Contact us
닫기
Article Search
닫기

Microbiology and Biotechnology Letters

보문(Article)

View PDF

Food Microbiology (FM)  |  Food Borne Pathogens and Food Safety

Microbiol. Biotechnol. Lett. 2021; 49(1): 39-44

https://doi.org/10.48022/mbl.2011.11004

Received: November 18, 2020; Accepted: December 14, 2020

The in vitro and in vivo Safety Evaluation of Lactobacillus acidophilus IDCC 3302

Won Yeong Bang1,2†, Seung A Chae2†, O-Hyun Ban1,2, Sangki Oh2, Chanmi Park2, Minjee Lee2, Minhye Shin3, Jungwoo Yang2*, and Young Hoon Jung1,4*

1School of Food Science and Biotechnology, Kyungpook National University, Daegu 41566, Republic of Korea 2Ildong Bioscience, Pyeongtaek 17957, Republic of Korea 3Department of Agricultural Biotechnology, Research Institute of Agriculture and Life Science, Seoul National University, Seoul 08826, Republic of Korea 4Institute of Fermentation Biotechnology, Kyungpook National University, Daegu 41566, Republic of Korea

Correspondence to :
Jungwoo  Yang,         yjw@ildong.com
Young Hoon  Jung,    younghoonjung@knu.ac.kr

Abstract

Go to

As consumption of healthy foods continues to garner remarkable public attention, ensuring probiotic safety has become a priority. In this study, the safety of Lactobacillus acidophilus IDCC 3302 was assessed in vitro and in vivo. L. acidophilus IDCC 3302 showed negative results for hemolytic and β-glucuronidase activities. The whole-genome analysis (WGA) revealed that L. acidophilus IDCC 3302 did not possess antibiotic resistance or virulence genes. The minimal inhibitory concentrations of L. acidophilus IDCC 3302 confirmed its safety concerning antibiotic resistance. Furthermore, L. acidophilus IDCC 3302 was demonstrated to be nontoxic in the oral toxicity test in rats. Therefore, the results suggested that L. acidophilus IDCC 3302 might be safe for human consumption.

Keywords: Antibiotic resistance, Lactobacillus acidophilus, probiotics, safety evaluation

Introduction

Go to

Probiotics are defined as living microorganisms (i.e., lactic acid bacteria) that benefit human health when ingested appropriately [1, 2]. Lactic acid bacteria (LAB) are found in various habitats, such as humans, plants, and fermented foods [3]. Among the LAB, the Lactobacillus genus has been used as a food additive and starter in the dairy industry [4]. Lactobacillus also produce bacteriocins and exopolysaccharides, which have a protective role in fermented foods and immune-enhancing effects on human health, respectively [5−7]. In particular, Lactobacillus acidophilus, which is often found in human intestines, plays a critical role in enhancing the growth of beneficial LABs and maintaining intestinal flora [8, 9].

L. acidophilus is “generally recognized as safe” because it is non-pathogenic and has a long history of safe use as a probiotic in various food products such as dairy products and fermented meat [10, 11]. However, due to rare but adverse events caused by L. acidophilus, such as diarrhea and bowel irritation [11, 12], the bacteria's safety has been brought into focus [13, 14]. As a result, the FAO/WHO had introduced a guideline for evaluating probiotics as food in 2002. This guideline includes standardized methods for in vivo and in vitro safety assessment.

The characteristics of the commercially available strain, L. acidophilus IDCC 3302, include 66.3% auto-aggregation, 38.0−93.2% co-aggregation with pathogens, 51.2% hydrophobicity, 73.2% acid tolerance, 59.3% bile tolerances, and antipathogenic effects [15]. In this study, L. acidophilus IDCC 3302's antibiotic resistance and toxigenicity were investigated with whole-genome sequence analysis. L. acidophilus IDCC 3302's phenotypes, such as minimal inhibitory concentration, β-hemolysis, extracellular enzyme activity, and the production of biological amines and L/D-lactate, were investigated. Finally, an in vivo, acute oral toxicity (AOT) test was performed to access the bacteria's safety. Therefore, this study is valuable to those who plan to determine the safety of probiotics.

