Four hundred and fifty 1-d-old male Lingnan Yellow broiler chickens were used to investigate the effects of Clostridium butyricum on growth performance, immune function, and cecal microflora. The birds were randomly assigned to 5 treatments and offered the same antibiotic-free basal diets for 42 d. The treatments were as follows: no addition (control), 1 × 10(7) cfu C. butyricum/kg of diet (CB1), 2 × 10(7) cfu C. butyricum/kg of diet (CB2), 3 × 10(7) cfu C. butyricum/kg of diet (CB3), and 10 mg of colistine sulfate/kg of diet (antibiotic). Birds fed either CB2 or antibiotic had greater overall BW than those in the control group. During d 1 to 7, d 21 to 42, and d 1 to 42, birds fed either CB2 or CB3 or the antibiotic diet had greater ADG compared with those in the control group. No significant differences were observed in BW or ADG among the CB2, CB3, and antibiotic groups. Birds fed the CB2 or CB3 diet had greater concentrations of IgA and IgG in the serum from d 14 to 42 and greater IgM in the serum from d 21 to 42 than those in the control group. Birds fed the CB3 diet had a greater concentration of complement component 3 in the serum than those in the control group from d 7 to 42. Dietary C. butyricum decreased (P < 0.05) Escherichia coli in cecal contents on d 14 and 42, and both CB2 and CB3 decreased (P < 0.05) cecal Salmonella and Clostridium perfringen from d 14 to 42 compared with the control. Broilers fed either CB2 or CB3 had greater cecal Lactobacillus and Bifidobacterium counts from d 21 to 42, and birds fed C. butyricum had greater cecal C. butyricum counts during the whole period compared with those in the control group. The results indicate that C. butyricum promotes growth performance and immune function and benefits the balance of the intestinal microflora in broiler chickens.

The effects of feeding dehydrated Enterococcus faecium on growth performance, immune response, and cecal microflora in broiler chickens challenged with Escherichia coli K88 were investigated. Two hundred eighty-eight 1-d-old birds were randomly assigned to 4 treatments: negative control birds (N-con) fed a basal diet and not challenged with E. coli K88; positive control birds (P-con) fed a basal diet and challenged with E. coli K88; birds fed a basal diet including dehydrated E. faecium (Ef) at 1 × 10(9) cfu/kg of feed and challenged with E. coli K88; and birds fed a basal diet including the antibiotic colistine sulfate (Anti) at 10 mg/kg of feed and challenged with E. coli K88. Birds fed E. faecium had greater (P < 0.05) BW on d 14, 21, and 28 and greater (P < 0.05) jejunal villus height on d 21 and 28 compared with birds on the other treatments. Jejunal crypt depth was decreased (P < 0.05) in birds fed either E. faecium or antibiotic compared with P-con treatment birds on d 10, 21, and 28. Birds fed E. faecium had a greater (P < 0.05) concentration of IL-4 in their jejunal mucosa than did those in the N-con treatment group on d 10, 14, and 21. Infected birds, with or without E. faecium feeding, had a higher (P < 0.05) tumor necrosis factor-α and secreted IgA in their jejunal mucosa than did those in the N-con treatment group on d 10 and 14. Birds fed E. faecium had lower (P < 0.05) concentrations of E. coli on d 14 and 28, less (P < 0.05) Clostridium perfringens on d 28, greater Lactobacillus counts on d 14 and 21, and greater (P < 0.05) Bifidobacterium in their cecal contents on d 21 than did the P-con birds. These results suggest that E. faecium can promote growth performance, improve intestinal morphology, and beneficially manipulate the cecal microflora in broilers challenged with E. coli K88.

Aims:  To characterize the antimicrobial and adhesion ability of candidate probiotic Clostridium butyricum CB2 for farmed fish in vitro. Methods and Results:  The potential probiotic Cl. butyricum CB2 had been evaluated for its adhesion capacity and antagonistic effect against two fish pathogens Aeromonas hydrophila and Vibrio anguillarum by the intestinal cell model. In addition, the aggregation ability and antimicrobial property on agar plate were assayed. The results indicated that the candidate probiotic Cl. butyricum CB2 have strong adhesion property and a higher antagonistic activity to Aer. hydrophila and V. anguillarum both on agar plate and cell model. Clostridium butyricum showed a higher aggregation which might be the reasons for bacteria adhesion and antimicrobial activity. Conclusions:  The strain Cl. butyricum CB2 could be used as potential probiotic to inhibit pathogens growth and prevent their colonization in fish intestinal tract. Significance and Impact of the Study:  This study revealed the antimicrobial and adhesion characteristic of Cl. butyricum CB2 which was selected as the potential probiotic to farmed fish.

This study was conducted to investigate the effects of Clostridium butyricumon growth performance, immune function, and cecal microflora in broiler chickens challenged with Escherichia coli K88. Three hundred sixty 1-d-old broiler chickens were randomly divided into 4 treatments: negative control (NC) birds were fed a basal diet and not challenged with E. coli K88; positive control (PC) birds were fed a basal diet and challenged with E. coli K88; C. butyricum treatment (CB) birds were fed a diet containing 2 × 10(7) cfu C. butyricum/kg of diet and challenged with E. coli K88; and colistin sulfate treatment (CS) birds were fed a diet containing 20 mg of colistin sulfate/kg of diet and challenged with E. coli K88. Birds fed CB had greater (P < 0.05) BW than the PC birds from 3 to 21 d postchallenge. Birds fed CB had greater (P < 0.05) serum IgA and IgY at 14 d postchallenge, greater (P < 0.05) serum IgM at 21 d postchallenge, and greater (P < 0.05) mucosal secreted IgA at 3 and 7 d postchallenge than the PC birds. Birds fed CB had greater concentrations of serum complement component 3 at 14 d postchallenge, and greater (P < 0.05) concentrations of serum complement component 4 at 3, 7, and 14 d postchallenge than the PC birds. Birds in the CS or CB treatments had less cecal E. coli population at 3, 7, and 21 d postchallenge, and less cecal Clostridium perfringens counts at 21 d postchallenge compared with the PC birds. The CB treatment increased (P < 0.05) the population of cecal Lactobacillus at 3 d postchallenge and the number of cecal Bifidobacterium at 3, 14, and 21 d postchallenge in comparison with the PC treatment. The results indicate that dietary supplementation of CB promotes growth performance, improves immune function, and benefits the cecal microflora in Escherichia coli K88-challenged chickens.