As a target group for specialised foods, the elderly have received little attention compared to other population groups yet they are set to make up a quarter of the total European population by 2020.
The most dramatic demographic changes are in the oldest age group (80 years and over) that is estimated to grow from 21.4 million in 2000 to 35 million in 2025.
The elderly are also at increased risk of a number of diseases, supporting a major role for functional foods that could help shore up their disease-fighting ability.
A three-year project, backed by €1.82 million in European Union funding, has produced preliminary results showing that a synbiotic supplement may be able to help prevent gastrointestinal disease in this population.
In the first of two studies under the Crownalife project, researchers in France, Italy, Germany and Sweden compared the make-up of bacteria in the gut of over-65s with a younger group of adults.
Data from this study is still being analysed but preliminary findings show that in some of the volunteers, such as those in France, the proportion of healthy bifidobacteria is lower in the elderly population.
In the second phase of the project, researchers at INRA in France and colleagues in Germany investigated whether taking a synbiotic supplement could improve these healthy bacteria levels.
They gave either a daily synbiotic supplement or a placebo to around 43 volunteers aged at least 65 years old in a double-blind, crossover study. The supplement contained Orafti's RaftiloseSynergy1 oligofructose-enriched inulin and a probiotic provided by Danone, bifidobacterium animalis.
After a four-week period the level of bifidobacteria increased significantly in the supplement group (by 3 per cent), the researchers reported.
"We also saw a positive effect on the wellbeing of the subjects," said nutrition research manager at Orafti, Douwina Bosscher. "We measured this using a dietary questionnaire on bowel habits and GI quality."
"It think the findings are very important because we are able to significantly increase levels of bifidobacterium. Previous research has shown that a decrease in levels of this bacteria may be associated with gastrointestinal disease."
Scientists have previously demonstrated that a combination of Orafti's product and probiotic cultures can help to protect people with early signs of colon cancer from developing the disease.
Bifidobacteria are thought to prevent colonisation of the gut by pathogens.
Results from the Crownalife project are expected to be published in scientific journals this year.