Bifidobacterium longum bv. infantis CCUG 52486 combined with gluco-oligosaccharide significantly reduces the duration of self-reported cold and flu-like symptoms among healthy older adults after seasonal influenza vaccination

The potential health benefits of both pre‐ and probiotics have expanded in recent years from maintaining bowel regularity and a balance of gut microflora to improving micronutrient status and immune function. There is particular interest in the positive influences of pre‐ and probiotics in older people, who are subject to alteration in gut microbiota composition and also to immunosenescence (deterioration and dysregulation of the immune system). The PRIMAGE study is a randomised, double‐blind, placebo‐controlled, parallel study investigating the influence of Bifidobacterium longum bv. Infantis CCUG 52486 (5x108 CFU/d) combined with gluco‐oligosaccharide (8 g/d) on the immune response to influenza vaccination among healthy young (18‐35 y, n = 58) and older (60‐85 y, n = 54) volunteers. Volunteers consumed either a placebo (9 g/d maltodextrin) or treatment for a total of 8 weeks, and a trivalent influenza vaccination (2010/2011 northern hemisphere) was administered after 4 wks of treatment. Blood and faecal samples were collected at baseline, week 4 and after vaccination. Older volunteers were asked to complete a self‐reported illness form for six months post‐vaccination. 43 healthy older volunteers were vaccinated in October/November 2010 in accordance with UK NHS vaccination schedules, and 41 returned a six‐month self‐reported illness form. Treatment did not significantly alter the incidence of cold or flu‐like symptoms. Three participants within the treatment group reported a sudden onset of flu like illness, resulting in a significantly higher duration of this symptom among volunteers on treatment in the six months post‐vaccination (p = 0.0047). Volunteers receiving treatment had significantly lower cumulative duration of fatigue, runny nose, headache and sore throat symptoms during the six months post‐vaccination compared to placebo (p<0.0001).