Probiotics can also be defined as “Live microorganisms that when administered in adequate amounts confer a health benefit on the host” (Council for Agricultural Science and Technology).

1. Safety and toxicity evaluation of
probiotic foods
Ms. Kiran Verma
Sukhveer Singh
Course Instructor
Dr. P. Prarabdh

2. Health balance of diseased person
Beneficial bacteria
Harmful bacteria

3. N CONTENT
 Introduction
 Scope
 Risk factor
 Toxicity
 Safety
 Evaluation of probiotics
 Conclusion

4. Introduction
• Probiotics can also be defined as “Live microorganisms that when
administered in adequate amounts confer a health benefit on the host”
(Council for Agricultural Science and Technology).
 Most of the commercially available probiotics belong to the
Lactobacillus & Bifidobacterium species, that are part of normal
heathy gastrointestinal mico biota (FAO/WHO,N. Ishibashi, S.
Yamazaki, H.M. Probert et al., Tomasik PJ and Tomasik P).
 Organisms that are regarded as safe along with lactobacilli, are
lactococci, bifidobacterium and yeast.
 There are other probiotic organisms, such as enterococcus, bacillus,
and other spore forming bacteria, as well as streptococci, that are not
generally regarded as safe but have been used as probiotics.
 Here, we will focus on the data regarding the safety of probiotics.

5. Scope
• Assessment of safety must take into account the nature of the microbe
being used, method of administration, level of exposure, health status
of users and physiological functions they are called on to perform.
• The pathogenesis of opportunistic Lactobacillus infections when they
do occur is poorly understood. Since microbes used as probiotics are
non-pathogenic, it is difficult to identify inherent strain properties that
may be related to health risks.
• For instance, the risk of Lactobacillus infection is estimated at about
one case per 10 million people over a century of probiotic
consumption in France (Bernardeau M, et al.)
• However, further investigation is warranted for probiotic use in at-risk
human populations such as severely immune compromised subjects,
neonates or hospitalized patients (Snydamn DR.)

6. Risk factors
The abilities of probiotics to survive and be metabolically active in the
gastrointestinal tract and to interact with the gastrointestinal mucosa and
gastrointestinal microflora have led to 4 areas of concern about safety
(de Vrese M, Schrezenmeir J.).
1. Potential for bacteria to translocate/transmigrate, crossing the barrier
and resulting in invasive infection.
2. The possibility for some probiotic organisms to harbor resistance to
antibiotics, leading to a potential for antibiotic resistance to be
transferred from probiotic bacteria to other potentially pathogenic
bacteria.
3. Metabolic activity and immunologic effects of probiotics leading to
possible deleterious metabolic effects and excessive immune
stimulation (World Health Organization, A.C. Senok, A.Y.
Ismaeel et al.).
4. Finally, products that do not contain the probiotic on the label, or
that contain contaminants may also place the consumer at risk.

7. Characteristics of Probiotics
 Acid tolerance
 Bile tolerance
 Cell surface hydrophobicity
 Protoplast regeneration
 Antimicrobial activity
 Cholesterol removal and bile salt deconjugation
 Gut colonization
 Lactose removal
 Protease and amino peptidase activity

8. Toxicity
 In some cases, pneumonia and endocarditis were reported under the
influence of Lactobacillus bacteria as well as nonsymptomatic fungal
infections caused by Saccharomyces boulardii (Zunic et al., 1991).
 Although most of the species and genera are apparently safe, certain
microorganisms may be problematic, particularly Enterococci (E.
faecium and E. faecalis), which have emerged as opportunistic
pathogens in hospital environments, causing nosocomial infections
such as endocarditis, bacteraemia, and intra-abdominal, urinary tract,
and central nervous system (CNS) infections.
 They may also harbor transmissible antibiotic resistance determinants
(vancomycin-resistant Enterococcus strains) and Bacilli, especially
those belonging to the B. cereus group, which are known to produce
enterotoxins andan emetic toxin (Anadón et al.,2006, 2014).

