Grant: Doctoral Research Award: Canada Graduate Scholarships

Approximately half of Canadians are affected by lactose intolerance, or the inability to digest lactose, a major component of milk and dairy products. Abdominal discomfort, bloating, gas, and diarrhea are the most common symptoms. However, more severe symptoms, including headaches, vomiting, malnutrition, and heart arrhythmias are also observed. Currently, the diagnosis of lactose intolerance is performed by giving a person with suspected lactose intolerance a large dose of lactose and measuring if hydrogen gas is produced. Undigested lactose is fermented by gut bacteria, and this produces many other chemicals in addition to hydrogen gas. To date, no comprehensive survey of the chemicals in the breath of lactose intolerant individuals following a lactose exposure has been reported. We expect to identify a number of new chemicals produced by gut bacteria fermenting undigested lactose. To study this, we will analyze the breath of lactose tolerant and intolerant individuals before and after a lactose exposure. Advanced breath sampling equipment and mass spectrometry will allow us to detect thousands of compounds in the breath simultaneously and will help us identify compounds specific to lactose intolerance. This work will improve our understanding of lactose intolerance, leading to better screening and treatment options.