“Why can some people eat like a horse and not gain weight, while others try hard to limit their diet and yet gain weight?”

   “Why can my best friend eat a double pepperoni pizza with no problem and I would be up all night doing so?”

   “Why do some nutrients, supplements or drugs work well for some people and not for other people?”

    In the early 1900s, scientists discovered that each person belonged to one of four blood types. 

    Now they have discovered a new way to classify people - by bacteria!  In the future, you may find, when you walk into a hospital, that you may be asked about your blood type, allergies and gut type.

Blood type, meet bug type.

   All human beings are host to thousands of different species of microbes.  Now, a group of scientists now report that there are three distinct ecosystems in the guts of people they have studied.  Scientists at the European Molecular Biology Laboratory (EMBL) in Heidelberg, Germany, have found that humans have three different gut types.  And it may not stop there.  Some are suggesting that there may be as many as seven general digestive catagories.  (For this article, we will go with the three types discussed here and report the others when verified.)

   “It’s an important advance,” said Rob Knight, a biologist at the University of Colorado.  “It’s the first indication that human gut ecosystems may fall into distinct types.”  Why is it so important?

Different digestive types probably determine
Why different people respond to diet,
Supplements and drugs differently!

    We all have bacteria in our gut that help digest food, break down toxins, produce some vitamins and essential amino acids, and form a barrier against invaders.  However, the composition of that microbial community - the relative numbers of different kinds of bacteria - varies from person to person.

Not by Gender or Race

   It was interesting that the research team, led by Peer Bork, found no link between what they call “enterotypes” (types of intestines activity) and ethnic backgrounds.  The European, American and Japanese subjects they studied showed no patterns by race.

   Nor could they find a connection to sex, weight, health or age. 

   Bork and colleagues found that all these cases could be divided into three groups, based on which species of bacteria occurred in high numbers in their gut.  Each person could be said to have one of three gut types, or enterotypes.

   Like blood groups, these gut types are independent of traits like age, gender, nationality and body-mass index.

   These studies showed different regions of the body were home to different combinations of species. From one person to another, scientists found more tremendous variety. Many of the species that lived in one person’s mouth, for example, were missing from another’s. "We found that the combination of microbes in the human intestine isn't random," says Peer Bork, who led the study at EMBL.

Why it Makes a Difference

   The discovery of the blood types A, B, AB and O had a major effect on how doctors practice medicine. They could limit the chances that a patient’s body would reject a blood transfusion by making sure the donated blood was of a matching type.

   Whatever the cause of the different enterotypes, they may also end up having discrete effects on people’s health.  Gut microbes aid in food digestion and synthesize vitamins, using enzymes our own cells cannot make.

   The discovery of enterotypes could someday lead to medical applications of its own, but they are down the road yet.  However, “Some things are pretty obvious already,” Dr. Bork said.  Doctors might be able to tailor diets or drug prescriptions to suit people’s enterotypes.  Dr. Bork and his colleagues found that each of the digestive types makes a unique balance of these enzymes.  For example:

Type 1 - produces more enzymes for making vitamin B7 (biotin), and had high levels of bacteria called Bacteroides . 

Type 2 - produces more enzymes for vitamin B1 (thiamine), and Bacteroides were relatively rare, while the genus Prevotella was unusually common.

   The study, published in Nature, also uncovers microbial genetic markers that could one day be used to help diagnose and predict outcomes for diseases like colo-rectal cancer.  Information about a person's gut type could help inform treatment.

   "The fact that there are bacterial genes associated with traits like age and weight indicates that there may also be markers for traits like obesity or diseases like colo-rectal cancer," Bork says, "which could have implications for diagnosis and prognosis."

   If this proves to be the case, when diagnosing or assessing the likelihood of a patient contracting a particular disease, doctors could look for clues not only in the patient's body but also in the bacteria that live in it. And after diagnosis, treatment could be adapted to the patient's gut type to ensure the best results.

   But the scientists did find for example, that the guts of older people appear to have more microbial genes involved in breaking down carbohydrates than those of youngsters, possibly because as we age we become less efficient at processing those nutrients, so in order to survive in the human gut, bacteria have to take up the task.

   Or, he speculated, doctors might be able to use enterotypes to find alternatives to antibiotics, which are becoming increasingly ineffective. Instead of trying to wipe out disease-causing bacteria that have disrupted the ecological balance of the gut, they could try to provide reinforcements for the good bacteria. “You’d try to restore the type you had before,” he said. Dr. Bork notes that more testing is necessary.

What it Means for Us

   We plan to keep on top of this developing research – though practical results are a way off yet.  This may have very good application for fine tuning correct application of supplements.  We look forward to an ever increasing improvement in the application of nutrients to optimal health.

   (Excerpts for the above story are from materials provided by European Molecular Biology Laboratory, via EurekAlert!, a service of AAAS.  Note: Materials may be edited for content and length. For further information, please contact the source cited above.)

References:

Arumugam, Raes, Pelletier, Paslier, et. al., Enterotypes of the human gut microbiome,  Nature, Volume: 473, Pages: 174–180, Date published: 12 May 2011,  DOI: doi:10.1038/nature09944

Ruth E. Ley1, Daniel A. Peterson and Jeffrey I. Gordon,  Ecological and Evolutionary Forces Shaping Microbial Diversity in the Human Intestine,  Center for Genome Sciences, Washington University School of Medicine, St. Louis, MO 63108, USA.