Development of a Probiotic Strategy to Prevent or Eliminate Nasal Colonization With S. Aureus

Inclusion Criteria: * Male and female subjects aged 18 years or older * On a stable hemodialysis schedule three times a week at Tufts Medical Center outpatient hemodialysis unit * Able to speak English, Spanish, Cantonese, or Mandarin (One of these languages is spoken by \>95% of our hemodialysis population) * Provides informed consent to participate in the study * No plans to be absent from the dialysis unit in the next 6 months * Willingness to report on adverse events during the study period Exclusion Criteria: * Patients in which hemodialysis was indicated for acute renal failure secondary to septic shock, acute tubular necrosis, or other condition which is felt to be temporary or secondary to a life threatening illness or likelihood of hemodialysis for less than 6 months. * Treatment with systemic anti-staphylococcal antibiotic therapy within 30 days prior to enrollment or planned use of topical mupirocin applied to the nares * Receiving peritoneal dialysis (concordance between the colonizing and infecting strain is not as high as in the hemodialysis population (105)) * Absolute neutrophil count less than 500/mm3 or anticipated fall in neutrophil count \< 500/mm3 (e.g. as a result of recent chemotherapy) * Bleeding diathesis such as platelets count less than 20 or INR \>4 within the last 30 days * On immunosuppressive therapy * Anticipated renal transplant during the next 6 months * Evidence of active bowel leak, acute abdomen or colitis