A new study says that an individual’s intestinal bacteria flora organizes itself in certain clusters and they hypothesize this intestinal bacteria flora will have an influence on how we react to diet and medicine absorbed through the gastro-intestinal tract.

Most people know about blood types, some also know about tissue types but intestinal bacteria types is unheard of by the general public.   The researchers studied 278 volunteers in total from Denmark, Italy, Spain, France, Japan and USA  and, using 22 newly sequenced fecal metagenomes (yes, that is just what you think it is), mapped 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 utilize 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 results published in Nature do not show anything about the precise mechanisms by which the three enterotypes individually affect people that host the bacteria and more intestinal bacteria clusters will most likely be added to the three enterotypes which have been identified so far.  The discovery of their existence gives researchers new opportunities for studying how gut bacteria affects our health. 

“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."

Citation: Manimozhiyan Arumugam, Jeroen Raes, Eric Pelletier, Denis Le Paslier, Takuji Yamada, Daniel R. Mende, Gabriel R. Fernandes, Julien Tap, Thomas Bruls, Jean-Michel Batto, Marcelo Bertalan, Natalia Borruel, Francesc Casellas, Leyden Fernandez, Laurent Gautier, Torben Hansen, Masahira Hattori, Tetsuya Hayashi, Michiel Kleerebezem, Ken Kurokawa, Marion Leclerc, Florence Levenez, Chaysavanh Manichanh, H. Bjørn Nielsen, Trine Nielsen, 'Enterotypes of the human gut microbiome', Nature (2011) doi:10.1038/nature09944