Edition 2/96
Edition 2/96 |
PROBIOTICS ADDITIVES |
In general, the probiotic effect is exerted via action in the gastrointestinal tract but beneficial effects have also been reported in the urogenital tract as well.
Bacteria claimed to have probiotic effects are mainly assigned to the lactic acid group and to the genus Bifidobacterium. However, numerous reports link beneficial health effects to species of other Gram positives (e.g. Propionibacterium, Bacillus), Gram negatives (e.g. Escherichia coli), yeasts (e.g. Candida, Saccharomyces) and fungi (e.g. Aspergillus).
The use of probiotics is most widespread in commercial animal feed products and feed additives. However, probiotic-like yoghurts and other fermented dairy products have been making an impact on the human food market for a number of years. Most of these products claim to have one or more beneficial health effects, such as:
Whereas the use of probiotics in animal feeds is regulated by a European Commission Directive (see ‘Regulations’ below), the present European legislation does not yet cover their use in food products for human consumption. National legislation differs from country to country.
Clearly, the safety of probiotic products manufactured and distributed on a wide scale depends on the correct identification of the micro-organism(s) involved and on the stability of a number of factors directly and indirectly linked to claimed health benefits. The BCCM™/LMG collection’s professional identification services offer a number of interesting possibilities for the identification, characterization and safe deposit of probiotic strains (see below).
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(1) Lilly and Stillwell, 1965; Science 147, 747-748
(2) Parker, 1974; Anim. Nutr. Health 29, 4-8
(3) Fuller, 1989; J. Appl.Bacteriol. 66, 365-378
Guidelines for the identification, characterization and evaluation of probiotic feed additives are set forward in Council Directive 87/153/EEC, modified by the Commission Directives 94/40/EC and 95/11/EC.
One of these guidelines states: "It is necessary to deposit reference material [microbiological strains used in animal feed] in a culture collection that is recognized as an International Depositary Authority (IDA), in accordance with the Budapest Treaty [Budapest, 28 April, 1977; amended 26 September, 1980] in order to have guarantee on the conservation without any change of the microbial strains and consequently of continuity during the industrial use."
Furthermore it is stated that, in all cases, "a copy of the receipt of deposit of the micro-organism with an IDA should be provided, precising the name and the taxonomic description of the micro-organism according to the International Code of Nomenclature".
The BCCM™ consortium has been recognized as an IDA by the World Intellectual Property Organization (WIPO) since 1992. By depositing bacterial/fungal cultures at one of the relevant BCCM™ collections, all the requirements of the EU Directives are automatically satisfied. Deposited strains can be analyzed taxonomically and entered in a closed BCCM™ collection as a ‘safe deposit’, implying that the culture is not published in any BCCM™ catalogue or on-line information network and that subcultures are only made available for the depositor or an authorized mandatary.
Copies of the Commission’s directives and amendments are available from the BCCM™ upon request.
Contact: Anne Depauw,
BCCM™ Co-ordination Team
E-mail: depa@belspo.be
Tel: +32 2 238 34 62
Fax: +32 2 230 59 12
Professor Dellaglio is professor of general and industrial microbiology at the Universita Degli Studi Di Verona in Italy, where his research interests focus on basic and applied research into lactic acid bacteria, propionibacteria and other bacteria related to food. His work brings him into regular contact with the BCCM™/LMG collection in Belgium.
"The collection offers excellent identification and taxonomic facilities," explains Professor Dellaglio. "A member of my research team spent several weeks at BCCM™/LMG working on the genetic identification and characterization of propionibacteria. We have over 80 strains stored there now."
Professor Dellaglio relies on the BCCM™/LMG to provide him with reliable cultures both of the strains deposited there by his research team and others from the collection’s extensive catalogue. "Because the BCCM™/LMG provides information not only on the strain but also on its source and other references I find that I can select a sample with greater confidence," he says. "This translates to repeatable results in the lab - very important to my research."
The professor is in no doubt that probiotics will prove to be instrumental in protecting against human intestinal disorders through antimicrobial, biochemical and physiological mechanisms. Nevertheless, he is aware that there is currently considerable disagreement on the methodology and efficacy used in the study of probiotic effects. "Opinion ranges from very optimistic to guarded," he says. Professor Dellaglio believes that scientists could improve their credibility in a number of ways, including:
Professor Dellaglio advocates the eventual combination of probiotics and prebiotics once the necessary research on symbiotics has been completed. "Since prebiotics stimulate the growth of a host’s own beneficial bacteria, I think that they are more easily accepted by consumers," he adds.
