The answer to this question is actually very important. The speed at which food passes through the digestive tract affects our health and well-being, says Nick Aylott, a biotechnologist and bioinformatician from the University of Oxford.
What Did the Expert Report?
According to the scientist, once food is chewed and swallowed, it embarks on a long and winding journey through the gastrointestinal tract. Along the way, food encounters organs that digest it (the stomach), absorb nutrients (the small intestine), and extract water and salts (the large intestine).
The movement of food through the digestive tract is known as intestinal peristalsis. This process is partially controlled by trillions of bacteria. The gut microbiome is incredibly important, as it helps develop the immune system and break down food.
So, we’re not just feeding ourselves – we’re also nourishing the tiny helpers residing in our intestines. In return, these bacteria produce small molecules called metabolites, which strengthen the immune system and stimulate the intestines to contract, pushing food further along.
Without bacteria and their metabolites, our intestines would be less capable of moving food through the gastrointestinal tract. This would lead to a buildup of swallowed material, simply put, constipation.
Transit Time of Food Through the Intestines
This transit time varies among individuals. Recent estimates suggest that the passage of food can take anywhere from 12 to 73 hours, with an average time of about 23-24 hours, according to Science Alert.
Many factors influence how long food takes to move through the intestines, including genetics, diet, and the gut microbiome.
If intestinal peristalsis is slow, bacteria in the large intestine produce different metabolites. This happens because, like us, bacteria need nourishment. Typically, these bacteria prefer fiber. However, if the transit time through the intestines is too long, these microbial residents have to switch to an alternative food source, such as protein.
Switching to protein can lead to the production of toxic gases, resulting in issues like bloating and inflammation.
Slow transit can also cause partially digested food to get stuck in the small intestine. This poses a risk of excessive bacterial growth there, as well as abdominal pain, nausea, and bloating.
Interestingly, accelerated transit through the intestines can also negatively impact health. Causes of overly rapid transit include anxiety, inflammatory bowel disease, and irritable bowel syndrome. The harmful effects of fast food transportation include inadequate nutrient absorption and dehydration.
The Corn Test
Nick Aylott suggested a very simple test to check intestinal motility. Its name is just as straightforward – the “corn test,” and so is the process.
Before starting the test, you should avoid eating corn for 7-10 days (the “washout” phase). Then, record the date and time when you begin the experiment, after which you should eat a small amount of corn (a handful is sufficient).
The outer shells of corn kernels are not digested. However, they will travel through the entire gastrointestinal tract along with other food, and at the final stage, they can be observed. You should note the date and time when this occurs.
If the shells exit within 12 hours or sooner, the intestines are functioning rapidly. If they do not exit within 48 hours or longer, the intestines are functioning slowly. Generally, these processes can be adjusted on your own.
For example, if transit is slow but there are no concerning symptoms (such as bloating, abdominal pain, loss of appetite, or nausea), you should drink plenty of water and engage in physical activity. Additionally, eating more fruits and vegetables can increase fiber intake to nourish beneficial gut bacteria.
The key to good intestinal function is maintaining a balanced diet.
Of course, if issues with food transit occur regularly, it’s important to consult a doctor.
According to the expert, this home test is comparable in its results to more complex research methods.