Materials and Methods

Go to

Bacterial strain and culture conditions

L. acidophilus IDCC 3302 (ATCC BAA2845TM), isolated from infant feces, was incubated in MRS (BD Difco, USA) medium at 37℃ in a static incubator under anaerobic condition. As a positive control for hemolytic activity, Staphylococcus aureus (ATCC 25923) was incubated in brain heart infusion (BHI; BD Difco) medium at 37℃ and 200 rpm.

Whole-genome analysis

The whole-genome sequencing of S. thermophilus IDCC 2201 was performed to identify its virulence and antibiotic resistance gene. The VFDB database was searched for virulence genes [16], and ResFider software (ver. 3.2) with the CARD database were searched for antibiotic resistance genes [17]. The search parameters were set to the identity of > 80% and coverage of > 80% for gene identification. Transposases and transferases were annotated using the protein-protein basic local search program (BLASTP) against the NCBI GenBank proteins. Prophage regions were identified using PHASTER web-based program [18].

Antibiotic resistance

L. acidophilus IDCC 3302 was evaluated for its susceptibility to various antibiotics, which are typically used to treat enterococcal infections. Nine antibiotics, ampicillin, vancomycin, gentamicin, kanamycin, streptomycin, erythromycin, clindamycin, tetracycline, and chloramphenicol were used as recommended by EFSA (2018). The test was performed according to CLSI (Clinical Laboratory Standards Institute) protocol. Briefly, a single colony from a plate was inoculated in MRS broth and pre-incubated for 16 h. The cultured cells and antibiotic solution were mixed in a 96-well plate to achieve the initial cell density of 5 × 105 colony-forming unit (CFU)/ml and an antibiotic concentration of 0.125−1024 μg/ml. Then, the plate was incubated at 37℃ anaerobically in a static incubator for 18 h. Finally, the optical density of the cells was measured using a microplate reader (BioTek, USA) to determine the lowest antibiotic concentration that completely inhibited cell growth (minimal inhibitory concentrations, or MICs).

β-Hemolysis activity

Single colonies of L. acidophilus IDCC 3302 and Staphylococcus aureus ATCC 25923, which acted as the positive control, were incubated for 16 h. The incubated cells were streaked on sheep blood agar plates (BBL Microbiology Systems, USA). The plates were then incubated at 37℃ for 24 h. Finally, β-hemolytic activity was indicated by the clear zone that formed around a colony.

Extracellular enzyme activities

Extracellular enzymatic activities were determined using an API-ZYM kit (BIOMÉRIUX, France). Briefly, a single colony of L. acidophilus IDCC 3302 was inoculated and incubated at 37℃ anaerobically for 16 h. The cells were centrifuged, and cell pellets were adjusted to 1.8 × 109 CFU/ml with PBS. The cells were loaded into a 96-well plate and incubated at 37℃ for 4 h. Then, one drop of each of ZYM-A and ZYM-B reagents were added to each well. After 5 min, color changes were observed and compared to the manufacturer's standard response chart.

Biogenic amines production

Biogenic amines (BAs) produced by L. acidophilus IDCC 3302 were analyzed with slight modifications [19]. Five biogenic amines, i.e., tyramine, histamine, putrescine, 2-phenethylamine, and cadaverine, were used as standards as recommended by EFSA [20].

After L. acidophilus IDCC 3302 was cultured in MRS for 16 h, 0.5 ml of supernatant from the culture was mixed with 0.5 ml of 0.1 N HCl. Next, 200 μl of saturated NaHCO3 (Sigma-Aldrich, USA), 20 μl of 2 M NaOH, and 0.5 ml of 10% dansyl chloride (10 mg/ml acetone) were added to the mixture, followed by derivatization at 70℃ for 10 min. Then, 200 μl of L-proline (100 mg/ml H2O) was added into derivatized BAs and incubated in a dark room for 15 min to remove unbound dansyl chloride. Then, acetonitrile (HPLC grade; Sigma-Aldrich) was added to bring the mixturés final volume to 5 ml. Finally, the prepared samples were filtered with a 0.45 μm membrane filter and analyzed using high-performance liquid chromatography (HPLC; LC-NetII/ADC, United Kingdom) equipped with an Athena C18 column (4.6 mm × 250 mm, ANPEL Laboratory Technologies, China). Acetonitrile solution was used as a mobile phase with a constant flow rate of 0.8 ml/min. The BAs were detected by a UV detector (UV-2075 plus, Jasco), and BAs concentrations were determined according to the calibrated curve.

