Tegan Taylor of ABC asks, what’s happening inside your body when you have food poisoning?

Research published today has given us a slightly clearer idea, at least for one type of bacteria.

A team from the Australian National University looked at the way the body responds to the bacteria Bacillus cereus, which can cause food poisoning and sometimes lead to serious infections elsewhere in the body, including sepsis, pneumonia and meningitis.

They found a toxin secreted by the bacteria binds directly to cells in the human body and punches holes in the cells to kill them, triggering an immune response.

Understanding the way toxins produced by this bacteria provoke inflammation in the body is a key to understanding how to treat it, said lead researcher Anukriti Mathur.

“Our immune system acts as a double-edged sword in these kinds of cases,” Ms Mathur said.

“In certain cases where you’ve got a bacterial infection it would be really essential to boost our immune system so that it is stronger.

“However in cases such as sepsis, where you’ve got unwanted inflammation happening in your body, you want to dampen the inflammatory responses.

“A very unique balance is required in protecting us against different kinds of infections.”

But what is it about this bacteria punching holes in your cells that leaves you hunched over a toilet bowl?

It has to do with the parts of your nervous system being targeted by the toxins produced by the bacteria, according to Vincent Ho, a University of Western Sydney gastroenterologist and researcher who was not involved in the study.

Bacillus cereus produces more than 12 different toxins. One triggers vomiting and another diarrhea, Dr Ho explained.

The vomit-inducing toxin, called cereulide, binds to serotonin receptors in the stomach and small bowel and stimulates the vagus nerve, which controls muscle movement in the gut.

“That signals back up to the vomiting centres of the brain,” he said.

“And in a very similar way that is how the diarrheal form also works too. It’s causing direct stimulation of the small bowel, and that’s triggering a reactive response of reflex mechanism called the gastro-colic reflex.

“The toxins are stimulating against receptors in the gut lining … triggering a lot more movement of the muscle in the gut and the colon.”

Bacillus cereus can be found in vegetables, rice and pasta, as well as meat and fish, and will grow in these foods if they are stored at the wrong temperature.