9.  The potential impact of the use of multidrug resistant probiotics
entering the food chain and disseminating resistance to human or
animal pathogens is always considered. Bacteria may bear transferable
resistance.
 Some enterococcal strains have shown resistance to vancomycin, a
glycopeptide antibiotic with the capacity to transfer this kind of
resistance to other bacterial species.
 Vancomycin is used often for treating patients with infections caused
by Gram-positive microorganisms, particularly nosocomial infections
due to methicillin-resistant Staphylococci.
Cont…

10.  Safety parameters Safety parameters like pathogenicity, infectivity,
toxicity, metabolicactivity and intrinsic properties like antibiotic
resistance are the main criteria for the selection of probiotic organism
(Tripathi & Giri, 2014).
 Lactic acid bacteria and Bifidobacterium are commonly found in
human gut and are GRAS (Anadon et al., 2014).
 Assessment of safety for probiotics is a tedious task (Anadon,
Castellano, & Martínez-Larrañaga, 2014).
 During introduction of new microbes, its genera and strains should be
common in healthy human intestinal microflora, safety and risk-to
benefit ratio are carefully studied and assessed as per CODEX
Alimentarius.
 For novel products it is necessary to perform premarketing
determination of product safety.
Cont…

11.  Lactic acid bacteria and bifidobacteria are the most common bacteria
that attach to the human intestinal mucosa and are commonly regarded
as having the GRAS status.
 Moreover, certain strains of probiotic bacteria have been proven to be
free of risk factors such as transferable antibiotic resistances, cancer-
promoting and/or putrefactive enzymes and metabolites, hemolysis,
activation of thrombocyte aggregation, and mucus degradation in the
mucus layer of the GIT.
 Despite the absence of a pathogenic potential, lactic acid bacteria were
found in <0.1% (enterococci 1%) of clinical samples from severe
infections (endocarditis, meningitis, or bacteremia) (Gasser, 1994).
Safety aspect of probiotics

12.  Members of the genera Lactococcus and Lactobacillus are most
commonly given GRAS status, whereas members of the genera
Streptococcus and Enterococcus and some other genera of lactic
acid bacteria contain some opportunistic pathogens.
 Three approaches can be used to assess the safety of a probiotic
strain:
1. Studies on the intrinsic properties of the strain
2. Studies on the pharmacokinetics of the strain (survival, activity
in the intestine, dose-response relationship, fecal, and mucosal
recovery)
3. Studies searching for interactions between the strain and the
host.
Cont…

13.  It is very important to know the survival of the probiotics within the
GIT, their translocation and colonization properties, and the fate of
their active components to predict the positive effects and/or the side
effects.
 The survival of ingested probiotics at different levels of the GIT differs
between strains (Marteau et al., 1993). Some strains are killed in the
stomach; others (e.g., bifidobacteria or L. acidophilus) can pass
through the entire gut at very high concentrations (Marteau et al.,
1993).
 In Vitro Studies: Estimation of the in vitro infective properties of the
probiotic microorganisms using cell lines and human intestinal mucus
degradation.
Cont…

14.  Animal Studies: the assessment of infectivity can be done in animal
models (e.g., immunocompromised animals or lethally irradiated
animals).
 Noninvasive Tests in Animal Models and Humans: Noninvasive
testing will establish ways to apply dynamic function testing in animal
models and humans to provide reference points to which other
measurements can be related (e.g., altered circulating cytokines,
altered gene expression).
 Studies in Humans: A number of short-term clinical trials on healthy
volunteers attest to the safety of current probiotics.
Cont…

15. Systematic approach for the evaluation of
probiotics in food

16.  Overall probiotic use is safe in most of the cases. However, probiotic
use should be avoided in patients having abnormal gastrointestinal
mucosal barrier, children having short gut syndrome, immuno
compromised patients, patients with central venous catheters.
 we also conclude that there is risk of plasmid mediated transfer of
antibiotic resistance in some probiotic strains.
 The in vitro testing and animal and human studies used for efficacy
and toxicity of probiotics sometimes contain limitations that must be
considered in the assessment.
 In the case of human probiotics, the safety requirements could be more
rigorous, considering that humans with variable health status would
probably use these products as self-medication, and thus a case-by-
case safety approach should be used.
Conclusion

17. Thanks
LET YOUR FOOD BE YOUR MEDICINE AND YOUR MEDICINE BE
YOUR FOOD