Why does your stool sometimes float on water and not sink? New scientific research offers an explanation for this
Before we go further Nagarajan Kannan has a question for us ‘Does your faeces float or sink in water after it is passed out of the body?’
This is quite a strange question to hear.
But it is a question that interests Nagaranjan and his research on the matter has now become his personal research project. Let us also mention here that Nagranjan is the Director of the Stem Cell and Cancer Biology Laboratory at the Mayo Clinic in Minnesota.
Much of his day is spent researching the cellular and molecular mechanisms that cause breast cancer. But in his spare time, Nagarajan is engrossed in solving a different kind of puzzle, and that is why stool sometimes floats instead of sinking.
If you have an Indian commode in your toilet, it might be difficult for you to answer this question, but in the case of other commodes, you will definitely observe it.
However, sometimes pieces of faeces are not flushed, and even after flushing several times, the stool is not missed by the toilet. While many times the stool is completely submerged in the water in the commode and is easily flushed. But why does this happen?
Nagarajan Kannan believes that the answer gives us interesting information about the health of our body and the microbes (bacteria) that inhabit it.
Initially, it was believed that the fat content of faeces is the reason why they float in water. But in the early 1970s, two researchers at the University of Minnesota conducted a series of experiments to test this idea.
They put stools from 39 volunteers through several experiments, not even their own stools. As a result of these experiments, he found that the reason for the stool to float was not the fat but the gas in it.
More specifically, the amount of gas found in feces can vary to the extent that it either floats on the surface or sinks in water like a solid object, in addition to The amount of gas can be so limited that it neither fully floats nor floats, but also sinks and floats.
However, the researchers found that if they removed the gas from the stool, it completely sank.
The difference is due to the formation of methane gas, the researchers said.
And this is where Nagarajan Kannan enters the discussion. Since this first study, medical science has discovered that the microbiota in our bodies affects many things, from heart disease to obesity. Nagarajan believes that changes in the bacteria, fungi and other microorganisms in our gut are responsible for whether or not our stool will sink.
“The majority of faecal matter consists primarily of converted food particles that form a bacterial mass,” he says.
Results of an experiment conducted on mice
To test this theory, Nagarajan and his colleagues at the Mayo Clinic studied the feces of mice born and raised in a sterile environment. Since there were no microbes in the intestines of these mice, their feces immediately sank into the water. Meanwhile, 50 percent of the feces of mice that had the microbes in their intestines initially floated in water and then sank. When they studied it further, the reason became clear.
“Germ-free stools are full of sub-microscopic particles of undigested food and have a higher density than stools that are full of microbes,” says Nagarajan.
The researchers then performed ‘faecal transplants’ of germ-free mice from normal mice whose faeces floated in water, introducing them to intestinal bacteria. After that, the faeces of the previously sterile rats also started floating in the water.
When mice were introduced with human germs, their feces started floating on water.
Nagarajan says he thinks it doesn’t matter whether the germs come from humans or from somewhere else. Once they are introduced, rat feces start to float.
Nagarajan and his colleagues performed an extensive genetic analysis of the types of bacteria in the faeces of swimming rats and found high concentrations of ten types of bacteria known to cause gas. The majority of these are also ‘Bacteroides ovates’ which is known to produce gas through the fermentation of carbohydrates and is also associated with excessive flatulence in human patients.
Although the results from the mice must be viewed with caution, meaning their relevance to human sinking or floating faeces has yet to be confirmed, Nagarajan believes that the floating of our faeces can lead to changes in the different types of bacteria in our bodies. Could be a hint.
“I doubt that taking antibiotics makes floating stools sink,” he says.
But he adds that he has yet to see anyone doing research on the topic, adding that funding on the topic is difficult to get.
A number of factors can change the bacteria in our gut, including our diet, smoking habits, the stress we experience and the medications we take. Nagarajan now wants to explore just what causes the particular gas-producing bacteria to form.
“Whether you’re at a social gathering or on a space flight, you don’t want to be sitting next to someone whose intestines are full of gas-producing microbes,” he says.
Although it’s a dirty job, someone has to do it!