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Swallowable sensors reveal stomach’s ‘immune system’

The stomach may have its own immune system that fights off foreign invaders that stay in our digestive system too long, a new invention helped scientists discover.

Researchers at RMIT University in Melbourne, Australia conducted the first human trials of tiny devices that, after being swallowed, detect changes in gas levels in the stomach to provide feedback about gut health. 

Information was transmitted from inside peoples’ guts to mobile phones, where the researchers could observe their digestion in real time. 

With one in five people in the world suffering from a gastrointestinal disorder over the course of their lives, the new technology could be a game-changer for diagnostics and prevention. 

Eat up: These tiny sensors are safe for humans to swallow, and send information about what is going on in the gut to cellphones

The gut has become one of the hottest body parts for study recently and some research has hailed it as ‘the second brain.’ 

Now, evidence is mounting that it acts a second immune system, too. 

The sensors the Australian researchers designed could provide a new, painless way to monitor even subtle changes in the gut that could indicate the pivotal moment the digestive system changes from healthy to problematic.  

‘Previously, we have had to rely on fecal samples or surgery to sample and analyse microbes in the gut,’ said Dr Kourosh Kalantar-Zadeh, study co-author and one of the inventors of the sensor.

‘But this meant measuring them when they are not a true reflection of the gut microbiota at that time. 

‘Our capsule will offer a non-invasive method to measure microbiome activity,’ he said. 

Already, the real-time feedback has revealed previously unknown gut activities. 

By measuring gasses released by particular processes in the stomach, the researchers found that the organ was oxidizing certain compounds. 

What oxidation does for your immune system  

Oxidation is a process that removes electrons from a cell. 

When that happens, the cell’s membrane becomes damaged and the cell dies. 

White blood cells identify and attack bacteria and other foreign bodies in our systems using oxidation to disable the invaders. 

However, fighting infection takes a toll on the body. 

So-called ‘oxidative stress’ produces free radicals that may contribute to the aging process and development of cancer – as well as being responsible for our hair turning grey. 

Antioxidant foods and supplements may help to fight this process, but well-balanced oxidation processes are key to a good immune system to keep us healthy. 

Oxidation can be stressful to the body, especially when it is happening too frequently, and scientists think that it may stress cells, contributing to aging, cancer and the development of heart disease.

As a result, antioxidants have gotten a lot of hype as being a way to combat these inevitable damages. 

But our bodies need to have a balanced degree of oxidation. Oxidation is a process that takes away electrons from a cell, effectively disarming it.

White blood cells use oxidation to destroy bacteria cells when they invade the body.

The new sensor technology revealed that the stomach also initiates oxidizing processes. 

‘We found that the stomach releases oxidizing chemicals to break down and beat foreign compounds that are staying in the stomach for longer than usual,’ Dr Kalantar-Zadeh said.

In other words, the stomach appears to ‘know’ when something has overstayed its welcome, and is not responding to typical digestion in the way that normal food compounds should.  

‘This could represent a gastric protection system against foreign bodies. Such an immune mechanism has never been reported before,’ he added. 

Historically, it has been believed that our colons do not have any oxygen in them, but the new tiny electronic monitors revealed that this was not the case. 

‘Trials showed the presence of high concentrations of oxygen in the colon under an extremely high-fiber diet,’ Dr Kalantar-Zadeh said.

‘This contradicts the old belief that the colon is always oxygen-free [and the] new information could help us better understand how debilitating diseases like colon cancer occur,’ he explained.