The increased use of prebiotics, probiotics and symbiotics should help to reduce the use of antibiotics, which is especially important in the light of growing antimicrobial resistance(1).
But what form will consumer probiotics take? Professor Dellaglio believes that fresh food products - particularly fermented milk products - are the way forward. "But this means that probiotic strains will need to be selected not only for their health-promoting effects but also according to their influence on the texture, aroma and acidity of the product," he points out.
Professor Dellaglio feels that EU legislation for human probiotics is needed, as is the case for animal feed. He believes that genetically modified probiotic micro-organisms may offer even greater benefits but that they must be rigorously tested for safety according to stringent EU protocols.
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(1) See BCCM™ News 1
BCCM™/LMG recently contributed to Probiotics ’96 meeting entitled "Probiotics in man and animal", organized by the Deutsche Veterinärmedizinische Gesellschaft (DVG), the Deutsche Gesellschaft für Hygiene und Mikrobiologie (DGHM) and the Bundesinstitut für gesundheitlichen Verbraucherschutz und Veterinärmedizin (BgVV).
The meeting was held on 20-22 June in the historical Harnack House in Berlin, Germany. We would like to thank Prof. G. Reuter, Prof. J. Krämer, Prof. P. Teufel and Dr. G. Klein for inviting BCCM™/LMG to this interesting symposium which covered:
A round table discussion was held on the ‘genetic stability’ of Gram positive bacteria, which is becoming increasingly important to a number of issues, including the emergence of antibiotic resistance(1).
BCCM™/LMG made a presentation on "The taxonomy of micro-organisms used as probiotics with special focus on enterococci, lactococci and lactobacilli". The reliability of the identification of lactic acid bacteria by SDS-PAGE of whole-cell proteins was demonstrated by comparison to other traditional, time consuming, genotypic methods. Moreover, the results of a recent comparative study of typing methods were presented: AFLP™, REP-PCR, ERIC-PCR, RAPD analysis and PFGE of rare-cutted restriction fragments revealed different groupings of strains when applied on a selection of Enterococcus faecium strains. An evaluation of the resulting patterns by numerical analysis was shown to be possible; results largely improved by applying more primers and / or restriction enzymes.
Besides the proceedings made available at the conference, full contributions will be published in one of the next issues of Microecology and Therapy.
The decision to organize a second Probiotics meeting within two years was accepted with overwhelming enthusiasm. Congratulations for Probiotics ’96 and good luck with the organization of Probiotics ’98.
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(1) See BCCM™ News 1
Contact: Bruno Pot, BCCM™/LMG
E-mail: bruno.pot@rug.ac.be
Tel: +32 9 264 51 13
Fax: +32 9 264 53 46
In order to ensure the safe use of probiotics in food, the correct identification of the micro-organism(s) involved is essential. The BCCM™ collections offer identification, characterization and safe deposit services on a routine basis.
Several DNA-fingerprinting techniques (e.g. PFGE of rare-cutted restriction fragments, RAPD, AFLP™) are applied to produce strain-specific fingerprints.
The BCCM™/LMG has investigated more than 3 000 strains belonging to over 200 species of lactic acid bacteria by the one-dimensional SDS-PAGE technique of whole-cell proteins. The resulting database allows fast and reliable identification of the submitted strain to species or subspecies level. Numerical analysis of the protein profiles reveals the relative position of the strain towards a large number of well-known reference strains.
Strains of yeasts submitted to the BCCM™/MUCL are characterized and identified using BCCM™/ALLEV 2.00, an automated yeast identification system that employs both physiological and morphological criteria(1). Its reference database presently includes over 690 taxa and can be updated easily.
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(1) See ALLEV 2.00, BCCM™ News 1
Contact:
Bruno Pot, BCCM™/LMG
E-mail: bruno.pot@rug.ac.be
Tel: +32 9 264 51 13
Fax: +32 9 264 53 46
Vincent Robert, BCCM™/MUCL
E-mail: robert@mbla.ucl.ac.be
Tel. +32 10 47 37 42
Fax. +32 10 45 15 01
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