Safety assessment of Lactobacillus reuteri IDCC 3701 based on phenotypic and genomic analysis

Abstract

Purpose Lactobacillus reuteri is one of the most largely studied human-commensal bacteria and widely used as a form of probiotics. Safety of probiotics has become increasingly important for human consumption due to increasing health-concerns in food industry. In this study, the safety of L. reuteri IDCC 3701 isolated from human breast milk was thoroughly investigated. Methods Whole-genome sequence analysis was performed to identify antibiotic resistance and toxigenicity of L. reuteri IDCC 3701. Phenotypic analysis such as minimal inhibitory concentration, β-hemolysis, extracellular enzyme activity, and the production of biological amines and L/D-lactate, was investigated. Finally, acute oral toxicity test was performed to access L. reuteri IDCC 3701 safety. Results Although multiple resistances to gentamicin and kanamycin were observed in L. reuteri IDCC 3701, it was revealed that these resistances are intrinsic and not transferable through whole-genome analysis. In addition, various phenotypic analysis concerning hemolysis, enzyme activity, and D-lactate production did not show any negative results. Although L. reuteri IDCC 3701 harbors a histidine decarboxylase gene, no biogenic amines were detected. Finally, L. reuteri IDCC 3701 exhibited no evidence of acute toxicity according to an in vivo study. Conclusion Our findings demonstrate that L. reuteri IDCC 3701 is considered to be safe for human consumption as probiotics based on the in silico, in vitro and in vivo studies.

Potential of Bifidobacteriumlactis IDCC 4301 isolated from breast milk‐fed infant feces as a probiotic and functional ingredient

“…BL produced more l ‐lactate than d ‐lactate: 17.37 mg/mL of l ‐lactate (82.87%) and 3.59 mg/mL of d ‐lactate (17.13%). The value of d ‐lactate formation and the ratio of d ‐ to l ‐lactate were much lower than those of other lactic acid bacteria such as L. plantarum , L. acidophilus , L. reuteri , and L. delbrueckii (Bang et al, 2021 ; Lee et al, 2021 ; Sulemankhil et al, 2012 ). In particular, L. reuteri NCIMB 30253 and L. delbrueckii ATCC 11842 produced higher ratios of d ‐lactate than l ‐lactate, with 6:5 and 12:11 ratios of d ‐ to l ‐lactate, respectively (Sulemankhil et al, 2012 ).…”

Probiotic Characteristics and Safety Assessment of Lacticaseibacillus casei KGC1201 Isolated from Panax ginseng

“…Noxious enzymes, such as β-glucuronidase, have the capacity to convert procarcinogens to carcinogens through hydrolysis of glycosidic bonds [ 36 ]. The accumulation of D-lactate can occur only in case of gastrointestinal dysfunction, such as D-lactate metabolism disorders, but excessive accumulation of D-lactate in the blood can cause health problems [ 37 ]. Hemolytic activity, usually caused by hemolysin produced by microorganisms, induces lysis of red blood cells leading to infection by pathogens [ 38 ].…”

Anti-Inflammatory Effects of Limosilactobacillus fermentum KGC1601 Isolated from Panax ginseng and Its Probiotic Characteristics

“…Thus, the resistance against kanamycin and streptomycin seems to be an intrinsic trait of this strain. Indeed, several studies have shown that several Lactobacillus species, including some commercially used strains, exhibit relative resistance to aminoglycoside antibiotics, such as gentamicin, kanamycin, and streptomycin [ 17 , 23 , 24 ]. As a result, L. fermentum KGC1601 can be considered safe in terms of antibiotic resistance.…”