Something Old, Something New

Probiotics are living microorganisms that, when they successfully colonize specific niches of the human body, provide a wide range of benefits. These include nutritional contributions, support for immune function, and the ability to compete against harmful microorganisms that can compromise health. Among the body sites inhabited by beneficial microbes, the gastrointestinal tract is arguably the most critical, serving as a complex ecosystem in which microbial communities influence digestion, immunity, and overall well-being. In recent years, the search for new probiotic strains has become increasingly relevant as scientists explore microbiome-based solutions to improve human health and combat infectious diseases. 
As a UNU-BIOLAC Fellow, João Vitor Wagner Ordine investigated the probiotic potential of Lactobacillus strains isolated from buffalo milk, evaluating their capacity to survive conditions similar to those found in the human digestive tract and to inhibit clinically relevant enteric pathogens. Working at the Institut Pasteur Montevideo, he screened dozens of isolates using classical microbiological approaches, focusing on key probiotic traits such as resistance to strong acidic environments, tolerance to bile salts, biofilm-forming capacity, and antagonistic activity against pathogenic bacteria, including antimicrobial-resistant enteropathogens. The study identified multiple strains exhibiting remarkable inhibitory effects against pathogens including Klebsiella pneumoniae, Escherichia coli, and Clostridium perfringens. 
A particularly valuable aspect of this fellowship was the integration of traditional microbiological phenotyping with cutting-edge genomic technologies. João employed whole-genome sequencing and bioinformatic analyses to investigate the molecular mechanisms underlying their beneficial traits. This combination of phenotypic and genomic characterization enables researchers to rapidly identify genes associated with antimicrobial compound production, host colonization, stress tolerance, and competitive exclusion of pathogens. Beyond accelerating the development of microbiome-based therapies that improve quality of life and prevent disease, these approaches also enhance the discovery of novel antimicrobial compounds, urgently needed amid the growing global crisis of antimicrobial resistance (AMR).
UNU-BIOLAC congratulates João Vitor Wagner Ordine on the successful completion of this fellowship and gratefully acknowledges the guidance of Dr. Nadia Riera at Institut Pasteur Montevideo and Dr. Lívia Soares Zaramela of the Ribeirão Preto Medical School, University of São Paulo (USP).