The safety of probiotics.

Division of Geographic Medicine and Infectious Diseases and Department of Medicine, Tufts-New England Medical Center, and Tufts University School of Medicine, Boston, Massachusetts 02111, USA.
Clinical Infectious Diseases (Impact Factor: 9.37). 03/2008; 46 Suppl 2:S104-11; discussion S144-51. DOI: 10.1086/523331
Source: PubMed

ABSTRACT Probiotics are generally defined as microorganisms that, when consumed, generally confer a health benefit on humans. There is considerable interest in probiotics for a variety of medical conditions, and millions of people around the world consume probiotics daily for perceived health benefits. Lactobacilli, bifidobacteria, and lactococci have generally been regarded as safe. There are 3 theoretical concerns regarding the safety of probiotics: (1) the occurrence of disease, such as bacteremia or endocarditis; (2) toxic or metabolic effects on the gastrointestinal tract; and (3) the transfer of antibiotic resistance in the gastrointestinal flora. In this review, the evidence for safety of the use of or the study of probiotics is examined. Although there are rare cases of bacteremia or fungemia related to the use of probiotics, epidemiologic evidence suggests no population increase in risk on the basis of usage data. There have been many controlled clinical trials on the use of probiotics that demonstrate safe use. The use of probiotics in clinical trials should be accompanied by the use of a data-safety monitoring board and by knowledge of the antimicrobial susceptibilities of the organism used.

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    ABSTRACT: The safety of two probiotic bifidobacterial strains, Bifidobacterium breve M-16V and Bifidobacterium infantis M-63, was evaluated by single dose and 90-day repeated dose oral toxicity tests using rats. In the single dose oral toxicity test using 1.4 × 10 12 CFU/kg of B. breve M-16V or 3.2 × 10 11 CFU/kg of B. infantis M-63, there were no death and no abnormalities. In the 90-day repeated dose oral toxicity test using 2.3 × 10 11 CFU/kg/day of B. breve M-16V or 7.6 × 10 10 CFU/kg/day of B. infantis M-63, no death and no abnormalities in body weight, food consumption, water consumption, urinalysis, hematology, blood biochemistry, organ weights, and histophathological findings were observed. The acceptable daily intake (ADI) of B. breve M-16V was calculated to be 1.38 × 10 11 CFU/day for an adult weighing 60 kg and 1.15 × 10 10 CFU/day for an infant weighing 5,000 g. Based on the findings of the present study together with the taxonomy and distribution data, as well as clinical experience in preterm infants, B. breve M-16V may be considered as extremely safe for consumption by humans including infants. Although B. infantis M-63 was considered as safe as B. breve M-16V, further confirmation by clinical investigations may be required.
    Bioscience and Microflora. 01/2009; 28(1).
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    ABSTRACT: Probiotics are defined as live microorganisms, which when administered in adequate amounts, confer a health benefit on the host. Health benefits have mainly been demonstrated for specific probiotic strains of the following genera: Lactobacillus, Bifidobacterium, Saccharomyces, Enterococcus, Streptococcus, Pediococcus, Leuconostoc, Bacillus, Escherichia coli. The human microbiota is getting a lot of attention today and research has already demonstrated that alteration of this microbiota may have far-reaching consequences. One of the possible routes for correcting dysbiosis is by consuming probiotics. The credibility of specific health claims of probiotics and their safety must be established through science-based clinical studies. This overview summarizes the most commonly used probiotic microorganisms and their demonstrated health claims. As probiotic properties have been shown to be strain specific, accurate identification of particular strains is also very important. On the other hand, it is also demonstrated that the use of various probiotics for immunocompromised patients or patients with a leaky gut has also yielded infections, sepsis, fungemia, bacteraemia. Although the vast majority of probiotics that are used today are generally regarded as safe and beneficial for healthy individuals, caution in selecting and monitoring of probiotics for patients is needed and complete consideration of risk-benefit ratio before prescribing is recommended.
    International journal of environmental research and public health 01/2014; 11(5):4745-4767. · 1.61 Impact Factor
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    ABSTRACT: Introduction: Kefir is obtained by fermentation of milk with complex microbial populations present in kefir grains. Several health-promoting benefits have been attributed to kefir consumption. Objective: The objective of this work was to conduct a subchronic toxicity study, offering the rats normal or high-doses of kefir and evaluating growth, hematology and blood chemistry, as well as assessing bacterial translocation and the integrity of the intestinal mucosa of animals. Methods: Wistar rats were randomly divided into three groups (n = 6/group): control group received 0.7 mL of water, kefir group received 0.7 mL/day of kefir, (normodose), and Hkefir group received 3.5 mL/day of kefir (fivefold higher dose). Feeding was carried out by gavage. The animals were housed in individual cages and maintained under standard conditions for 4 weeks. Results: The normodose and high-dose of kefir supplementation did not harm the animals since growth, hematology and blood chemistry in rats, as well as the potential pathogenicity in tissues were within normal limits, demonstrating that consumption of normodose and highdose of kefir are safe. In addition, administration of the normodose of kefir reduced cholesterol levels and improved the intestinal mucosa of the rats. Conclusion: These results demonstrate that the consumption of kefir is safe. Importantly, while damages are not seen for the high-dose, the normodose consumption is recommended due to the pronounced beneficial effects, as safety is concerned.
    Nutricion hospitalaria. 01/2014; 29(n06):1352-1359.