Professor Tim Spector stared into the toilet bowl, forgetting for a moment that he had eaten a muffin filled with food coloring. From the well of water the contents of his intestines poked in a shocking shade of electric blue.
Spector, a professor of genetic epidemiology at King’s College London and author of The Diet Myth, urges the public to follow suit and eat blue-colored muffins to monitor their intestinal transit times. This is the time it takes for food to get from your mouth to the other end.
The aim is to educate people about their biology, especially their gut health, and get them to talk about the glamorous subject of poo.
Prof. Spector was involved in a study published in the medical journal Gut in which 863 healthy people ate foods with blue coloring to monitor intestinal transit times. It found that longer intestinal transit times were generally associated with undesirable bacteria, while shorter transit times indicated healthier intestines.
Professor Tim Spector
The gut microbiome is critical to our health, says Prof. Spector. Think of it as a bit like a community of microbes made up of things like microorganisms, bacteria, viruses, and fungi. “There are trillions of these people and they are critical to many parts of our body that run well,” says Prof. Spector. “This includes things like the good digestion of food, the storage of fat, our state of mind, whether we are hungry or full, and this is also very important for our immune system.”
He wants people to eat blue colored food – specifically two blue muffins – and then how long it takes for them to have bluish green poop. This is one of the “easiest ways” to get an idea of what’s going on in your gut, he says, because you can monitor exactly how fast your body is processing it.
How to participate
1. Bake your own muffins (with food coloring) at home. eat two for breakfast and start your timer.
2. Look for blue-green droppings when you go to the bathroom. Make a note of the time you discover them.
3. Get your results and discover your “poo personality” on the Blue Poop Challenge website.
We know from research by Prof. Spector that shorter intestinal transit times of around 20 hours indicate a healthier and happier intestine, while longer transit times (30+ hours) indicate an unhealthy microbiome.
People with constipation have a slow intestinal transit time. “They are generally more likely to have poor gut health and bad microbes,” says Prof. Spector. “This study showed that there is … a clear correlation between a fast transit time and a healthy selection of different microbes that are good for your health.”
His study suggests that intestinal transit times are a more meaningful indicator of your gut microbiome function than traditional measures currently in use, such as the Bristol Stool Chart. (You may remember it from a trip to see your GP. The poster shows you different types of droppings, from hard, rabbit-like stones to liquid mud. Patients are asked to choose which of these seven types they are.)
Ultimately, Prof. Spector hopes the #BluePoopCampaign will get people to talk a little more about their bowel movements – because we’re pretty shitty compared to other countries.
“We want to educate people so that they can talk about intestinal health without embarrassment,” says Prof. Spector, who admits that he carried out this experiment himself a few times. “It’s always a shock because I forget until I look in the bathroom,” he laughs. “It’s a shocking blue!” Its intestinal transit time is around 18 hours, which is pretty healthy.
What if my intestinal transit time is too slow?
If you participate and find that your transit time is slow, there are four changes you can make to improve your gut microbiome (and make things faster).
1. Eat more diverse types of plants. Ideally, you should be eating 30 plants a week, says Prof. Spector, including fruits, vegetables, nuts, seeds, and herbs. This helps improve the diversity of your gut microbiome while also giving you plenty of fiber to make things move.
2. Pick brightly colored plants to eat. Prof. Spector notes that foods with polyphenols are great. Think: colorful berries, apples, nuts, green lettuce, apricots.
3. Eat more fermented foods like yogurt as well as the four Ks: kefir, kombucha, kimchi and cabbage (or sauerkraut).
4th Avoid ultra processed foods as these are bad for intestinal health. Ultra-processed foods are not simply “modified foods” – like frozen or canned foods – but foods that have undergone multiple processes that “result in” little or no intact whole foods “. Examples include candy, packaged snacks like cookies and chips, ready meals, and soft drinks.