Probiotics are live microorganisms that confer health benefits onto the host when administered at adequate doses. Most widely used probiotics, such as lactobacilli and bifidobacteria, are known to be elements of healthy gut microflora and hence are not considered a threat to the host. However, probiotics may pose a risk in certain populations with compromised immune systems or defects in gut barrier functions. Herein, we evaluated the safety of Bifidobacterium breve BB077, according to the safety evaluation guidelines for probiotics produced by the National Institute of Food and Drug Safety Evaluation (NIFDS). The results show that B. breve BB077 is both non-hemolytic and non-cytolytic. In contrast, B. breve BB077 exhibited higher streptomycin and tetracycline resistance than the suggested NIFDS standard cut-off values. Hence, a genetic analysis of the streptomycin and tetracycline resistance genes was performed to determine the origin of antimicrobial resistance. Streptomycin and tetracycline resistance was shown have arisen from chromosomal mutations and considered intrinsic to the taxonomic group. In conclusion, the B. breve BB077 strain might be safe for human consumption.

ABSTRACT
Materials and Methods
    사용 균주
    용혈활성 확인
    세포독소 생성 확인
    항생제 내성
    항생제 내성 유전자 분석
Results and Discussion
    용혈활성 확인
    세포독소 확인
    항생제 내성
국문요약
Conflict of interests
ORCID
References

• 우장빈((주)씨에이치랩스) | Jang-Bin Woo (CH Labs Corp., Chong Kun Dang Health care Labs, Seoul, Korea)
• 한지윤((주)씨에이치랩스) | Ji Yoon Han (CH Labs Corp., Chong Kun Dang Health care Labs, Seoul, Korea)
• 서은솔((주)씨에이치랩스, 서울대학교 농업생명과학대학 바이오모듈레이션학과) | Eunsol Seo (CH Labs Corp., Chong Kun Dang Health care Labs, Seoul, Korea/WCU Biomodulation Major, Department of Agricultural Biotechnology, College of Agriculture and Life Sciences, Seoul National University, Seoul, Korea)
• 서민영(㈜신우코퍼레이션) | MinYeong Seo (ShinWoo Co., Ltd, Anyang-si, Korea)
• 김병용((주)씨에이치랩스) | Byung-Yong Kim (CH Labs Corp., Chong Kun Dang Health care Labs, Seoul, Korea) Corresponding author