A galaxy within us – our gut microbiota and how it can be programmed by food
Who would have thought that the human body contains over 10 times the amount of bacterial cells as human cells? These bacteria - now collectively called the gut microbiota - number in their trillions and are made up of more than a 1,000 different species most of which are beneficial in some way.
“Research is starting to show that the food we eat has a huge bearing on the composition of this collective and also that the profile of the collection of bacteria can be associated with a person’s health status,” explains Dr Paul Ross, Head of the Teagasc Food Research Programme and Principal Investigator at the Alimentary Pharmabiotic Centre, Teagasc, Food Research Centre, Moorepark.
To the team at the Alimentary Pharmabiotic Centre (APC), an SFI-funded CSET at Teagasc, Food Research Centre, Moorepark and at University College Cork, the study of the human microbiota has the potential to transform much of the thinking around basic human nutrition, gut health and disease prevention: “This has been made possible through developments made in DNA sequencing technology which has allowed the study of complex microbial communities such as the human gut microbiota, the majority of which cannot be cultured on an individual basis,” explains Dr Ross.
Although the composition of the microbiota is highly stable during adulthood, there are times when it can be highly dynamic – such as at the extremes of life, e.g., following birth, during inflammatory bowel conditions, gastrointestinal infection and in the elderly. Despite this stability, the microbiota also displays a high degree of interindividual variation reflecting differences in lifestyle, diet, host genetics, etc.
In a project called ELDERMET, a team of UCC/Teagasc scientists headed by Professor Paul O’Toole has recently profiled the faecal microbiota from elderly people in different residences including community, day-hospital, rehabilitation or long-term residential care locations.
This study found that the microbiota correlated with the residence location. “The results demonstrated that the individual microbiota of people in long-stay care was significantly less diverse than those that resided in the community,” explains Dr Ross. “In addition, these subjects were also clustered by diet by the same residence location and microbiota groupings. Interestingly, the separation of microbiota composition correlated significantly with health parameters in these individuals including measures of frailty, co-morbidity, nutritional status, markers of inflammation and with metabolites in faecal water”.
Taken together these data suggest that diet can programme the gut microbiota – the composition of which correlates with health status. Such a suggestion opens up great potential for the food industry in the design of food ingredients and supplements which may in the future shape the microbiota in a particular direction to correlate with an improved consumer health status. Interestingly, a related study called INFANTMET, funded by the Department of Agriculture, Food and the Marine and led by Professor Catherine Stanton at Teagasc Moorepark, is looking at the development of the gut microbiota in early life as a consequence of breast feeding.
“This study will be of great interest to our Infant Formula Industry which produces approximately 12% of global exports in this sector. From a national perspective, Ireland is perfectly positioned to capture and capitalise on what is one of the most exciting areas in biological research as the country expands its Agrifood Industry to produce a greater variety of value-added food products to benefit the health of the modern consumer,” explains Dr Ross.