ID 2974 -
Streptococcus thermophilus P 18807
PL: Streptococcus thermophilus P 18807
EN: Streptococcus thermophilus P 18807
Pdf:
1. Charakterystyka żywności / składnika
Introduction on the process used for characterisation of food constituents that are bacteria and yeasts:
Correct identification of the bacterium's and yeast's species and strain is of critical importance, as the observed effects in the host are species and strain specific.
The appropriate classification, identification and nomenclature of microorganisms constitute the starting point for the assessment of microbial properties. Classification assigns a microorganism to a known taxonomic group according to its similarity to that group. This classification allows the prediction of the general properties of the microorganism on the basis of what is already known about the taxon. A reliable identification confirms the identity of the strain(s) used in a given process and requires the use of appropriate methods.
Bacteria - Traditional phenotypic identification of bacteria is not always reliable as certain species cannot be distinguished by these methods. Molecular techniques have emerged as a replacement or complement to traditional phenotypic tests in recent years. DNA-DNA hybridisation has become the generally accepted standard for determination of bacterial species identification. Phylogenetic approaches based on sequence analysis of the 16S rRNA gene have also proven to be a useful tool for bacterial identification. The EU-funded PROSAFE project concluded that biochemical tests should not be used as a stand-alone approach for identification of bacterial cultures (Vankerckhoven et al., 2008b). The use of 16S rRNA gene sequence analysis was considered the best tool for routine species identification. Moreover, the use of sequence-based methods, such as 16S rRNA gene sequencing, was encouraged given their high reproducibility and data exchangeability (Vankerckhoven et al., 2008a). The FAO/WHO expert group (FAO/WHO, 2006) recommends that phenotypic tests should be done first, followed by genetic identification, using methods such as DNA-DNA hybridisation or 16S rRNA gene sequence analysis. Nevertheless, it is important to underline that in some cases 16S rRNA gene sequencing has a limited resolution and it may not be enough for discriminating closely related species (Felis and Dellaglio, 2007; Vankerckhoven et al., 2008a) making it necessary to use other methods.
For the strain identification (characterisation of the strain by genetic typing), the FAO/WHO working group also recommended that strain typing has to be performed with a reproducible genetic method. DNA macrorestriction followed by Pulsed Field Gel Electrophoresis (PFGE) is considered as the generally accepted standard (FAO/WHO, 2006) and it has been extensively used for differentiating
4 Regulation (EC) No 1924/2006 of the European Parliament and of the Council of 20 December 2006 on nutrition and health claims made on foods. OJ L 404, 30.12.2006, p. 9–25.
Non-characterised bacteria and yeasts related health claims
EFSA Journal 2010; 8(2):1470 8
commercial microorganism strains. Other discriminatory molecular methods, such as Randomly Amplified Polymorphic DNA (RAPD) among others, are also available for strain characterisation.
Yeasts - Traditional phenotypic characterisation of yeasts is not always reliable for species and strain identification. Currently, the available molecular techniques complement and replace traditional phenotypic tests for this purpose, because they have higher discrimination power and are independent of growth conditions. Strains of the species Saccharomyces cerevisiae are widely distributed in nature and used for different food fermentation processes (wine, beer, cider, bread, etc.) (Moreno-Arribas et al., 2005; Coton et al., 2006; Legras et al., 2007). This species can also be a saprophytic coloniser of human mucosal surfaces and has been isolated from the digestive tract, vagina, skin and oropharynx of healthy individuals (Aucott et al., 1990). Although the taxonomic designation of Saccharomyces cerevisiae var boulardii to the species Saccharomyces cerevisiae is controversial, currently the former is not accepted as a distinct species (Mitterdorfer et al., 2002).
Some of the most useful molecular methods to identify yeasts are based on the spacer regions between the highly conserved rRNA genes (rDNA). The spacer regions between the rDNA subunits (internal transcribed spacer; ITS) and between the repeats (non-transcribed spacer; NTS) are highly variable between and within species, which allows their use for taxonomy purposes with different discrimination power (Baleiras Couto et al., 1996). One of the widely accepted techniques used for the adscription of yeasts to the species Saccharomyces cerevisiae is the restriction fragment length polymorphisms (RFLP) analysis of the PCR products of the 5.8S-ITS region (Mitterdorfer et al., 2002; De Llanos et al., 2004, 2006). Other alternative molecular techniques used for identification of yeast species is the sequence analysis of the D1 and D2 domains of 26S rDNA (Kurtzman and Robnett, 1998; Coton et al., 2006) and rDNA spacer regions (Posteraro et al., 2005).
For identification of strains, diverse molecular typing techniques are available, including chromosome length polymorphism analysis by PFGE, RAPD, and microsatellite DNA polymorphism analysis (Mitterdorfer et al., 2002; van der Aa Kühle et al., 2005; Posteraro et al., 2005).
Hence, species identification and sufficient characterisation (genetic typing) at strain level of the bacteria/yeasts by using internationally accepted molecular methods is needed. In addition, strains should be named according to the International Code of Nomenclature.
