Effects of Bacillus licheniformis on growth performance, immune and antioxidant functions, and intestinal microbiota of broilers.

Bacillus licheniformis (BL) has been widely regarded as an important growth promoter in recent years. However, its usage in animal industry still needs more foundations. The aim of our study was to study the effects of BL on the growth performance, immunity, oxidative function and intestinal flora of broilers. A total of 760 one-day-old yellow-feathered broilers were randomly divided into 4 groups with 10 replicates per group and 19 broilers per replicate. The broilers in the control group (CON) were fed with basal diet. The treatment groups were supplemented with 250 mg/kg (BL250), 500 mg/kg (BL500) and 750 mg/kg (BL750) BL in the basal diet for 70 d. Results showed that BL groups significantly increased the body weight (BW) and average daily gain (ADG), decreased average daily feed intake (ADFI) and feed conversion ratio (FCR). In addition, the spleen and bursa indexes were higher in the BL groups than that in the CON group at d 70. BL supplementation also markedly increased the levels of immunoglobulins Y (IgY), IgA and anti-inflammatory interleukin 10 (IL-10), reduced the levels of proinflammatory IL-1ß, tumor necrosis factor α (TNF-α) and IL-2 in the serum at 70 d in a concentration-dependent manner. Besides, BL addition significantly increased the levels of series antioxidant enzymes including total antioxidant capacity (T-AOC), glutathione peroxidase (GPX), superoxide dismutase (SOD), and catalase (CAT), and decreased the level of malondialdehyde (MDA) in the serum. Moreover, BL groups showed an obvious increase of isobutyric acid markedly and BL500 group significantly promoted the level of isovaleric acid in cecal contents of broilers. Finally, microbial analysis showed that BL supplementation presented visual separations of microbial composition and increased the relative abundance of p_Proteobacteria, g_Elusimicrobium, and g_Parasutterella comparing with the CON group. Together, this study inferred that dietary BL supplementation improved the growth performance, immune and antioxidant functions, changed the intestinal microflora structure and metabolites of yellow-feathered broilers, which laid a good basis for the application of probiotics in the future.

Protective effects of Bacillus licheniformis on growth performance, gut barrier functions, immunity and serum metabolome in lipopolysaccharide-challenged weaned piglets.

Bacillus licheniformis (B. licheniformis) is a well-accepted probiotic that has many benefits on both humans and animals. This study explored the effects of B. licheniformis on growth performance, intestinal mucosal barrier functions, immunity as well as serum metabolome in the weaned piglets exposed to lipopolysaccharide (LPS). One hundred and twenty piglets weaned at four weeks of age were separated into two groups that received a basal diet (the control group, CON), and a basal diet complemented with B. licheniformis (500 mg/kg, the BL group, BL). Twenty-four piglets were chosen from the above two groups and 12 piglets were injected with LPS intraperitoneally at a concentration of 100 µg/kg and the others were injected with sterile saline solution of the same volume. All the piglets were sacrificed 4 h after LPS challenge. Results showed that B. licheniformis enhanced the ADG and final body weight and lowered the F/G and diarrhea rate. Pre-treatment with B. licheniformis markedly attenuated intestinal mucosal damage induced by LPS challenge. Supplementation with B. licheniformis strengthened immune function and suppressed inflammatory response by elevating the concentrations of serum immunoglobulin (Ig) A and jejunum mucosal IgA and IgG and decreasing serum IL-6 and jejunum mucosal IL-1ß. In addition, B. licheniformis pretreatment prevented LPS-induced intestinal injury by regulating the NLRP3 inflammasome. Furthermore, pretreatment with B. licheniformis tended to reverse the reduction of acetate and propionic acids in the colonic contents that occurred due to LPS stress. B. licheniformis markedly modulated the metabolites of saccharopine and allantoin from lysine and purine metabolic pathways, respectively. Overall, these data emphasize the potentiality of B. licheniformis as a dietary supplement to overcome the challenge of bacterial LPS in the animal and to enhance the food safety.

Effects of Glyceryl Monolaurate on Production Performance, Egg Quality, Oviduct Cytokines and Intestinal Microflora of 66 Weeks Old Laying Hens.

The principal purpose of this research was to study the effects of glycerol monolaurate (GML) on the production performance; egg quality; health state of the oviduct, ovary and ileum; and gut microbiota of laying hens in the later stage. The laying hens were randomly assigned to two groups: a control group and an experiment group, for which 1000 mg/kg of GML was added to a control diet. The results showed that GML increased the laying rate, average egg weight, albumen height, yolk color and Haugh unit and decreased the feed conversion ratio and defective eggs (p < 0.05). GML increased the intestinal villi height and the ratio of villus height to crypt depth (p < 0.05). Moreover, GML improved the contents of cytokines in the oviduct, ovary and ileum mucosa; ameliorated the expression of TLR2, TLR4, MyD88, IL-4, IL-1ß and TNF-α; and increased the expression of Occludin and Muc-2 in the ileal mucosa. The supplementation of GML increased the volatile fatty acids in the cecal contents, such as acetic acid and propionic acid, and up-regulated Bacteroides (p < 0.01) and Alistipes (p < 0.05) richness in the cecal contents. In summary, GML improved production performance, egg quality and immunity; ameliorated the health status of the oviduct, ovary and ileum; enhanced the intestinal barrier function; improved the content of intestinal volatile fatty acids; and regulated the abundance of cecal flora.

