Examining the effects of probiotics on the immune system.

Name of intervention, dose and duration: The effect of probiotics on immune regulatory function, Six commercially available probiotics will be examined (one probiotic per study group): Eczema shield (Ethical Nutrients) – 2 capsules per day (2x10^10 cfu/day, Lactobacillus rhamnosus) for 14 days Travel bug (Ethical Nutrients) – 2 capsules per day (1 x 10^10 cfu/day, Saccharomyces boulardii) for 14 days Mutaflor (Natural Therapy Imports) - 2 capsules twice a day (1 x 10^10 cfu twice a day, E. coli Nissle 1917 ) for 14 days Bifidobacteria lactis – 2 capsules per day (1 x 10^10 cfu/day) for 14 days Streptococcus thermophilus – dry powder 100 billion cfu per g (2 x 10^10 cfu per day, i.e. 200mg per day) for 14 days Bifidobacteria breve – dry powder 100 billion cfu per g (2 x 10^10 cfu per day, i.e. 200mg per day) for 14 days Mode of adminstration: Oral Personalised intervention: No Intervention adherence: Compliance will be monitored by capsule counts and by completion of a daily diary of doses taken. Diaries will be reviewed at Day 8 and Day 15 and missed doses recorded. Non-compliance will be defined as missing more than 1 dose. The study nurse will assess compliance.