Determination of L/D-lactate concentrations

The L-/D-lactate production of L. acidophilus IDCC 3302 was determined using the L-/D-lactate enzyme test kit (Megazyme, Ireland). Briefly, 0.1 ml of the supernatant of L. acidophilus IDCC 3302 culture was mixed with 1.5 ml of H2O, 0.5 ml of supplied buffer (pH 10.0), 0.1 ml of NAD+ solution, and 0.02 ml of glutamatepyruvate transaminase (GPT) and incubated at room temperature for 3 min. Then, the absorbance of D-lactate was measured at 340 nm. Next, 0.02 ml of 2,000 U/ml lactate dehydrogenase (LD) was added to the above reaction mixture, and the absorbance of D-lactate was measured for 3 min until the LD reaction stopped. Then, the absorbance of L-lactate was measured at 340 nm. The concentrations of L-/D-lactate were calculated according to the equations according to the manufacturer's instruction.

Acute oral toxicity (AOT) test in rats

Acute oral toxicity (AOT) test was performed by the Korea Testing & Research Institute (KTR; Korea) according to the Ministry of Food and Drug Safety and OECD guidelines [21]. Briefly, twelve Crl:CD(SD) female rats aged 9 to 10 weeks were divided into four groups of three rats each. Each group was orally administrated with 300 or 2000 mg of L. acidophilus IDCC 3302 powder in 10 ml sterilized water. The rats' viability, general symptoms, and body weight changes were monitored for 14 days. Finally, 100-ml isoflurane injections were used to euthanize the rats, autopsied, and visually inspect for organ abnormalities.

The animal experiments in this study were conducted by Korea Testing and Research Institute (KTR) under Animal protection act (no. 14651) and laboratory animal act (no. 15278) by Korea government.

Results and Discussion

Go to

Antibiotic resistance and whole-genome analysis

L. acidophilus IDCC 3302 was susceptible to all of the antibiotics with MIC values at or below the EFSA cutoff values, except for kanamycin (Table 1). The wholegenome analysis revealed that L. acidophilus IDCC 3302 did not have any gene similar to antibioticresistant genes (Table S1 and Fig. S1). Thus, the resistance to kanamycin was regarded as an intrinsic trait of this strain. Many Lactobacillus species are relatively tolerant of aminoglycoside antibiotics, i.e., kanamycin [10, 22], likely due to the reduced uptake of aminoglycosides in the absence of cytochrome-mediated transport [23, 24]. For example, 79% out of 187 isolates from 55 European probiotics products showed kanamycin resistance [25]. Meanwhile, a kanamycin cutoff value was suggested as more than 256 mg/l for all Lactobacillus species based on MIC values of 37 strains [6]. Additionally, L. acidophilus IDCC 3302 was evaluated for genome sequence similarities to known virulence factors using the VFDB database [16]; it does not carryany toxigenic gene. In conclusion, L. acidophilus IDCC 3302 was regarded as safe concerning antibiotic resistance according to genomic evaluation and MIC values tested in this study.

Table 1 . L. acidophilus IDCC 3302's minimum inhibitory concentrations (MIC) against a variety of antibiotics.

AMPVANGENKANSTRERYCLITETCHL
Cutoff value (μg/ml)121664161444
L. acidophilus IDCC 33020.5/S20.5-1/S4-16/S128/R34/S<0.125/S1-2/S0.25/S2-4/S

1EFSA (European Food Safety Authority), 2018. EFSA Journal, 16(3), 5206.

2S: susceptible, 3R: resistant.