Effects of Bacillus licheniformis on Growth Performance, Diarrhea Incidence, Antioxidant Capacity, Immune Function, and Fecal Microflora in Weaned Piglets.

Bacillus licheniformis (B. licheniformis) is a safe probiotic that can promote animal growth and inhibit pathogenic bacteria. This study aimed to assess the effects of B. licheniformis, one green feed additive, on growth performance, diarrhea incidence, immune function, fecal volatile fatty acids, and microflora structure in weaned piglets. Weaned piglets (n = 180) were randomly divided into three treatment groups and fed a basal diet and a basal diet supplemented with 500 mg B. licheniformis per kg and 1000 mg B. licheniformis per kg, respectively. The dietary 500 mg/kg B. licheniformis inclusion improved the average daily gain, reduced diarrhea incidence, and strengthened antioxidant capacity. Piglets supplemented with B. licheniformis presented increased serum immunoglobulins (IgA, IgM) compared to the CON group. Meanwhile, the expression of anti-inflammation factors was increased, and the levels of pro-inflammation factors were reduced after B. licheniformis administration. Moreover, the levels of volatile fatty acids, including acetic acid, propionic acid, butyric acid, isobutyric acid, and isovaleric acid, in the BL500 and BL1000 groups were increased compared with the CON group, and the concentration of valeric acid was higher in the BL500 group. Furthermore, piglets in the 500 mg/kg B. licheniformis addition group significantly altered fecal microbiota by increasing Clostridium_sensu_stricto_1 and Oscillospira. In conclusion, dietary B. licheniformis relieved diarrhea, enhanced antioxidant capacity, immunity function, and fecal microflora structure in weaned pigs.

Effects of dietary glyceryl monolaurate supplementation on growth performance, non-specific immunity, antioxidant status and intestinal microflora of Chinese mitten crabs.

This study aims to investigate the effects of glycerol monolaurate (GML) on growth performance, non-specific immunity, antioxidant capacity and intestinal microflora in Chinese mitten crabs. The crabs were randomly arranged to three experimental diets groups containing 0 (control group), 1000 mg/kg GML (GML1000 group), and 2000 mg/kg GML (GML2000 group), respectively. After 8 weeks of breeding, results showed a better growth performance in GML2000 group, with a higher PWG, SGR and lower FCR (P < 0.05). Meanwhile, in GML2000 group the activities of phenoloxidase, alkaline phosphatase, acid phosphatase and lysozyme in hemolymph were increased (P < 0.05), also the activities of hemolymph and hepatopancreas superoxide dismutase (SOD) and glutathione peroxidase (GPx) were increased in hepatopancreas (P < 0.05). While malondialdehyde (MDA) concentrations were lower significantly (P < 0.05) both in GML1000 and GML2000 groups. Furthermore, the mRNA expression of TLR1, TLR2, which related to the Toll pathway were increased (P < 0.05). Supplementation of 2000 mg/kg GML up-regulated the expression of ALF and LZM (P < 0.05), and down-regulated the expression of caspase-3 (P < 0.05). The abundance of Firmicutes increased in GML2000 group (P < 0.05), and Shewanella was significantly increased (P < 0.05) in both GML1000 and GML2000 groups. In conclusion, dietary supplemented with GML enhanced the growth performance and antioxidant capacity, enhanced hemolymph immune enzymes activities and antimicrobial peptides expression through regulating the proPO system and Toll pathway, and improved gut microflora in Chinese mitten crabs.

Inulin and isomalto-oligosaccharide alleviate constipation and improve reproductive performance by modulating motility-related hormones, short-chain fatty acids, and feces microflora in pregnant sows.

Constipation in gestating and lactating sows is common and the inclusion of dietary fiber may help to alleviate this problem. We investigated the effects of inulin (INU) and isomalto-oligosaccharide (IMO), two sources of soluble dietary fiber, on gastrointestinal motility-related hormones, short-chain fatty acids (SCFA), fecal microflora, and reproductive performance in pregnant sows. On day 64 of gestation, 30 sows were randomly divided into three groups and fed as follows: a basal diet, a basal diet with 0.5% INU, and a basal diet with 0.5% IMO. We found that INU and IMO significantly modulated the levels of gastrointestinal motility-related hormones, as evidenced by an increase in substance P (P < 0.05), and a decrease in the vasoactive intestinal peptide concentrations (P < 0.05), indicating the capacity of INU and IMO to alleviate constipation. Furthermore, IMO enhanced the concentrations of acetic, propionic, isobutyric, butyric, isovaleric, and valeric acids in the feces (P < 0.05). High-throughput sequencing showed that IMO and INU increased the fecal microflora α- and ß-diversity (P < 0.05). Methanobrevibacter was more abundant (P < 0.05), whereas the richness of Turicibacter was lower in the INU and IMO groups than in the control group (P < 0.05). In addition, IMO significantly increased litter size (P < 0.05). Overall, our findings indicate that INU and IMO can relieve constipation, optimize intestinal flora, and promote reproductive performance in pregnant sows.