Gut microbiota influence on healthy ageing

The ageing process leads to a potential decline in immune function and adversely affects the gut microbiota. To date, many in vitro and in vivo studies have focused on the application of synbiotic (prebiotics combined with probiotics) as a promising dietary approach to affect gut microbiota composition and improved functioning of the immune system. In this study, researchers from the University of Reading used a synbiotic (as well as the separate probiotic and prebiotic) in a volunteer study.


A total of 80 potential healthy volunteers (aged 60–80 years) were contacted from the University of Reading and surrounding area through the Hugh Sinclair Unit of Human Nutrition.

Researchers investigated the effects of a probiotic Lactobacillus rhamnosus GG and pilus-deficient L. rhamnosus GG-PB12 combined with Soluble Corn Fibre (SCF, a candidate prebiotic) on faecal microbiota, metabolism, immunity, and blood lipids in healthy elderly persons. A prospective, double-blind, placebo controlled, randomised, single-centred, crossover study in 40 healthy elderly subjects (aged 60–80 years) was carried out. Volunteers were randomised to consume either probiotic and prebiotic as synbiotic, prebiotic or placebo (maltodextrin) during 3 weeks. Three-week washout periods separated all the treatments. Researchers assessed the effects upon blood lipids, glucose, cytokines, natural killer (NK) cell activity, phenotype, and intestinal microbiota composition.

Outcomes and Impact

The synbiotic combination showed a tendency to promote innate immunity by increasing NK cell activity in elderly women and in 70 to 80-year-old volunteers and decreased TC and LDL-c in hypercholesterolemic patients. In addition, L. rhamnosus GG-PB12 combined with SCF demonstrated an increase in NK cell activity compared to SCF alone in older volunteers. Researchers also found significant positive effects on the immune response, evidenced by a decrease of the pro-inflammatory cytokine IL-6. In the faecal microbiota analyses, L. rhamnosus GG combined with SCF and L. rhamnosus GG-PB12 combined with SCF significantly increased the genus Parabacteroides. Therefore, dietary intervention using this symbiotic could be of importance in the elderly as an attractive option for the enhancement of both the microbial and immune systems.

Key university staff

Professor Glenn Gibson, Professor of Food Microbiology, Head of Food Microbial Sciences, School of Chemistry, Food & Pharmacy, University of Reading

Related Publications

Effects of soluble corn fiber alone or in synbiotic combination with Lactobacillus rhamnosus GG and the Pilus-deficient derivative GG-PB12 on fecal microbiota, metabolism, and markers of immune function: a randomized, double-blind, placebo-controlled, crossover study in healthy elderly (Saimes study). Frontiers in Immunology, 8. 1443. ISSN 1664-3224