Why are people eating blue muffins and checking out their poo afterwards? The BluePoo viral trend on social media is linked to a challenge on the ZOE website where you eat two homemade blue muffins for breakfast to assess how well your digestive system (gut) is working.
We last talked about the importance of our gut health in a previous Pharmhealth blog and how your “movements” are critical to your wellbeing and mood. The gut contains 100 million nerve cells (neurons), so no wonder it is referred to as our second brain, and our primary brain’s feel-good chemicals like serotonin are also synthesised in the gut. While your two brains are entirely distinct, they are both wired electrically.
This latest #bluepoopchallenge involves making muffins according to a specific recipe which includes the addition of blue food colouring (gel not water based). You measure how long after eating the muffin it takes for the blue colour to show in your poo. How long it takes from eating until excretion is known as “gut transit time” and this can be used to assess how well your bowel is working. It is based on a published study by scientists from King’s College London1.
This study was carried out on healthy adults with the aim to find an inexpensive and scaleable method of measuring gut transit time. Too long or too short a transit time can indicate that perhaps your bowel is not working as efficiently as it should. If this is the case, maybe you should be looking at the foods you eat or supplements you may need to assist the gut microbiome.
Our digestive tract naturally contains trillions of good and bad micro-organisms known as our “gut microbiome”, and no two humans’ microbiomes are the same, not even identical twins. Obviously, the good ones help to maintain a healthy gut and these can be present from birth or introduced by our diet. Avoid ultra-processed foods and add ferment able carbohydrates like garlic, leeks, asparagus and chicory root into your diet, as these are more effective in the process of re-balancing the gut. Gut-friendly microbes are also found in some fermented food items such as yogurt, kefir, miso, sauerkraut, and kimchi. Pre-biotics and pro-biotics are also available in the form of supplemental tablets or capsules that can be ingested daily.
It could be useful to re-do the challenge a number of weeks after introducing changes to your diet, to see if there has been an improvement.
However, it is important to note that the challenge is not medical advice and doesn’t aim to diagnose, prevent or treat any disease. But at the very least it’s an interesting way to start a conversation about gut health.
As always, if you have any concerns feel free to talk to the team at Pharmhealth or your local GP.

1Asnicar F, Leeming ER, Dimidi E, et al. Blue poo: impact of gut transit time on the gut microbiome using a novel marker Gut 2021;70:1665-1674.