title: Probiotic potential of lactic acid bacteria present in home made curd in southern India.
abstract: OBJECTIVE
  The human gut microbiota play a significant role in nutritional processes. The concept of probiotics has led to widespread consumption of food preparations containing probiotic microbes such as curd and yogurt. Curd prepared at home is consumed every day in most homes in southern India. In this study the home-made curd was evaluated for lactic acid bacteria (LAB) with probiotic potential.
  
  
  METHODS
  Fifteen LAB (12 lactobacilli, 1 l0 actococcus , 2 Leuconostoc) and one yeast isolated from home-made curd were evaluated for resistance to acid, pepsin, pancreatin and bile salts; antimicrobial resistance; intrinsic antimicrobial activity; adherence to Caco-2 epithelial cells; ability to block pathogen adherence to Caco-2 cells; ability to inhibit interleukin (IL)-8 secretion from HT-29 epithelial cells in response to Vibrio cholerae; and ability to induce anti-inflammatory cytokine expression in THP-1 monocyte cells.
  
  
  RESULTS
  Lactobacillus abundance in fermenting curd peaked sharply at 12 h. Nine of the strains survived exposure to acid (pH 3.0) for at least one hour, and all strains survived in the presence of pancreatin or bile salts for 3 h. None showed haemolytic activity. All were resistant to most antimicrobials tested, but were sensitive to imipenem. Most strains inhibited the growth of Salmonella Typhimurium while five inhibited growth of V. cholerae O139. Seven strains showed adherence to Caco-2 cells ranging from 20-104 per cent of adherence of an adherent strain of Escherichia coli, but all inhibited V. cholerae adherence to Caco-2 cells by 20-100 per cent. They inhibited interleukin-8 secretion from HT-29 cells, in response to V. cholerae, by 50-80 per cent. Two strains induced IL-10 and IL-12 messenger ribonucleic acid (mRNA) expression in THP-1 cells.
  
  
  CONCLUSIONS
  LAB in curd had properties consistent with probiotic potential, but these were not consistent across species. LAB abundance in curd increased rapidly at 12 h of fermentation at room temperature and declined thereafter.
authors.forename: Ramadass
authors.initials: R
authors.lastname: Balamurugan
authors.forename: Aarthi Sophia
authors.initials: AS
authors.lastname: Chandragunasekaran
authors.forename: Gowri
authors.initials: G
authors.lastname: Chellappan
authors.forename: Krithika
authors.initials: K
authors.lastname: Rajaram
authors.forename: Gayathri
authors.initials: G
authors.lastname: Ramamoorthi
authors.affiliation: The Wellcome Trust Research Laboratory, Department of Gastrointestinal Sciences, Christian Medical College, Vellore, India.
authors.forename: Balakrishnan S
authors.initials: BS
authors.lastname: Ramakrishna
mesh_terms: D018938:Caco-2 Cells; D005243:Feces / Q000382:microbiology; D005285:Fermentation; D005516:Food Microbiology; D019073:HT29 Cells; D006801:Humans; D007194:India; D018664:Interleukin-12 / Q000378:metabolism; D019344:Lactic Acid / Q000378:metabolism*; D007778:Lactobacillus / Q000378:metabolism*; D064307:Microbiota / Q000502:physiology; D019936:Probiotics / Q000008:administration & dosage*; D012486:Salmonella typhimurium / Q000187:drug effects; D015014:Yogurt / Q000382:microbiology
chemical_list: D018664:Interleukin-12; D019344:Lactic Acid