Next-generation sequencing can improve infant microbiota

Mar 17 2011

Sequencing technology has advanced significantly since the race to sequence the human genome first began. As part of the Teagasc Vision Programme a 'next generation sequencer', the only one of its kind in Ireland, was installed at Teagasc Food Research Centre, Moorepark.

This technology is being used to sequence microorganisms from one of the most extreme environments, i.e., the human gastrointestinal tract (gut). The human gut has the potential to impact hugely on the health of individuals. This is because microbes correspond to nine out of every ten cells in our body. Indeed, in the large intestine the number of microbes can be as high as 100 billion per gram. This collection of microbes is known as the human 'microbiome'. This microbiome contains 100 times more unique genes than those present in our own genomes, and has a metabolic capability equivalent to that of our liver.

"While everybody is aware that there are a number of gut microbes that can make us sick, the majority of gut microbes are harmless and, indeed, a significant number can have a positive impact on our health. It has only been since the advent of next-generation sequencing technologies that we have been able to properly appreciate what microbes are present in the gut and what they might be doing," explains Dr Paul Cotter in an article in TResearch, Teagasc's Science magazine.

These roles include vitamin synthesis, the digestion and absorption of foods, immunostimulation, the control of disease-causing microbes (pathogens) and prevention of other diseases, human intestinal cell proliferation, and aiding bowel movements. Now, armed with this knowledge, researchers at Teagasc can add considerably to the health claims, and thus value, associated with existing foods, and design the next generation of functional foods by identifying ingredients that impact positively on the composition of our gut microbiome and, in turn, our health.

While next-generation sequencing-based research of gut microbiomes will ultimately benefit all members of the population, to date there has been a particular emphasis at Teagasc on investigating and, where necessary, altering the microbiota present in the gut of the elderly, infants and obese individuals.

For example, evidence exists that early colonisation of the infant gastrointestinal tract by microbes is crucial for the overall health of the infant.

"The infant microbiota is influenced by factors such as the mode of delivery, the maternal microbiota, antibiotic exposure and other factors. Significantly, one of the major influencing factors is whether the infant is fed breast milk or infant milk formula. Breast milk is the ideal food for infants and contains a number of components that promote a healthy gut microbiota. Thus, producers of infant milk formula would like to generate new and improved formulae that more closely resemble breast milk with respect to its impact on the infant gut microbiota," explains Dr Cotter.

Ireland is a major player in the global infant formula industry, producing about 12% of global exports, and research in this area is of key importance with respect to maintaining, and further enhancing, Ireland's reputation in this area. Collaborative research between Teagasc, UCC and Cork University Maternity Hospital is employing next-generation sequencing technology to carry out research in this area.