March 9, 2023 – By Tick Tock Kombucha tea: Gut health is an enormous priority straight away – in spite of everything, we’ve been hearing about it for years. And rightly so.
Your gut – and its diverse mixture of bacteria, often called the microbiome – is not any longer only for digestion. The “health” of your gut can also be linked to the health of your heart, your brain, your immune system and more.
The problem: Much about what goes on there, which bacteria populate it through which concentrations – and learn how to interpret all of that – stays a mystery. Studying the gut is difficult. Animal testing might not be useful because animals have different digestive enzymes and gut bacteria than humans. And typical laboratory tests, comparable to growing cells in a petri dish, don’t capture how complex the gut is, a component of the body where many kinds of cells grow and interact in a moist, fluid, oxygen-free environment.
A brand new technology called “gut on a chip” guarantees to alter all that. It opens the door to experiments that were previously unattainable and guarantees to advance medical research, says a brand new article in APL Bioengineering.
Your intestine on a chip
It is considered one of the most recent advances in organ-on-a-chip technology, which involves placing human cells right into a device that mimics the activity of human organs. Scientists have developed models to simulate organs comparable to the lungs, kidneys and vagina.
To construct an intestine on a chip, scientists grow cells from intestinal tissue and bacteria.
“These cells don't grow easily,” says study creator Amin Valiei, PhD, a postdoctoral fellow on the University of California, Berkeley. “They need a special environment.”
To create this environment, researchers place the cells in tiny channels that allow fluid flow and mimic the forces present within the gut. This means the cells can interact with one another as they’d within the human body.
“These models are becoming more and more advanced,” says Valiei. “Compared to a few years ago, we now have models that can accommodate multiple cell types.”
Why this is essential: medications, diseases and dysbiosis
Researchers can conduct experiments on the models that might be difficult or unattainable on humans.
“These devices could be particularly useful at the hypothesis stage to test new drugs and therapeutics,” says Valiei.
Valiei and his colleagues at UC Berkeley’s Molecular Cell Biomechanics Lab are studying how several types of bacteria interact in these gut chip models. In particular, they’re investigating how certain harmful bacteria can establish themselves within the gut – a phenomenon often called Dysbiosis This has been linked to plenty of conditions, including inflammatory bowel disease (IBD), irritable bowel syndrome (IBS), diabetes, obesity, cancer and heart problems.
Researchers are also using gut-on-a-chip models to review IBD, colon cancer, and even the results of viruses like COVID-19 on gut function.
To understand how disease develops, we want to interrupt things down into basic steps, and gut-on-a-chip models could help researchers do this, says Christopher Chang, MD, a gastroenterologist on the Raymond G. Murphy VA Medical Center in Albuquerque, NM, and the University of New Mexico. (Chang was not involved within the study.)
“We can identify literally thousands of species in the gut and know roughly which microbes are considered beneficial and which are not,” he says.
But how do individual bacteria fit right into a community? And which mixtures result in a healthy gut versus an unhealthy one? Answers to those questions remain unclear.
“We have ways to manipulate the microbiome, through various antibiotics, probiotics and stool microbiota transplants,” says Chang. “But we need to know: what should we manipulate?”
Room for improvement
One a part of the gut that just isn’t yet depicted in gut chip models is the enteric nervous system, also often called our “second brain” – neurons embedded within the gastrointestinal tract, Chang says. This is how the gut and brain communicate with one another, and dysfunction is linked to gut diseases comparable to irritable bowel syndrome.
People with irritable bowel syndrome could have pain, diarrhea, or constipation despite the fact that their intestinal tissue looks normal on biopsies. Gut-on-a-chip models could also be less helpful in understanding these conditions, but could still help answer basic questions.
The gut-brain connection remains to be being explored, so because the science advances, researchers may find a way to contribute recent insights to future gut-on-a-chip models.
Gut-on-a-chip models is also useful beyond disease research, Valiei says. Every drug we swallow passes through our gastrointestinal tract. If researchers can use gut-on-a-chip models to determine exactly how we digest and absorb drugs, they might refine the way in which we use those drugs.
The push is now underway to deploy this technology on a big scale. Because more research must be done, the technology must be refined, and enough data must be collected to satisfy regulators, it could be several years before one of these “precision medicine” is precise enough to be truly personalized for patients. But in line with Valiei, this is definitely an in depth taste of what's to return.