The purpose of this study was to investigate probiotic characteristics and immune enhancing effects of Bifidobacterium (B.) longum KBB1-26 and BIF-4, B. breve KBB5-22 isolated from human intestine for probiotic use in humans and animals. We measured acid, bile and heat tolerance, antimicrobial activity against pathogenic bacteria, Escherichia (E.) coli, Salmonella (S.) Enteritidis, Staphylococcus (S.) aureus, and Listeria (L.) monocytogenes. Immune enhancing effects of B. longum and B. breve were investigated by measuring nitric oxide (NO), nuclear factor (NF–κb), interleukin-1ß (IL-1ß), interleukin-6 (IL-6), interleukin-12 (IL-12) and tumor necrosis factor- α (TNF- α) in RAW 264.7 cells or RAW BLUE cells. B. longum KBB1-26 was survived at pH 2.0. B. longum KBB1-26 and BIF-4, B. breve KBB5-22 also showed tolerance to 0.3% of oxgall bile salt. B. longum KBB1-26 was able to survive at 70 ℃ and 80 ℃ for 20 min. KBB1-26 showed the antimicrobial inhibition zone to pathogenic bacteria such as E. coli (12 mm), S. Enteritidis (14 mm), S. aureus (14 mm) and L. monocytogenes (41 mm). The production of NO (4.5 ± 0.00μM/mL) and IL-1β (39.7 ± 0.55pg/mL) of KBB1-26 significantly higher than BIF-4 and KBB5-22, respectively. In addition, KBB1-26 and KBB5-22 induce the production of high level of TNF-α and IL-6 in macrophages. Collectively, B. longum KBB1-26 have acid, bile, heat tolerance, antimicrobial activity and immune enhancing effects. These results suggest that KBB1-26 can be used as probiotics for humans and animals.

Introduction
 Materials and Methods
  공시 유산균
  내산성 및 내담즙성 검사
  내열성 검사
  병원균 억제능 검사
  Heat-killed 유산균 준비
  세포배양
  NO 측정
  NF-κB 측정
  Cytokine 측정
  통계분석 및 유의성 검정
 Results
  내산성 및 내담즙성 결과
  내열성 확인 결과
  병원균 억제능
  NO 및 NF-Κb 활성 확인
  Cytokine 생성능 확인
 Discussion
 References

• Ho-Eun Park(Laboratory of Bacteriology College of Veterinary Medicine Chungbuk National University)
• Hyun-Bum Um(Laboratory of Bacteriology College of Veterinary Medicine Chungbuk National University)
• Wan-Kyu Lee(Laboratory of Bacteriology College of Veterinary Medicine Chungbuk National University) Corresponding author