Abbreviations: AMP, ampicillin; CHL, chloramphenicol; CLI, clindamycin; ERY, erythromycin; GEN, gentamicin; KAN, kanamycin; STR, streptomycin; TET, tetracycline; VAN, vancomycin.

β-Hemolytic activity

Hemolysis caused by a bacterial infection, such as invasion, frequently triggers hemolytic symptoms, including anemia, fever, and skin rash [26]. Thus, it is essential to evaluate the hemolytic activity of probiotics to ensure their safety. In this study, L. acidophilus IDCC 3302 produced no clear or greenish zone surrounding the colonies, showing γ-hemolytic (non-hemolytic) (Fig. S2).

Extracellular enzyme activities

The extracellular enzymatic profile of L. acidophilus IDCC 3302 was investigated using the API ZYM kit (Fig. S3). As probiotics, lactic acid bacteria should not produce β-glucuronidase, which indicates the formation of potentially carcinogenic compounds, such as cycasin, and toxic steroids, such as estrogen [27]. As expected, β- glucuronidase activity was absent in L. acidophilus IDCC 3302 (Table 2). On the other hand, the presence of β-glucosidase and β-galactosidase may be advantageous for human health (Table 2). For example, β-glucosidase hydrolyzes glucose conjugates from various foods to generate beneficial secondary metabolites in the colon [28]. β-galactosidase, which converts lactose into glucose and galactose, is reported to reduce lactose intolerance [29]. Meanwhile, another strain, such as L. acidophilus MVA3, was reported to have neither β-glucosidase nor β-galactosidase [30].

Table 2 . Enzymatic activities of L. acidophilus IDCC 3302 using the API-ZYM kit.

EnzymeL. acidophilus IDCC 3302
Alkaline phosphate-
Esterase+
Esterase lipase-
Lipase-
Leucine arylamidase+
Valine arylamidase+
Cystine arylamidase-
Trypsin-
α-Chymotrypsin-
Acid phosphatase+
Naphthol-AS-BI-phosphohydrolase+
α-Galactosidase-
β-Galactosidase+
β-Glucuronidase-
α-Glucosidase+
β-Glucosidase+
N-acetyl-β-glucosaminidase-
α-Mannosidase-
α-Fucosidase-


Biogenic amines production

Biogenic amines (BAs) derive from the decarboxylation of amino acids; they can cause toxic effects in humans, such as headache, vomiting, and diarrhea [31]. Typically, lactic acid bacteria are considered the primary producers of BAs in fermented foods. Thus, many studies have been focused on the safety of BA accumulation by lactic acid bacteria [32]. Here, L. acidophilus IDCC 3302 could not produce tyramine, histamine, putrescine, 2-phenethylamine, or cadaverine (data not shown). Among the BAs examined, tyramine and histamine are considered the most important in food safety because they are responsible for scombroid fish poisoning, and food-induced migraine [33]. Some Lactobacillus strains, such as L. sakei, L. plantarum, L. casei, L. paracasei, and L. reuteri, were reported to produce tyramine or histamine or both [32]. In conclusion, L. acidophilus IDCC 3302 is determined to be safe concerning biogenic amine production due to its lack of biogenic amine production.

Determination of the ratio of D- to L-lactate

The bacteria of the Lactobacillus genus can produce lactate from the fermentation of carbohydrates. Lactate exists in two forms, L-lactate, the levorotary enantiomer, and D-lactate, the dextrorotary enantiomer [34, 35]. Because humans do not metabolize D-lactate, its production and accumulation by intestinal microflora might trigger D-lactate acidosis and short bowel syndrome [36]. However, there is no research on the amount of D-lactate produced by intestinal microflora or whether it may trigger symptoms in humans. Although D-lactate concentration of patients with the symptoms is comparatively higher, the risk of D-lactate in healthy humans is extremely low [37]. In this study, quantification of lactate produced by L. acidophilus IDCC 3302 indicated an approximate 1:4 ratio of D- to L-lactate (6.95 ± 0.06 mg/ml of D-lactate and 23.54 ± 0.19 mg/ml of L-lactate) (Table 3). Compared to other Lactobacillus strains, the proportion of D-lactate produced by L. acidophilus IDCC 3302 is relatively low. In comparison, L. reuteri NCIMB 3053 had a 6:5 of D-/L-form ratio, L. delbrueckii ATCC 11842 had 12:11, L. rhamnosus GG ATCC 53103 had 3:13 [38].

