News, Culture & Society

New ‘light therapy’ could treat constipation better than drugs

Shining a blue light into the colon could treat constipation better than laxatives do, a new study suggests.  

About 16 percent of Americans suffer chronic constipation, and the condition is on the rise. 

The Color Toner Experts

The US is in the midst of a gastrointestinal crisis and, while there are plenty of over-the-counter laxatives available, these drugs can also cause other gut trouble if they’re used for too long. 

Now, researchers in Australia and at the Washington University in St Louis, Missouri have discovered that introducing certain proteins to the gut can make it sensitive to light, which, in turn, stimulates the bowels into action.

Scientists in Australia and at Washington University genetically engineered mice’s guts to respond to blue light (pictured), making their bowels move and eliminating constipation 

Some 63 million people in the US regularly have to cope with cramping and feeling backed up, bloated and uncomfortable on a regular basis.   

Chronic constipation has become a bigger problem for Americans whose diets full of processed foods and saturated fats fuel both obesity and gastrointestinal troubles. 

Numbers of constipation cases are also stacking up as the American population – namely, the baby boomer generation – ages. 

Approximately one third of people over 65 experience constipation and, for some, the condition even proves deadly. 

At first blush the wide availability of over-the-counter drugs to treat constipation seems to be a positive, but this also means that use of these medications goes mostly unsupervised by health care professionals. 

And laxatives are no light matter. 

For those who have chronic or frequent constipation, long-term use of some of these drugs can interfere with the bodies natural balance of salts and minerals. 

Some of these, particularly stimulant laxatives can engender dependence, diminishing regular bowel functionality. 

Stimulant laxatives excite the neurons that line the bowel, literally making the bowel move to alleviate constipation. 

They are effective, and safe for most, but can have those serious side effects, as well as more common ones like diarrhea. 

‘Commonly used treatments use a lot of chemicals and most of the chemicals have multiple [effects] on multiple cells, and have a lot of side effects,’ explained co-lead author Dr Hongzhen Hu.


Dr Rob Knight, co-founder of the American Gut Project, said his team is working on many ‘science fiction’ ideas to revolutionize how we understand our personal gut health. 

He tabled three ideas which he is exploring to work towards:

  1. A ‘smart toilet’ that examines your fecal matter and offers a live report of ‘how you’re doing’
  2. A ‘smart mirror’ that gives an analysis of your breath when you breathe on it, much like the cystic fibrosis breath tests available
  3. An app synced with your smart toilet that could scan grocery items while you’re shopping, and can tell you what you should buy to eat 

‘That’s why we came up with with the idea that maybe if we use light stimulation of gut neurons, we can stimulate and improve gut motility.’ 

Postdoctoral fellow Dr Jing Feng spearheaded the development of the optogenetics the Washington University team used to make mice’s guts sensitive to light.

In brief, optogenetics is a technique by which scientists alter an animals genetics by infusing them with light-sensitive proteins.  

Neurons essentially communicate through electricity, firing off signals when there is a change in their ionic charges. 

Optogenetics allow scientists to use blue light like a manual ‘on’ switch that triggers neural action. 

Dr Feng and his team genetically engineered mice to have the light sensitive neurons in their guts, using proteins extracted from algae. 

When the researchers shined the blue light onto the bellies of the mice or directly onto their colons, the neurons were ‘excited,’ or switched on, and the mice’s bowels moved. 

Shining light onto the mice for 30 minutes to an hour or shining it directly on removed colons for just a few seconds quickly eliminated constipation. 

‘[With these findings] combined, we believe that light stimulation is a very smart way to promote gastrointestinal motility in mice and could potentially be used in humans in future if figured out how to put these light sensitive enteric neurons in humans,’ said Dr Hu.   

These neurons can currently only be introduced through genetic engineering, which makes the treatment impossible for humans – for now.

‘We cannot do it because we are biologists and have no access to human patients, but we do see a lot of interest around the world, with people asking if we want volunteers,’ said Dr Hu. 

‘But it has to be done by physicians or in collaboration with physicians, but I do feel like this is the future direction.’ 

Unlike some gut treatments that only require dietary changes or supplements to introduce new bacteria to he gut microbiome, these proteins have to be introduced through genetic modification. 

But that may not be that far off, said Dr Hu, with gene therapies being used to treat more and more diseases, ailments and health conditions.

Dr Hu said that the mice’s bodies are small enough to use frequencies of blue light shined from outside their bodies to get their colons moving, but too small to use a colonscope – the tube with a light and camera on one end used in colonoscopies – to do so. 

‘But for humans, you could put the scope inside the colon because it is bigger and, in theory, it would be quick in humans using a colon scope,’ Dr Hu said.  


Comments are closed.