This is a randomized, double-blind placebo controlled trial to evaluate the effect of a probiotic (Bl-04) on the occurrence of rhinovirus-associated common cold illness in the experimental rhinovirus challenge model. A previous study documented that Bl-04 has significant effects on the innate immune response in the nose and this study will be powered to assess whether these effects translate into a demonstrable clinical benefit. Volunteers will be given Bl-04 or placebo for 28 days then challenged with rhinovirus. The primary analysis will be on the proportion of volunteers who develop a rhinovirus associated illness in the two treatment groups.

Inclusion Criteria:

INCLUSION CRITERIA AT ENROLLMENT:

• Subject must be 18-60 years of age.
• Subject must read and sign a copy of the approved Consent Form
• Subject must have a serum neutralizing antibody titer of less than or equal to 1:4 to rhinovirus type 39

INCLUSION CRITERIA AT DAY -28

• Female subjects must be using an effective birth control method.

INCLUSION CRITERIA AT CHALLENGE:

• Female subjects must be using an effective birth control method.

Exclusion Criteria:

• Antibiotic use within 3 months prior to day -28

  • Female subjects with a positive urine pregnancy screen
  • History of use of probiotics in the preceding two weeks
  • Current cancer diagnosis or immunosuppressive therapy in the last 6 months
  • Any clinically significant abnormalities of the upper respiratory tract
  • Any clinically significant acute or chronic respiratory illness
  • Any clinically significant bleeding tendency by history
  • Hypertension that requires treatment with antihypertensive medications
  • History of angina or other clinically significant cardiac disease
  • Any medical condition that in the opinion of the Principal Investigator is cause for exclusion from the study
  • History of regular use (more than 3 days in 7) of tobacco products within the preceding two weeks
  • History of drug or alcohol abuse in the 6 months preceding the study

EXCLUSION CRITERIA AT CHALLENGE:

• Any upper respiratory infection or allergic rhinitis in the two weeks prior to the challenge
• Female subjects with positive pregnancy screen prior to challenge
• Any medical condition that in the opinion of the Principal Investigator is cause for exclusion from the study
• Use of any anti-inflammatory (steroids or NSAIDs) or cough/cold or allergy preparation in the two weeks prior to the challenge

Consent/screening through the final study visit on study day 21-28.

For the purposes of this study using experimental rhinovirus infection, physical signs and symptoms that are expected to be associated with the common cold should not be reported as adverse events. The following physical signs and symptoms are expected to be associated with the common cold: nasal obstruction (nasal stuffiness), coryza (runny nose), sore throat, cough, sneezing, myalgia, headache, feverishness, chills, loss of appetite and malaise.