB or SB before C. perfringens infection significantly decreased the thymus index (p < 0.05). Serum IgA, IgY, and IgM concentrations were significantly increased (p < 0.05), while pro-inflammatory IL-1β, IL-6, and TNF-α were significantly decreased (p < 0.05) under MS-SB or SB supplementation. Compared with SB, MS-SB presented a stronger performance, with higher IgA content, as well as a lower IL-1β level when normal or C. perfringens-challenged. While C. perfringens challenge significantly decreased the villus height (p < 0.05), MS-SB or SB administration significantly increased the villus height and villus height/crypt depth (V/C ratio) (p < 0.05). Varying degrees of SB or MS-SB increased the concentrations of volatile fatty acids (VFAs) during C. perfringens challenge, where MS-SB presented a stronger performance, as evidenced by the higher content of isovaleric acid and valeric acid. Microbial analysis demonstrated that both SB or MS-SB addition and C. perfringens infection increase variation in the microbiota community. The results also indicate that the proportions of Bacteroides, Faecalibacterium, Clostridia, Ruminococcaceae, Alistipes, and Clostridia were significantly higher in the MS-SB addition group while, at same time, C. perfringens infection increased the abundance of Bacteroides and Alistipes. In summary, dietary supplementation with SB or MS-SB improves the immune status and morphology of intestinal villi, increases the production of VFAs, and modulates cecal microbiota in chickens challenged with C. perfringens. Moreover, MS-SB was more effective than SB with the same supplemental amount.

The aim of the present study was to investigate the effects of Bacillus licheniformis (BL) on the growth performance, antioxidant capacity, ileal morphology, intestinal fecal short-chain fatty acids, and microflora of weaned piglets challenged with lipopolysaccharide (LPS). Piglets were assigned into three groups: basal diet (Con), a basal diet with added 10⁹ CFU B. licheniformis/kg (BLl), and a basal diet with added 10¹⁰ CFU B. licheniformis/kg (BLh). On day 28, BLh piglets were intraperitoneally injected with LPS (CBL) and sterilized saline water (BL), Con piglets were injected with LPS (LPS) and sterilized saline water (Con), with the injections being administered for three consecutive days. The average daily gain significantly increased from day 1 to day 28 and the feed: gain ratio decreased with BL supplementation compared with the Con group. Supplementation with BLl and BLh reduced the diarrhea rate in piglets. Serum catalase activity increased and malondialdehyde concentration decreased in the CBL treatment group compared with the LPS treatment group. Both BL and CBL treatments increased the ileal villus length/crypt depth ratio compared with Con and LPS treatments. BL administration significantly increased colonic propionic and isobutyric acid concentrations compared with Con treatment. Both BL and CBL piglets had significantly increased fecal acetic, propionic, and butyric acid levels compared with LPS piglets. Analysis of the colonic microbial metagenome showed that Prevotella species were the predominant bacteria in piglets treated with BL and CBL. The CBL-treated piglets had higher scores for lysine biosynthesis, arginine biosynthesis, sulfur relay system, and histidine metabolism. BL-treated piglets had higher scores for glycosaminoglycan biosynthesis-keratan sulfate, oxidative phosphorylation, and pyruvate and carbon metabolism.