POC: Pocket-sized intestines – the HuMiX model enables intestinal flora to be investigated under real conditions

Researchers at the University of Luxembourg have developed a model of the human intestines which simplifies the examination of intestinal bacteria and removes the need for animal experiments. 

The human gut is up to eight metres long, but Paul Wilmes’ and Pranjul Shah’s model is only the size of a beer mat. “It may look very simple, but it’s packed full of know-how”, says Shah pointing to the small orange-white box on the table in front of him. You would never guess by looking at this small device that it has revolutionised intestinal tract research. But that’s precisely what it has done.

Pranjul Shah is a scientist at the Luxembourg Centre for Systems Biomedicine (LCSB), which is part of the University of Luxembourg, where this device was developed in the “HuMiX” research group led by FNR ATTRACT Fellow Professor Paul Wilmes. HuMiX stands for Human Microbial Cross-talk, and it is nothing less than the model of a human gut. The HuMiX organ-on-a-chip technology enables the complex interactions between human cells and bacteria to be analysed under the same conditions as those found in the human gut.

Finding out about changes that take place in bacteria

The organ-on-a-chip consists of three chambers which lie on top of each other and are separated from each other by a membrane. The human cells are in the middle chamber, and the lowest one is where the bacteria are kept. Liquid nutrient is pumped through the two outer cells, and its contents enter the neighbouring layers through the permeable membrane. This also enables the oxygen levels in HuMiX to be matched to the conditions found in the human gut.

“The cells and the bacteria are less than half a millimetre apart, but there is no physical contact”, Pranjul emphasises. And he says that this is extremely important. “After all, we don’t want to simulate an infection; we want to find out what changes take place in the bacteria and how that influences the cells”, he says.

Completely open system for carrying out investigations at any time

“In many cases we simply don’t know whether certain bacteria are the cause of an illness, or perhaps also the result of it”, he states. However, the organ-on-a-chip enables us to find that out. “The advantage is that we have a fully accessible system that we can investigate whenever we want to”, the researcher explains. “So we don’t have to use any test animals for investigations.”

According to Pranjul Shah, HuMiX also provides findings which can be translated more precisely to the human gut than tests on mice or piglets. Organs-on-a-chip like HuMiX could also propel research into other diseases, such as skin and lung diseases, as well as research into neurodegenerative diseases like Parkinson’s. For instance, the LCSB researchers have established that combined cultures of intestinal cells and certain bacteria lead to the formation of chemical messengers (neurotransmitters) for the nervous system. This result backs up the existing hypothesis that communication takes place between the gut and the brain. Issues like this are now easier to examine in the new, open HuMiX system than in mice.

Major contribution to eliminating animal experiments

HuMiX will therefore remove the need for future animal tests in microbiome research. Admittedly, not right across the board, but in many fields, which is why the LCSB researchers have recently been awarded the Lush Prize. Bestowed every year as the world’s most highly endowed prize in this field, it is awarded for test procedures and scientific work that contributes to doing away with animal experiments.

Scientists at the University of Luxembourg have proven that it works. The next step involves persuading the research departments in the pharmaceuticals, cosmetics and food industries to use HuMiX technology. Responsibility for this lies with the LCSB “Innovation Team”, which Pranjul Shah is also a member of. The team helps scientists with promising research projects to launch start-up companies and to collaborate with industry.

This success story is from the 2016 FNR Annual Report. View the Annual Report as PDF or digital version