Table 3 . The production of L-/D-lactic acid isomers by L. acidophilus IDCC 3302.

StrainsL-lactic acid (mg/ml)D-lactic acid (mg/ml)Ratio of isomers (%)
L-formD-form
L. acidophilus IDCC 330223.54 ± 0.196.95 ± 0.0677.2022.80


Acute oral toxicity in rats

A single-dose acute oral toxicity test was performed in rats to evaluate the L. acidophilus' safety in vivo. A 14-day observation revealed that a single oral dose of 7.9 × 109 −5.3 × 1010 CFU/g of L. acidophilus IDCC 3302 did not cause death or toxicity in 9 to 10-week old rats. Also, there were no significant changes in the micés appearance, such as skin, hair, behavior, weight, and feed intake (Table 4). No significant pathological change was found in any rat during the autopsy. Thus, there was no evidence of any toxicity in rats receiving L. acidophilus IDCC 3302.

Table 4 . The body weight changes of the female rats administered with L. acidophilus IDCC 3302 at different dosages.

GroupDosage (g/kg BW1)Body weight (g)2
Day 0Day 1Day 3Day 7Day 14
9 week-aged300217.1 ± 3.2241.7 ± 4.3246.2 ± 10.1254.0 ± 15.1267.4 ± 6.9
2000235.4 ± 12.0260.6 ± 13.8263.3 ± 5.5277.6 ± 15.9282.3 ± 12.9
10 week-aged300208.4 ± 15.7223.4 ± 19.1229.8 ± 17.8237.7 ± 22.6245.6 ± 21.7
2000215.6 ± 10.8234.4 ± 15.8242.2 ± 10.5245.4 ± 10.3259.0 ± 13.2

1BW, body weight

2Values are mean ± SD of 3 replicates

In conclusion, the safety of L. acidophilus IDCC 3302 isolated from infant feces was assessed with in vitro and in vivo tests. The whole-genome analysis and MIC tests showed this strain to be safe in terms of antibiotic resistance. The analysis of the potential toxins produced by L. acidophilus IDCC 3302 showed that the strain had an extremely low probability of producing toxic compounds. Furthermore, there was no evidence of L. acidophilus IDCC 3302 having any toxicity in rats. Therefore, we concluded that L. acidophilus IDCC 3302 is safe as probiotics for human consumption.

Acknowledgment

Go to

This work was supported by Ildong Bioscience, Co., Ltd., and the National Research Foundation of Korea (NRF) grant funded by Korea government (Ministry of Science and ICT, MSIT) [grant number 2020R1C1C1005251].

Conflict of Interest

Go to

The authors have no financial conflicts of interest to declare.

