Scientists with UNC Greensboro Center for Translational Biomedical Research and the David H. Murdock Research Institute (DHMRI), both located at the NC Research Campus in Kannapolis, in partnership with scientists from Shanghai Jiao Tong University in Shanghai, China and the Imperial College of London, United Kingdom have shed light on why so many babies who drank melamine-tainted milk in 2008 did not die. The paper Melamine-induced renal toxicity is mediated by the gut microbiota published in the journal Science Translational Medicine in February 2013 also adds to the body of scientific literature that points to the importance of gut microbiota to human health.
Melamine is an industrial chemical used in fire retardant and plastics. In 2007, dogs and cats were poisoned from melamine-tainted pet food. In 2008, numerous manufactures in China added melamine to powdered and fresh milk products, including baby formula, to make the protein content appear higher. Over 300,000 infants were sickened but only six died, each of renal failure.
Scientists who conducted the study concluded that the bacteria Klebsiella terrigena was the culprit. Scientists reached this finding by feeding rats antibiotics for four days before exposing them to melamine. The rats that had ingested the antibiotics excreted more melamine and experienced less kidney stones than the rats not given antibiotics. Rats exposed to Klebsiella and then fed melamine experienced higher rates of kidney damage.
By analyzing the excrement from the rats, scientists discovered that Klebsiella converted melamine into cyanuric acid. Cyanuric acid was found in the kidneys of the babies that died and caused the fatal kidney stones, renal toxicity and renal failure. Only one percent of people have Klebsiella in their gut microbiota, which correlates to the fact that less than one percent of the infants who drink the tainted milk products died.
For more details about the study, read:
Melamine-Induced Renal Toxicity Is Mediated by the Gut Microbiota, Science AAAS
Gut Bacteria Conspired in Melamine Poisoning, by Science AAAS staff writer Elizabeth Pennisi
Study finds clues to why most babies in China survived melamine-tainted milk in 2008 scandal,
by Lauran Neergaard, Associated Press
Gut Microbes Could Influence Survival in Melamine Scandal, by David Tan, Asian Scientist