BELGIUM – Diet, medication, sex, age and transit time in the gut are the variables that most influence their flora, as pointed out by one of the largest studies to date on these stocks. The findings published in Science reveal associations between the composition of the intestinal flora and consumption of beer or black chocolate, among other discoveries.

Through the analysis of more than one thousand human stool samples, a team of researchers from the Institute of Biotechnology of Flanders (Belgium), directed by Jeroen Raes, has identified 69 factors related to the composition of the flora. Most of these variables are related to the transit time it takes to get food from the mouth to the end of intestine; diet, medication, sex and age.

Together with his team, Raes mapped the composition of the intestinal flora of about 5,000 volunteers in Flanders. The purpose was to analyze the links between human intestinal flora and health, and lifestyle.

The findings provide important information for future research and clinical trials information.  Integration with other data collected in the world reveals a set of 14 genera of bacteria that make the universal essence of microbiota in all individuals.

“Our work has given a huge amount of new information about the composition of the microbiota of normal people like you and me,” Raes says. “Most previous studies focused on specific diseases or in a much smaller geographical area “he adds.

However, analysis of the ‘average’ intestinal flora is essential for the development of diagnostics and medicines based on intestinal bacteria. “You need to understand what is normal before we can understand and treat the disease,” adds Raes.

Belgian chocolate effect

By analyzing factor by factor, the transit time of feces showed the strongest unravel when the composition of the flora association. Diet is also important, mainly in relation to consumption of fiber factor.

In addition, it was found that a particular group of bacteria had a preference for black chocolate. “The effect of Belgian chocolate,” jokes Raes.  An association between the composition of the intestinal flora and consumption of beer was also found.

The medication also had a strong link with the profile of the intestinal flora. However, other results of the project require deeper, as the relation between intestinal flora and factors related to oxygen absorption capacity research.

Breastfeeding does not influence

The researchers not only identified an association with antibiotics and laxatives, but also with drugs hay fever and hormones used for contraception or for the relief of symptoms of menopause.

Surprisingly, the mode of birth (vaginal delivery or cesarean) or breast-feeding was not reflected in the composition of the adult microbiota.

Importance of results and collaborations

“These results are essential to study diseases such as Parkinson’s, which is typically associated with intestinal transit time, which in turn has an impact on the composition of the microbiota,” says Raes.

Collaboration with the Dutch LifeLines study allowed researchers to reproduce his results. Thus, over 90% of the identified factors were also detected in the Dutch cohort.

International collaborations is the key to advance the field and accelerate the development path based on gut flora drugs. “Replication adds great strength to the results,” emphasizes Raes.

Although the project has greatly enriched the knowledge of its composition, this only allowed to explain the 7% of its variation, there is still much work to be done to outline the entire ecosystem of this flora.

Raes Laboratory estimated that about 40,000 human samples will be needed just to capture a complete picture of the biodiversity of the intestinal flora. The authors are already planning follow-up studies to explore the development of the intestinal flora in time.