{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,11,5]],"date-time":"2026-11-05T17:47:49Z","timestamp":1793900869210,"version":"4.8.0"},"reference-count":32,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2026,2,12]],"date-time":"2026-02-12T00:00:00Z","timestamp":1770854400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Sao Paulo Research Foundation","award":["2023\/05394-9"],"award-info":[{"award-number":["2023\/05394-9"]}]},{"name":"Sao Paulo Research Foundation","award":["2024\/01721-8"],"award-info":[{"award-number":["2024\/01721-8"]}]},{"name":"Sao Paulo Research Foundation","award":["2024\/13311-9"],"award-info":[{"award-number":["2024\/13311-9"]}]},{"name":"Sao Paulo Research Foundation","award":["2024\/08823-0"],"award-info":[{"award-number":["2024\/08823-0"]}]},{"name":"Centre for Research and Development in Agrifood Systems and Sustainability","award":["UIDB\/05937\/2020"],"award-info":[{"award-number":["UIDB\/05937\/2020"]}]},{"name":"Centre for Research and Development in Agrifood Systems and Sustainability","award":["UIDP\/05937\/2020"],"award-info":[{"award-number":["UIDP\/05937\/2020"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Foods"],"abstract":"<jats:p>This study evaluated the viability, microbiological composition, functional traits, and safety of probiotic bacteria isolated from commercial products marketed as containing Limosilactobacillus reuteri. Viable cell counts, biochemical characterization, strain-level identification, functional properties, gastrointestinal tolerance, and safety attributes were assessed. Among the evaluated products, only four presented colony-forming units (CFU) counts consistent with label claims (products E, F, G, and H), while two showed no detectable viable microorganisms (products B and L). All isolates were Gram-positive, catalase-negative, and predominantly rod-shaped. rep-PCR analysis revealed strain homogeneity in most products, whereas others (products A and K) exhibited heterogeneous microbial compositions. Molecular identification based on 16S rRNA sequencing showed a predominance of Lmb. reuteri and Lacticaseibacillus rhamnosus, with some products containing additional species such as Lactiplantibacillus plantarum and Lactobacillus acidophilus. Functional assays demonstrated strain-dependent proteolytic and diacetyl-producing capacities, as well as variable tolerance to simulated gastrointestinal conditions. Most strains preferentially produced L-lactate, although some generated substantial amounts of D-lactate. All isolates were susceptible to antibiotics recommended by EFSA, except for intrinsic vancomycin resistance, and no transferable virulence markers, biogenic amine production, or Salmonella contamination were detected. Furthermore, virulence-related genes such as hdc, tdc, odc, hyl, cylA, and ace were not identified. Overall, the results highlight pronounced discrepancies between label claims and microbiological quality among commercial probiotic products and reinforce the importance of strain-level characterization to ensure safety, functional performance, and regulatory compliance.<\/jats:p>","DOI":"10.3390\/foods15040674","type":"journal-article","created":{"date-parts":[[2026,2,12]],"date-time":"2026-02-12T14:06:16Z","timestamp":1770905176000},"page":"674","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":5,"title":["Isolation, Identification, and Validation of Strains from Commercial Probiotics: Do We Get What We Expect?"],"prefix":"10.3390","volume":"15","author":[{"given":"Isabella Somera","family":"de Oliveira e Silva","sequence":"first","affiliation":[{"name":"ProBacLab, Laborat\u00f3rio de Microbiologia de Alimentos, Departamento de Alimentos e Nutri\u00e7\u00e3o Experimental, Food Research Center, Faculdade de Ci\u00eancias Farmac\u00eauticas, Universidade de S\u00e3o Paulo, S\u00e3o Paulo, SP 05508-000, Brazil"},{"name":"Faculty of Pharmaceutical Sciences, Faculdades Oswaldo Cruz, Rua Brigadeiro Galv\u00e3o, 540, Sao Paulo, SP 01151-000, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8768-4772","authenticated-orcid":false,"given":"Em\u00edlia Maria Fran\u00e7a","family":"Lima","sequence":"additional","affiliation":[{"name":"ProBacLab, Laborat\u00f3rio de Microbiologia de Alimentos, Departamento de Alimentos e Nutri\u00e7\u00e3o Experimental, Food Research Center, Faculdade de Ci\u00eancias Farmac\u00eauticas, Universidade de S\u00e3o Paulo, S\u00e3o Paulo, SP 05508-000, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Katia","family":"Leani","sequence":"additional","affiliation":[{"name":"ProBacLab, Laborat\u00f3rio de Microbiologia de Alimentos, Departamento de Alimentos e Nutri\u00e7\u00e3o Experimental, Food Research Center, Faculdade de Ci\u00eancias Farmac\u00eauticas, Universidade de S\u00e3o Paulo, S\u00e3o Paulo, SP 05508-000, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6377-3305","authenticated-orcid":false,"given":"Svetoslav Dimitrov","family":"Todorov","sequence":"additional","affiliation":[{"name":"ProBacLab, Laborat\u00f3rio de Microbiologia de Alimentos, Departamento de Alimentos e Nutri\u00e7\u00e3o Experimental, Food Research Center, Faculdade de Ci\u00eancias Farmac\u00eauticas, Universidade de S\u00e3o Paulo, S\u00e3o Paulo, SP 05508-000, Brazil"},{"name":"Department of General Hygiene, Sechenov First Moscow State Medical University, Trubetskaya Str. 8, Bldg. 2, Moscow 119991, Russia"},{"name":"CISAS\u2014Center for Research and Development in Agrifood Systems and Sustainability, Instituto Polit\u00e9cnico de Viana do Castelo, 4900-347 Viana do Castelo, Portugal"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,2,12]]},"reference":[{"key":"ref_1","unstructured":"FAO, and WHO (2001). 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