狗狗经过训练能嗅出某些人类疾病

狗是人类最好的朋友，也可能是人类健康最大的盟友。《今日医学新闻》报道称，越来越多的狗用于训练嗅出癌症、糖尿病、细菌感染和其他健康问题。

Man's best friend may friend also be his best health ally（伙伴，同盟）. Medical News Today reports a rise in the number dogs trained to sniff out cancer, diabetic conditions, bacterial infections, and other health problems.

Research from the UK charity Medical Detection Dogs and the US organization Dogs4Diabetes has found dogs are being used to alert their diabetic owners when their blood sugar levels are too low (hypoglycemic血糖过低的). Other research has found dogs are able to detect clostridium difficile -- a nasty bacterial infection that causes may illnesses acquired in hospitals -- in patient stool samples and hospital air. 

New research is also examining at the use of dogs to detect various types of cancer -- named "bio-detection dogs." Earlier this year, Medical News Today detailed how researchers have found dogs are able to detect volatile organic compounds (VOCs), or odorants, that are altered in the early stages of ovarian（卵巢的） cancer. Another study conducted by researchers at Medical Detection Dogs also found that these VOCs are biomarkers for bladder cancer.

Using four trained sniffer dogs to analyze urine samples from patients who had bladder cancer, alongside healthy people, the researchers found that the dogs were able to detect the cancer with an accuracy level that ranged from 56 percent to 92 percent.

A dog has up to 300 million scent glands (a human has about 5 million), which makes a dog's sense of smell up to 100,000 times more sensitive. 

"We believe all diseases have scent associated with the diseases, due to the changes occurring within the body, with different organs expressing different chemical compounds," Ralph Hendrix, executive director of Dogs4Diabetics, told Medical News Today. "These scents are evident in breath and sweat."