With probiotics a hot topic of conversation everywhere from health and fitness magazines and celebrity blog posts to supermarket aisles, many Canadians are aware of what they are — good bacteria that helps keep the digestive tract healthy. But few people have heard about prebiotics, which also play a pivotal role in maintaining gut health.

Prebiotics are a specialized type of plant fibre that is not digested and stimulates the growth and maintenance of good bacteria in the colon. Prebiotics are like “food” for probiotics and the two are more effective in improving digestive health when combined.

Studies have shown that everyone has a different mix of bacteria in their gut. Improving the good-to-bad bacteria ratio in the gut has many benefits including enhanced gastrointestinal health, which is great news for the 20 million Canadians who suffer from digestive disorders.

“Prebiotics have a positive effect on our well-being,” says Natasha Haskey, a registered dietician who is an expert in gastrointestinal nutrition, especially probiotics and prebiotics, and is now doing her PhD in biology. “They have been in the background of digestive health conversations for years. But now, with the focus on gut microbiota, prebiotics are receiving more attention.”

Haskey notes that prebiotics arrive in the colon intact, where they nourish our good bacteria, and act as “fertilizer” for our gut.

Bacteria in our gut starts to change in our 60s

She and many other dieticians believe all Canadians could benefit from including an ample amount of prebiotics in their diets — none more so than seniors. “We form our gut microbiota in childhood and it remains stable for most of our lives,” Haskey explains. “But when we reach our 60s it starts to change, and we often end up with more [harmful] bacteria in our systems.”

While probiotics can be found in yogurt and other fermented products, prebiotics can be found in beans, legumes, whole grains, and several fruits and vegetables including garlic and chicory root. Artichokes, onions, asparagus, and bananas are particularly good sources of prebiotics and have been the focus of many studies.
It’s difficult to get an adequate number of prebiotics from food alone — 25 raw onions contain just 5 grams of prebiotics in total and we should ingest at least twice that much daily — so many health-conscious Canadians turn to supplements found at pharmacies and health food stores.

“Prebiotics aren’t a magic fix [to improve our health]. They shouldn’t be viewed in isolation,” says Haskey. “But they are definitely one piece of the puzzle.”