Garlic is just one source of prebiotic. Photo: Flickr/Creative Commons, jurek d.

Most people have heard about probiotics. But do you know about prebiotics, which feed this good microbes or bacteria in our large intestine? According to dietitians, you should. Prebiotics don’t just help with the benefits we expect from fibre, like reducing diarrhea and constipation. They also contribute to a range of other health benefits. Unfortunately, most of us take less than half of what we should. 

“Research suggests we consume one to four grams [of prebiotics] per day, but we should aim for at least 10 grams per day,” says Natasha Haskey, a dietitian who is a researcher in gut health, based in Kelowna, BC. “Even eating 25 raw onions would only give you about five grams of prebiotic fibre.”

“Experts are now calling our gut an organ system,” she says. “Up to 80 percent of our immune system resides in our gut so clearly the gut is important to immunity.”

There is plenty of evidence of the benefits of prebiotics on our health, says Haskey. “Experts are now calling our gut an organ system,” she says. “Up to 80 percent of our immune system resides in our gut so clearly the gut is important to immunity.”

How prebiotics work
Prebiotics are a fibre, but not all fibre is prebiotic. Prebiotic fibre will resist digestion in the stomach and upper part of our intestine, and reach the large intestine where it is fermented by the good bacteria. The byproducts of this fermentation, called short chain fatty acids (SCFA), not only feed the good bacteria but are responsible for health benefits.

SCFA are known to keep the gut healthy, reduce inflammation, prevent colon cancer, help with satiety, improve heart health, enhance the absorption of calcium, and even help to maintain blood glucose level, says Haskey. As well, there is even some evidence that prebiotics can help with emotional well-being.

Watermelon is a good source of prebiotic fibre. Photo: Flickr/Creative Commons, Ron Doke.

How can we get more prebiotic fibre?
There are a range of good food sources of prebiotic fibre. These include watermelon, chicory root, leeks, onions, garlic, asparagus, dandelion greens, fennel, cabbage, radicchio, pistachios and artichokes.

A male hunter in prehistoric times would consume almost 130 grams of fibre daily from plants found in the desert that are rich in prebiotic fibers such as agave, prickly pear and wild onion. And studies of people living in primitive villages showed that they would consume up to 40 grams of fibre a day, of which most is prebiotic, without the same digestive conditions we have, she says. It can be challenging to get an adequate amount of prebiotics in our current diet.

Supplements
Supplements are one way to get the daily levels we need. One option is Fibre Choice, a prebiotic supplement containing the key ingredient, inulin. Fibre Choice is available as a chewable, fruit-flavoured tablets. It is available in different formats as FC assorted fruits, which contain two grams of inulin, and as Fibre Choice for bone health, which contains calcium and vitamin D as well as inulin.

A recent peer-reviewed clinical study of Fibre Choice found a statistically significant increase in stool frequency in inulin users compared to placebo users, and higher patient satisfaction, due to more frequent and softer bowel movements. They also found it to be generally well tolerated.

Consult a dietitian first to find out how much fibre, and prebiotic fibre specifically, is best for you. And when you increase your fibre intake, start gradually to avoid digestive upset and drink plenty of water.

Fibre ensures that waste moves through the digestive tract smoothly and efficiently. Photo: Flickr/Creative Commons, Paula Whidden.

Why now?
Prebiotics are essential throughout our lives, but particularly as we get older.

“As we age, it is even more important to feed the good bacteria in our gut. We start taking more medications, our digestion changes and our diets may change, which influence bacteria in the digestive tract and not necessarily in a positive way,” says Haskey.

The recommended dose of fibre per day is much higher in men than women. Health Canada recommends 25 grams of fibre per day for women and 38 for men. We don’t have the same information about gender differences for intake of prebiotics. But what we do know is that men and women aren’t getting enough and we all need to be proactive.