References

Go to
  1. Chandan RC. 1999. Enhancing market value of milk by adding cultures. J. Dairy Sci. 82: 2245-2256.
    CrossRef
  2. Gill H, Prasad J. 2008. Probiotics, immunomodulation, and health benefits. Adv. Exp. Med. Biol. 606: 423-454.
    Pubmed CrossRef
  3. Françoise L. 2010. Occurrence and role of lactic acid bacteria in seafood products. Food Microbiol. 27: 698-709.
    Pubmed CrossRef
  4. Chamba JF, Irlinger F. 2004. Secondary and adjunct cultures. pp. 191-206. In Patrick FF, Paul LHM, Timothy MC, Timothy PG (eds.),: chemistry.
    CrossRef
  5. Alander M, Satokari R, Korpela R, Saxelin M, Vilpponen-Salmela T, Mattila-Sandholm T, et al. 1999. Persistence of colonization of human colonic mucosa by a probiotic strain, Lactobacillus rhamnosus GG, after oral consumption. Appl. Environ. Microbiol. 65: 351-354.
    Pubmed KoreaMed CrossRef
  6. Danielsen M, Wind A. 2003. Susceptibility of Lactobacillus spp. to antimicrobial agents. Int. J. Food Microbiol. 82: 1-11.
    CrossRef
  7. Kirjavainen PV, Ouwehand AC, Isolauri E, Salminen SJ. 1998. The ability of probiotic bacteria to bind to human intestinal mucus. FEMS Microbiol. Lett. 167: 185-189.
    Pubmed CrossRef
  8. Kos BVZE, Šušković J, Vuković S, Šimpraga M, Frece J, Matošić S. 2003. Adhesion and aggregation ability of probiotic strain Lactobacillus acidophilus M92. J. Appl. Microbiol. 94: 981-987.
    Pubmed CrossRef
  9. Tannock GW. 1999. Probiotics: a critical review. J. Antimicrob. Chemother. 43: 849.
    CrossRef
  10. Abriouel H, Casado Muñoz MC, Lerma LL, Montoro BP, Bokelmann W, Pichner R, et al. 2015. New insights in antibiotic resistance of Lactobacillus species from fermented foods. Food Res. Int. 78: 465-481.
    Pubmed CrossRef
  11. Donohue DC, Salminen S. 1996. Safety of probiotic bacteria. Asia pacific J. Clin. Nutr. 5: 25-28.
  12. Saxelin M, Rautelin H, Salminen S, Mäkelä PH. 1996. Safety of commercial products with viable Lactobacillus strains. Infect. Dis. Clin. Pract. 5: 331-335.
    CrossRef
  13. Antony SJ. 2000. Lactobacillemia: an emerging cause of infection in both the immunocompromised and the immunocompetent host. J. Natl. Med. Assoc. 92: 83-86.
  14. Schlegel L, Lemerle S, Geslin P. 1998. Lactobacillus species as opportunistic pathogens in immunocompromised patients. Eur. J. Clin. Microbiol. Infect. Dis. 17: 887-888.
    Pubmed CrossRef
  15. Vijayalakshmi S, Adeyemi DE, Choi IY, Sultan G, Madar IH, Park MK. 2020. Comprehensive in silico analysis of lactic acid bacteria for the selection of desirable probiotics. LWT 130: 109617.
    CrossRef
  16. Chen L, Yang J, Yu J, Yao Z, Sun L, Shen Y, et al. 2005. VFDB: a reference database for bacterial virulence factors. Nucl. Acids Res. 33: D325-D328.
    Pubmed KoreaMed CrossRef
  17. Zankari E, Hasman H, Cosentino S, Vestergaard M, Rasmussen S, Lund O, et al. 2012. Identification of acquired antimicrobial resistance genes. J. Antimicrob. Chemother. 67: 2640-2644.
    Pubmed KoreaMed CrossRef
  18. Arndt D, Grant JR, Marcu A, Sajed T, Pon A, Liang Y, et al. 2016. PHASTER: a better, faster version of the PHAST phage search tool. Nucl. Acids Res. 44: W16-W21.
    Pubmed KoreaMed CrossRef
  19. Priyadarshani WM, Rakshit SK. 2011. Screening selected strains of probiotic lactic acid bacteria for their ability to produce biogenic amines (histamine and tyramine). Int. J. Food Sci. Technol. 46: 2062-2069.
    CrossRef
  20. Rychen G, Aquilina G, Azimonti G, Bampidis V, Bastos MDL, et al, EFSA Panel on Additives, Products or Substances used in Animal Feed (FEEDAP). 2018. Guidance on the characterisation of microorganisms used as feed additives or as production organisms. EFSA J. 16: e05206.
