Controlling gut bacteria, for example by dietary modification, offers the prospect of improving health, especially in elderly people.

In recent years, scientists have shown that the large numbers of bacteria that are always carried in the human gut are important for our health. They are involved in extracting energy from our food, making certain vitamins, keeping dangerous bacteria at bay, and even fine-tuning or own defence mechanisms or immune system.

As people age, these beneficial properties of the gut bacteria appear to weaken, and the immune system also slows down. It's not clear which body defence functions and defence mechanisms are most dependent on gut bacteria - which is what ELDERMET plans to find out!

We will study the relationship between diet, gut bacteria and health status in a large number of elderly (>65 years) Irish subjects, mainly from the Munster region. We will use the findings to make recommendations for diet and food ingredients, to the benefit of Irish consumers and the Irish food industry.

The intestinal microbial flora (or microbiota) has an important role in human health. As well as interacting with the diet, gut bacteria can also play more complex roles such as modulation of the immune system. In addition, the composition of the microbiota may be important for reducing gut infections.

Changes in the microbiota over the life of the individual are accompanied by changes in multiple heath parameters, and there is intense activity at international level to understand this complex interaction.

To develop the potential of the diet for promoting intestinal health, knowledge of the baseline composition of the human gut microbiota is required. In this landmark study, we will use cutting-edge sequencing technology to determine the composition of the faecal microbiota in 500 elderly Irish subjects. We will determine what bacterial profiles correlate with health, dietary or lifestyle factors.

To increase the statistical power of correlations identified, uniquely we will then follow 250 subjects serially for two further time-points, to characterize both intra- and inter-individual variation in the gut microbiota. We will test representative health groupings by metagenomic sequence of the gut microbiome which we will correlate to metabolomic profiling of human samples. This information will provide the Irish Food Industry and Medical Community with an essential platform consisting of the bacterial composition of healthy elderly individuals, and how it may be positively modulated through nutritional and/or probiotic/prebiotic approaches