Resistance to simulated gastrointestinal conditions and adhesion to mucus as probiotic criteria for Bifidobacterium longum strains.
Eight Bifidobacterium longum strains, including reported probiotic strains (commercial and noncommercial), collection strains, and laboratory isolates, were investigated for their ability to adhere to mucin as well as their ability to tolerate acid and bile. Strains could be discriminated based on their sensitivity at pH values of 2.0 to 2.5 and bile concentrations of 0.5% to 2.0%. B. longum NCC 2705, a strain known for its probiotic properties, showed the highest resistance to gastrointestinal conditions, whereas the commercial probiotic strains B. longum BB 536 and SP 07/3 were the least resistant. In parallel, the human isolate B. longum BIF 53 showed the highest adhesion to mucin, whereas the commercial probiotic strains B. longum W 11, BB 536, and SP 07/3 were the least adhesive. The bacterial adhesion to mucin of strains B. longum NCC 2705 and BIF 53 could be reduced by lysozyme, indicating that cell-wall components are involved in the adhesion process. These results showed that there is no obvious link between adhesion and resistance to gastrointestinal conditions and the probiotic status of the studied strains. This calls for a definition of conditions for in vitro tests that better predict the in vivo functionality of probiotic strains.
Izquierdo
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Instituto de Agroquímica y Tecnología de Alimentos, 46015, Burjassot-Valencia, Spain.
Medina
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Ennahar
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Marchioni
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Sanz
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Y
D000818:Animals; D001422:Bacterial Adhesion; D001644:Bifidobacterium / Q000254:growth & development / Q000302:isolation & purification / Q000502:physiology*; D001647:Bile Acids and Salts / Q000378:metabolism*; D005753:Gastric Mucosa / Q000378:metabolism / Q000382:microbiology*; D005765:Gastrointestinal Agents / Q000378:metabolism*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D050296:Microbial Viability / Q000187:drug effects; D009077:Mucins / Q000378:metabolism; D010434:Pepsin A / Q000378:metabolism*; D019936:Probiotics / Q000737:chemistry* / Q000302:isolation & purification; D013552:Swine
D001647:Bile Acids and Salts; D005765:Gastrointestinal Agents; D009077:Mucins; D010434:Pepsin A