    Pubmed CrossRef
  21. OECD.
  22. Ammor MS, Flórez AB, Mayo B. 2007. Antibiotic resistance in nonenterococcal lactic acid bacteria and bifidobacteria. Food Microbiol. 24: 559-570.
    Pubmed CrossRef
  23. Charteris WP, Kelly PM, Morelli L, Collins JK. 2001. Gradient diffusion antibiotic susceptibility testing of potentially probiotic lactobacilli. J. Food Prot. 64: 2007-2014.
    Pubmed CrossRef
  24. Mayrhofer S, Van Hoek AHAM, Mair C, Huys G, Aarts HJ, Kneifel W, et al. 2010. Antibiotic susceptibility of members of the Lactobacillus acidophilus group using broth microdilution and molecular identification of their resistance determinants. Int. J. Food Microbiol. 144: 81-87.
    Pubmed CrossRef
  25. Temmerman R, Pot B, Huys G, Swings J. 2003. Identification and antibiotic susceptibility of bacterial isolates from probiotic products. Int. J. Food Microbiol. 81: 1-10.
    CrossRef
  26. Kodner C, Kudrimoti A. 2003. Diagnosis and management of acute interstitial nephritis. Am. Fam. Physician 67: 2527-2534.
  27. Kim DH, Jin YH. 2001. Intestinal bacterial β-glucuronidase activity of patients with colon cancer. Arch. Pharm. Res. 24: 564-567.
    Pubmed CrossRef
  28. Choi YB, Kim KS, Rhee JS. 2002. Hydrolysis of soybean isoflavone glucosides by lactic acid bacteria. Biotechnol. Lett. 24: 2113-2116.
    CrossRef
  29. Delgado S, O' Sullivan E, Fitzgerald G, Mayo B. 2008. In vitro evaluation of the probiotic properties of human intestinal Bifidobacterium species and selection of new probiotic candidates. J. Appl. Microbiol. 104: 1119-1127.
    Pubmed CrossRef
  30. Colombo M, Castilho NP, Todorov SD, Nero LA. 2018. Beneficial properties of lactic acid bacteria naturally present in dairy production. BMC Microbiol. 18: 219.
    Pubmed KoreaMed CrossRef
  31. Spano G, Russo P, Lonvaud-Funel A, Lucas P, Alexandre H, Grandvalet C, et al. 2010. Biogenic amines in fermented foods. Eur. J. Clin. Nutr. 64: S95-S100.
    Pubmed CrossRef
  32. Barbieri F, Montanari C, Gardini F, Tabanelli G. 2019. Biogenic amine production by lactic acid bacteria: a review. Foods 8: 17.
    Pubmed KoreaMed CrossRef
  33. Ladero V, Calles-Enríquez M, Fernández M, Alvarez MA. 2010. Toxicological effects of dietary biogenic amines. Curr. Nutr. Food Sci. 6: 145-156.
    CrossRef
  34. Sanders ME, Akkermans LM, Haller D, Hammerman C, Heimbach JT, Hörmannsperger G. 2010. Safety assessment of probiotics for human use. Gut Microbes 1: 164-185.
    Pubmed KoreaMed CrossRef
  35. Uribarri J, Oh MS, Carroll HJ. 1998. D-lactic acidosis: a review of clinical presentation, biochemical features, and pathophysiologic mechanism. Medicine 77: 73-82.
    Pubmed CrossRef
  36. Møller PD, Diernaes L, Sehested J, Hyldgaard-Jensen J, Skadhauge E. 1997. Absorption and fate of L-and D-lactic acid in ruminants. Physiol. A Physiol. 118: 387-388.
    CrossRef
  37. Quigley EM, Pot B, Sanders ME. 2018. 'Brain Fogginess' and DLactic acidosis: probiotics are not the cause. Clin. Transl. Gastroenterol. 9: 187.
    Pubmed KoreaMed CrossRef
  38. Sulemankhil I, Parent M, Jones ML, Feng Z, Labbé A, Prakash S. 2012. In vitro and in vivo characterization and strain safety of Lactobacillus reuteri NCIMB 30253 for probiotic applications. Can. J. Microbiol. 58: 776-787.
    Pubmed CrossRef

Article Tools

Starts of Metrics

Share this article on :

Related articles in MBL

Most Searched Keywords ?

What is Most Searched Keywords?

  • It is most registrated keyword in articles at this journal during for 2 years.