Intestinal Bacteria Organize in Clusters

As partners in the international research consortium named MetaHit, scientists from the University of Copenhagen have contributed to show that an individual's intestinal bacteria flora, regardless of nationality, gender and age, organizes itself in certain clusters. The cluster of intestinal bacteria flora is hypothesized to have an influence on how we react to both our diet and medicine absorbed through the gastro-intestinal tract. The results have recently been published in the journal Nature.

Most people know about blood types, some also know about tissue types. However, now we may need to consider intestinal bacteria types as well. As part of a large, international research consortium, scientists from the University of Copenhagen have recently contributed to map special "enterotypes," which are three distinctive clusters of bacteria in the human distal gut. Each of these enterotypes reflects a certain balance between various categories of bacteria in the distal gut, and is thought to impact intestinal bacteria digest food leavings, and utilise these for energy delivery to the gut and the whole body energy metabolism, and on how various drugs are absorbed through the gastrointestinal tract.

"The discovery of enterotypes is expected to influence future research within a number of fields," explains professor Oluf Borbye Pedersen, professor at Novo Nordisk Foundation Center for Basic Metabolic Research at the Faculty of Health Sciences, the University of Copenhagen, and also one of the lead investigators in the international research consortium MetaHIT, which has conducted the project.

"Our results show that we may have uncovered a new 'biological fingerprint' on the same level as blood types and tissue types. The three enterotypes occur across nationalities and are independent of gender and age. Every enterotype has a certain composition of bacteria that have specific functions, for example energy production from degradation of dietary fibres or formation of certain vitamins. This may potentially affect a number of biological functions discoveries which at a later stage may be translated into individual diet advice or design of drugs that are adapted to the individual enterotype," Pedersen adds.

He emphasizes that the results published in Nature do not show anything about the precise mechanisms by which the three enterotypes individually affect people that host the bacteria. After further research, more intestinal bacteria clusters will most likely be added to the three enterotypes, which have been identified so far. However, the discovery of their existence gives researchers new opportunities for studying how the about 1.5-kilo gut bacteria, which we all have in our digestive system, affects our health.

The researchers from MetaHIT, an international EU-supported project, have studied 278 volunteers in total from Denmark, Italy, Spain, France, Japan and USA for the paper in Nature. From Denmark, several scientists have contributed from the Novo Nordisk Foundation Center for Basic Metabolic Research at Faculty of Health Sciences, University of Copenhagen; the Lundbeck Foundations Genomics Center, LuCamp; and from the Center for Biological Sequence Analysis, Institute for System Biology at the Technical University of Denmark.