A rice dish left on a warm kitchen counter overnight put a healthy man in his twenties on the urgent list for a new liver. Reheating it did not help: the toxin that did the damage is not destroyed by heat

Most people who have had food poisoning from rice remember a miserable afternoon of vomiting and not much else. A case report from Erasmus MC in Rotterdam, published in BMJ Case Reports on 5 October 2026, is a reminder that the same toxin can, very rarely, do far worse. It describes a man in his early twenties with no medical history who came within days of an emergency liver transplant after eating a home-cooked rice dish.

The dish had been made the day before and, by accident, left out on the kitchen counter during a Dutch summer, with the room above 30 °C. The next evening it was reheated and eaten. He felt unwell after dinner and went to bed early. In the morning a family member found him unresponsive and having a seizure. The ambulance crew's glucose meter could not even give a number, the reading was so low. His brother had eaten the same rice and spent up to two days with vomiting and diarrhoea.

In hospital things moved fast. Lactic acid built up in his blood until it reached 18 mmol/L; in a healthy person at rest it is below about 2. His liver enzymes, which in a healthy adult usually sit below about 50 units per litre, passed 17,000. His blood stopped clotting properly, ammonia that a working liver would clear rose to 251 µmol/L, and his kidneys began to fail. He was put on a ventilator and dialysis, needed drugs to hold up his blood pressure, and was placed on Eurotransplant's high-urgency list for a new liver.

For the first days nobody knew why. The team tested for viruses, drugs including paracetamol, alcohol, autoimmune disease, inherited metabolic disorders, blood clots in the liver's veins and a long list of infections, and found nothing. The answer came from the family. Talking to them in more detail, the doctors learned about the rice. And his parents had kept a leftover portion and frozen it soon after the meal.

That frozen portion is what makes this report unusual. With help from Wageningen Food Safety Research, the rice was tested for cereulide, a toxin made by the soil bacterium Bacillus cereus. It held 9,600 to 38,400 micrograms per kilogram, 100 to 400 times above the highest level the laboratory's method can measure precisely. The bacterium in the rice carried the genes for making cereulide and belonged to a type known for producing a lot of it. A blood sample taken about 18 hours after the meal also contained the toxin, which shows it got into his body and was already in the food when he ate it, not made later in the leftovers.

The way it happens is simple. Bacillus cereus spores are common on rice and other dry foods and survive harvesting, milling and boiling. Once cooked rice sits warm and moist, the spores wake up, multiply and make cereulide. The toxin is a small ring-shaped molecule that resists heat, acid and digestive enzymes, so reheating the rice, however thoroughly, does not break it down. Inside the body it lets potassium leak across the membranes of mitochondria, the parts of the cell that make energy. The liver, packed with mitochondria and the first organ to receive what the gut absorbs, takes the biggest hit.

Why was one brother so much sicker than the other? The authors think vomiting is usually the body's defence: it gets most of the toxin out before much is absorbed. The brother vomited. The patient did not; he lay down and fell asleep, which probably let far more reach his bloodstream. That is the authors' explanation and it fits, but it cannot be proved from two people.

He got better. On day 3 his liver tests began to improve and on day 4 he came off the transplant list. His brain took longer. When sedation was lightened he barely responded and had bouts of stiffness and shaking; by day 10 he could follow instructions but was slow to think, struggled to find words and was weak and tremulous. The doctors put this down to the ammonia the failing liver had let build up in his brain. After 12 days he moved to a local hospital and went home 14 days after that. He has since gone back to work and to sport, has no sign of lasting liver damage, and is left only with a mild tremor in his hands.

Some caution is in order. This is one patient, and the authors say plainly that a single case cannot prove cause and effect; their conclusion rests on the timing, the toxin in the food and in his blood, and the absence of any other explanation. His stool was never tested, so an unusual infection cannot be completely ruled out. Several treatments were given at once, so nothing can be said about which one helped. And cases this severe are rare: the authors count only a small number in the medical literature. The ordinary outcome of eating badly stored rice is the brother's, not his. But the fix is easy and costs nothing. The UK Food Standards Agency advises cooling leftover rice quickly, ideally within an hour, in small portions rather than in the cooker or pan, keeping it in the fridge for no more than a day, and reheating it only once, until it is steaming hot all the way through.