Although there is no direct requirement on deposition of the particular strain in an internationally recognised culture collection, the FAO/WHO (FAO/WHO, 2006) recommends that strains should also be deposited in an internationally recognised culture collection (with access number). These will assure the tracking and access of scientists and regulatory authorities to the strain and related information in case it is needed.
In the context of the Regulation (EC) No 1924/2006, the purposes of characterisation are to confirm the identity of the food/constituent that is the subject of the health claim, and to establish that the studies provided for substantiation of the health claim were performed with the food/constituent in respect of which the health claim is made. Although not required for substantiation of a claim, characterisation should also be sufficient to allow control authorities to verify that the food/constituent which bears a health claim is the same one that was the subject of a community authorisation.
The Panel has decided to use the following criteria for characterisation of food constituents that are bacteria, which are the subject of health claims:
Species identification by DNA-DNA hybridisation or 16S rRNA gene sequence analysis.
Strain identification by DNA macrorestriction followed by PFGE, RAPD, or other internationally accepted genetic typing molecular methods.
Non-characterised bacteria and yeasts related health claims
EFSA Journal 2010; 8(2):1470 9
Only when these two criteria were fulfilled, the bacterium was considered to be sufficiently characterised.
The Panel has decided to use the following criteria for characterisation of food constituents that are yeasts, which are the subject of health claims:
Species identification of by restriction fragment length polymorphism analysis (RFLP) (e.g. RFLP of PCR products the 5.8S rDNA internal transcribe spacer [ITS] region) or by sequencing analysis of DNA taxonomic markers (e.g. the D1 and D2 domains of 26S rDNA or ITS regions).
Strains identification by chromosome length polymorphism (PFGE), RAPDs, microsatellite DNA polymorphism analysis or other internationally accepted genetic typing molecular techniques.
Only when these two criteria were fulfilled, the yeast was considered to be sufficiently characterised.
In the case of combination of several bacteria and/or yeasts, the Panel considers that if one microorganism used in the combination is not sufficiently characterised, the combination proposed is not sufficiently characterised.
The characterisation of food constituents that are bacteria and yeasts, which are the subject of health claims pursuant to Article 13 of the Regulation (EC) No 1924/2006, is based on evaluation of available references up to 31 December 2008, including the following:
The information provided by the Member States in the consolidated list of Article 13 health claims and references that EFSA has received from Member States or directly from stakeholders;
Generally available data obtained by searching PubMed and Web of Science databases by using the strain name as search term.
1.15. Characterisation of “Streptococcus thermophilus P18807” (ID 2974, 2975)
The food constituent that is the subject of the health claim is Streptococcus thermophilus P18807. According to the patent application by Dondi (2008), the strain is deposited in the LMG under nº LMG P-18807. In the LMG, which is a non-public International Depositary Authority under the Budapest Treaty, cultures can also be deposited in a restricted-access collection as Patent deposits.
Reference to phenotypic identification of the strain (sugar fermentation and SDS-PAGE profiles) was found in the references provided (Dondi, 2008; BCCM/LMG, 1999). No other information regarding the identification/characterisation of the strain was found in the literature. The Panel considers that Streptococcus thermophilus P18807, which is the subject of the health claims ID 2974 and 2975, is not sufficiently characterised.
2.1. Zmniejszenie dolegliwości ze strony przewodu pokarmowego (ID 2946, 2951, 2974)
The claimed effect, which is proposed for further assessment, is: “Is a probiotic; Contributes to a healthy digestive system by supporting the gut flora through an increased number of positive lactobacillus in the intestine; useful to maintain a healthy intestinal flora by adhering to the mucosa; Improves intestinal barrier function by competing (steric encumbrance) against pathogens; Reduces gastro-intestinal discomfort; Necessary to maintain a healthy digestive system by production of specific enzymes (e.g.: beta-galactosidase)”. The proposed target population is the general population.
The Panel considers that reduction of gastro-intestinal discomfort is a beneficial physiological effect.
2.2. Zmniejszenie ilości potencjalnie patogennych mikroorganizmów przewodu pokarmowego (ID 2946, 2951, 2974)
The claimed effect, which is proposed for further assessment, is: “Is a probiotic; Contributes to a healthy digestive system by supporting the gut flora through an increased number of positive lactobacillus in the intestine; useful to maintain a healthy intestinal flora by adhering to the mucosa; Improves intestinal barrier function by competing (steric encumbrance) against pathogens; Reduces gastro-intestinal discomfort; Necessary to maintain a healthy digestive system by production of specific enzymes (e.g.: beta-galactosidase)”. The proposed target population is the general population.
The Panel notes that it is not possible to define the exact number of the different microbial groups which constitute a normal microbiota. Increasing the number of any groups of microorganisms, including lactobacilli, is not in itself considered to be a beneficial physiological effect.
The Panel assumes that the claimed effect refers to a decrease in potentially pathogenic gastro-intestinal microorganisms. The Panel considers that decreasing potentially pathogenic gastro-intestinal microorganisms might be a beneficial physiological effect.
