The gut of the matter: The truth about probiotics

Not sure if you should be taking a probiotic? What about a prebiotic? We're breaking down the good and bad (bacteria, that is) about gut health.

The gut of the matter: The truth about probiotics

Not sure if you should be taking a probiotic? What about a prebiotic? We're breaking down the good and bad (bacteria, that is) about gut health.
Truth about probiotics

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Can’t tell your probiotics from your prebiotics? We’re here to help. 

Don’t get too grossed out, but there are about 100 trillion bacteria living inside your digestive system right now.

But before you panic, that statement does come with an asterisk: the bacteria we’re referring to is the good kind. It makes up what’s called your gut microbiota and it’s essential for well-being.

Everyone’s gut microbiota is unique (with about 1,000 different species of gut bacteria and some 5,000 distinct bacterial strains), but there are certain combinations and collections of bacteria that healthy people all have in common.

Probiotics, in the simplest terms, help support your gut health.

They contain many of these same combinations of bacteria because, as we’ll explain, there’s a lot going on in your gut and you might need a little help maintaining balance. 


The key to a healthy gut is keeping the peace between the good and bad bacteria.

There are a number of different factors that affect the health of your gut bacteria, including stress, age, and diet. But perhaps one of the most well-known culprits is antibiotic usage.

In addition to fighting off whatever virus you have, antibiotics can also kill off the healthy bacteria in your digestive system. That leads to an imbalance known as dysbiosis, where the bad bacteria far outweigh the good bacteria.

When that happens you might notice gastrointestinal symptoms like diarrhea, constipation, bloating and heartburn. You may also crave sweets and sugary foods if there’s an overgrowth of yeast in your gut. (So that explains everything.)

Your gut health is also closely linked with your mental health thanks to the vagus nerve, a two-way pathway that allows the gut and the brain to communicate. Some even refer to the gut as the “second brain.” 

Your body’s natural serotonin, commonly known as the happy chemical, is primarily found in the gut — not the brain, as you might assume. Another neurotransmitter called GABA is also often present in the gut.

Both GABA and serotonin are released from good bacteria in the gut so you can see how an imbalance in bacteria might affect your mood. Most recently, scientists started studying the role that the gut microbiotia might play when it comes to dementia, autism and other disorders.


The connection between fermented foods, bacteria and health technically originated with the discipline of microbiology, but it wasn’t until the early 20th century that research really began to pick up.

In 1930, a Japanese microbiologist named Minoru Shirt first discovered bacterial flora that survived passage through the gut after ingestion. He was able to isolate and cultivate what became known as Lactobacillus casei strain Shirota (LcS)and this actually led to the first fermented bacteria-containing drink in 1935. 

But the term probioticwasn’t used until 1953.

It’s derived from Latin (pro) and Greek (bios) meaning “for life.” The definition has changed a bit over the years and our current definition, drafted by the FAO/WHO in 2001, defines probiotics as “live microorganisms which, when administered in adequate amount, confers health benefit to the host.”


By taking a probiotic, you’re essentially adding back the “good” bacteria that your gut is missing. This helps balance the “good” and “bad” bacteria so your body continues working the way it should. 

There are so many different varieties and combinations of probiotics but they all consist of live organisms similar to what you’d find naturally in your intestines. These live microorganisms can be found naturally in some foods (like yogurt and kimchi) as well as pill, powder or other forms of probiotics.

The most common probiotics are Lactobacillus (which supports digestion and immune function, and may also reduce anxiety), Bifidobacterium (which helps digest fibre, supports metabolic processes and improves brain function), and Saccharomyces (which is actually a “friendly yeast” that’s antibacterial and aids in preventing disease and supporting skin health).

There are *almost* as many benefits of probiotics as there are probiotic strains (Not really but there are a lot, OK?)

Here are just a few examples of what they can help with:

• If you want to keep your gut healthy, look for a probiotic with 50 to 100 billion CFUs of lactobacillus and bifidobacterium.

• If you’re having tummy troubles (think bloating and constipation), look for lactobacillus acidophilus or lactobacillus casei which help to restore gut flora. If you have diarrhea, you’ll want saccharomyces.

• If you need a mental health boost, research shows that lactobacillus planetarium and bifidobacterium bi-fi0dum are two strains that help with anxiety.

• If you’re prone to bacterial vaginosis or yeast infections, you’ll want a female-specific probiotic with multiple lactobacilli strains. A probiotic suppository is probably the best option here as it’s the most direct way to “recolonize” your vagina with good bacteria. (Yes, we giggled, too.)

Clearly, these live organisms are pretty important for your health.

But every superhero needs a sidekick and probiotics are no different.

Enter prebiotics.


In 2002, the FAO/WHO drafted additional guidelines regarding the evaluation of probiotics in various food products. Prebiotics are defined as “indigestible food ingredients that selectively promote the growth or activity of beneficial bacteria, thereby benefitting the host.”

Since probiotics are actually living organisms, they need to feed on something to survive, right? That’s where prebiotics come in. Prebiotics are typically high-fibre foods that act as food for our microflora. 

Prebiotics are found naturally in foods such as whole grains, bananas, greens, onions, garlic, soybeans and artichokes. And, like probiotics, they’re also available in supplement form.

But that’s not all: Synbiotics are supplements that contain probiotic strains in addition to prebiotics. Some researchers say the combination of the two might help probiotics actually make it to the gut. In some cases, your stomach acid might destroy the probiotic before it reaches your intestines. Taking a supplement that’s in a coated capsule (known as the delivery method) can help protect the bacteria as it makes its way through your system. 


As we mentioned, you can get some probiotics from foods but probiotic supplements typically provide a much higher dose, as well as a diversity of strains.

— SHOP —

Seed Female Daily Synbiotic, $65 for a 30-day supply.
Flora VagiCare Probiotic, $31.99 for 10 at
Genuine Health Probiotic Gut Health 50 Billion, $36.99 for 30 at Healthy Planet
Jamieson 30 Billion Probiotic, $29.97 for 30 at Walmart


Was that a lot to digest? Well, there’s more. Probiotics need to be taken consistently (a.k.a. every day) in order for them to be effective.

If you think about it, you’re losing bacteria every day — in the form of, ahem, poop — and other factors (think daily stress, illness, etc.) can also alter the microbiome within days. 

Unless your daily diet is perfect (and even then, there’s no guarantee it’s affecting your gut the way you think it is), you can probably benefit from a pro (and pre, for that matter) biotic. 

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