Mengdi Zhao, Yueyao Li, Yuanyuan Zhang, Guangyu Li
{"title":"Genomic analysis and functional properties of Lactobacillus johnsonii GJ231 isolated from healthy beagles","authors":"Mengdi Zhao, Yueyao Li, Yuanyuan Zhang, Guangyu Li","doi":"10.3389/fmicb.2024.1437036","DOIUrl":null,"url":null,"abstract":"Probiotics are one of the management tools to improve the host’s healthy microbiota. The positive effects of probiotics on host health are species-specific, so probiotics isolated from host’s own gut may be most beneficial. Many of the metabolites (e.g., short-chain fatty acids, bacteriocins, and hydrogen peroxide) produced by <jats:italic>Lactobacillus johnsonii</jats:italic> have specific inhibitory profiles against invading pathogens. In this study, we isolated <jats:italic>L. johnsonii</jats:italic> GJ231 from the intestinal tract of healthy female beagles. The genome size of 1.763 M encoded a total of 1,691 predicted genes. Many carbohydrate-active enzymes responsible for carbohydrate degradation and the production of short-chain fatty acids were also predicted. The metabolic profile of short-chain fatty acids in <jats:italic>L. johnsonii</jats:italic> GJ231 was determined using LC–MS/MS. The bacteriocin-producing gene bacteriocin (lactacin F) in <jats:italic>L. johnsonii</jats:italic> GJ231 was also predicted. <jats:italic>In vitro</jats:italic>, experiments demonstrated that GJ231 can thrive in weak acids, 0.3% bile salts, and artificial gastrointestinal fluid models. It was tolerant of to high temperatures up to 70°C, was non- hemolytic, inhibited pathogenic bacteria, and had a high antioxidant capacity. <jats:italic>In vivo</jats:italic> safety experiments conducted in mice revealed that oral administration of GJ231 not only had no toxic side effect but also increased their antioxidant capacity. In conclusion, combining the above test results, which collectively demonstrate that canine-derived <jats:italic>L. johnsonii</jats:italic> GJ231 was a non-pathogenic, acid-tolerant and bile-salt-tolerant probiotic strain that inhibits pathogenic bacteria and improves host antioxidant function. This may make it a promising candidate for the development of innovative functional foods for pets.","PeriodicalId":12466,"journal":{"name":"Frontiers in Microbiology","volume":null,"pages":null},"PeriodicalIF":4.0000,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Frontiers in Microbiology","FirstCategoryId":"99","ListUrlMain":"https://doi.org/10.3389/fmicb.2024.1437036","RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"MICROBIOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Probiotics are one of the management tools to improve the host’s healthy microbiota. The positive effects of probiotics on host health are species-specific, so probiotics isolated from host’s own gut may be most beneficial. Many of the metabolites (e.g., short-chain fatty acids, bacteriocins, and hydrogen peroxide) produced by Lactobacillus johnsonii have specific inhibitory profiles against invading pathogens. In this study, we isolated L. johnsonii GJ231 from the intestinal tract of healthy female beagles. The genome size of 1.763 M encoded a total of 1,691 predicted genes. Many carbohydrate-active enzymes responsible for carbohydrate degradation and the production of short-chain fatty acids were also predicted. The metabolic profile of short-chain fatty acids in L. johnsonii GJ231 was determined using LC–MS/MS. The bacteriocin-producing gene bacteriocin (lactacin F) in L. johnsonii GJ231 was also predicted. In vitro, experiments demonstrated that GJ231 can thrive in weak acids, 0.3% bile salts, and artificial gastrointestinal fluid models. It was tolerant of to high temperatures up to 70°C, was non- hemolytic, inhibited pathogenic bacteria, and had a high antioxidant capacity. In vivo safety experiments conducted in mice revealed that oral administration of GJ231 not only had no toxic side effect but also increased their antioxidant capacity. In conclusion, combining the above test results, which collectively demonstrate that canine-derived L. johnsonii GJ231 was a non-pathogenic, acid-tolerant and bile-salt-tolerant probiotic strain that inhibits pathogenic bacteria and improves host antioxidant function. This may make it a promising candidate for the development of innovative functional foods for pets.
期刊介绍:
Frontiers in Microbiology is a leading journal in its field, publishing rigorously peer-reviewed research across the entire spectrum of microbiology. Field Chief Editor Martin G. Klotz at Washington State University is supported by an outstanding Editorial Board of international researchers. This multidisciplinary open-access journal is at the forefront of disseminating and communicating scientific knowledge and impactful discoveries to researchers, academics, clinicians and the public worldwide.