2.3. Poprawa trawienia laktozy (ID 2946, 2951, 2974)
The claimed effect, which is proposed for further assessment, is: “Is a probiotic; Contributes to a healthy digestive system by supporting the gut flora through an increased number of positive lactobacillus in the intestine; useful to maintain a healthy intestinal flora by adhering to the mucosa; Improves intestinal barrier function by competing (steric encumbrance) against pathogens; Reduces gastro-intestinal discomfort; Necessary to maintain a healthy digestive system by production of specific enzymes (e.g.: beta-galactosidase)”. The proposed target population is the general population.
The Panel assumes that the claimed effect refers to improved lactose digestion and that the target population is individuals with lactose maldigestion. Lactose maldigestion is a common condition caused by reduced levels of intestinal lactase.
The Panel considers that improved lactose digestion is a beneficial physiological effect for individuals with lactose maldigestion.
3.1. Zmniejszenie dolegliwości ze strony przewodu pokarmowego (ID 2946, 2951, 2974)
Most of the references provided were on L. acidophilus strains other than the one which is part of the combination of microorganisms (Bernet et al., 1994), and on methodologies for bacterial strain identification (Giraffa et al., 1998; Jensen et al., 1993; Miteva et al., 2001; Moschetti et al., 1998; Ventura et al., 2000). A patent on methods for selection of Lactobacillus strains with ability to adhere to human mucosa (Dondi, 2000), by which the strains that are the subject of the claim were isolated, and a human intervention study on the viability of yogurt bacteria (e.g. L. delbrueckii subsp. bulgaricus and S. thermophilus) through the human intestinal tract (Elli et al., 2006) were also provided. The Panel notes that these studies did not address effects of the combination of strains that is the subject of the claim, notes that these studies did not address outcome measures related to the claimed effect, and considers that no conclusions can be drawn from these studies for the scientific substantiation of the claim.
The Panel concludes that a cause and effect relationship has not been established between the consumption of a combination of L. acidophilus BCCM/LMG P-18806, L. delbrueckii BCCM/LMG P-18805 and S. thermophilus BCCM/LMG P-18807 and reduction of gastro-intestinal discomfort.
3.2. Zmniejszenie ilości potencjalnie patogennych mikroorganizmów przewodu pokarmowego (ID 2946, 2951, 2974)
Most of the references provided were on L. acidophilus strains other than the one which is part of the combination of microorganisms (Bernet et al., 1994), and on methodologies for bacterial strain identification (Giraffa et al., 1998; Jensen et al., 1993; Miteva et al., 2001; Moschetti et al., 1998; Ventura et al., 2000). A patent on methods for selection of Lactobacillus strains with ability to adhere to human mucosa (Dondi, 2000), by which the strains that are the subject of the claim were isolated,
was also provided. In the patent it was only indicated how the mucosa-adhesion ability of the lactic acid bacterial strains and pathogens was measured. A human intervention study on the viability of yogurt bacteria (e.g. L. delbrueckii subsp. bulgaricus and S. thermophilus) through the human intestinal tract (Elli et al., 2006) was also provided. The Panel notes that these studies did not address effects of the combination of strains that is the subject of the claim, notes that they did not address outcome measures related to the claimed effect, and considers that no conclusions can be drawn from these studies for the scientific substantiation of the claim.
The Panel concludes that a cause and effect relationship has not been established between the consumption of a combination of L. acidophilus BCCM/LMG P-18806, L. delbrueckii BCCM/LMG P-18805 and S. thermophilus BCCM/LMG P-18807 and decreasing potentially pathogenic gastro- intestinal microorganisms.
3.3. Poprawa trawienia laktozy (ID 2946, 2951, 2974)
Most of the references provided were on L. acidophilus strains other than the one which is part of the combination of microorganisms (Bernet et al., 1994), and on methodologies for bacterial strain identification (Giraffa et al., 1998; Jensen et al., 1993; Miteva et al., 2001; Moschetti et al., 1998; Ventura et al., 2000). A patent on methods for selection of lactobacilli strains with ability to adhere to human mucosa (Dondi, 2000), by which the strains that are the subject of the claim were isolated and a human intervention study on the viability of yogurt bacteria (i.e. L. delbrueckii subsp. bulgaricus and S. thermophilus) through the human intestinal tract (Elli et al., 2006) were also provided. The Panel notes that these studies did not address effects of the combination of strains that is the subject of the claim, notes that they did not address outcome measures related to the claimed effect, and considers that no conclusions can be drawn from these studies for the scientific substantiation of the claim.
The Panel concludes that a cause and effect relationship has not been established between the consumption of a combination of L. acidophilus BCCM/LMG P-18806, L. delbrueckii BCCM/LMG P-18805 and S. thermophilus BCCM/LMG P-18807 and improved lactose digestion.
Warunki i możliwe ograniczenia stosowania oświadczenia
Almeno 4 x 109 ufc/die
