how to choose a probiotic
Do you need a probiotic?
Which one is right for me?
If it makes me more bloated should I stop taking them?
With so many probiotics on the market, it can be overwhelming trying to choose.
Instead of randomly guessing which one might work for you, it’s important to do your research to find the right product.
Why Probiotics Matter for Gut Health
Probiotics are live microorganisms — mainly beneficial bacteria and yeast — that help keep your digestive system healthy. They’re often called “good bacteria” because they support balance in your gut microbiome.
What Are Probiotics and How Do They Work?
Your gut naturally contains trillions of microbes — bacteria, yeast, and even viruses — that together make up the gut microbiome. When this community is balanced, it plays a huge role in:
Digesting food & absorbing nutrients
Supporting the immune system
Producing vitamins and neurotransmitters (like serotonin, the “feel-good” chemical)
Protecting against harmful microbes
You already have probiotics living inside you — your body depends on them.
Probiotics as Supplements
While the gut has its own natural probiotics, sometimes diet, stress, antibiotics, or illness can throw things off balance.
That’s where probiotic supplements come in. They provide extra doses of beneficial strains (like Lactobacillus, Bifidobacterium, Saccharomyces boulardii, or spore-based probiotics) to help restore balance.
However, probiotics cannot stay alive in your gut longer than about 6 to 8 weeks after you stop taking them.
This is why they are used as a temporary tool, rather than a long term solution. The long term game plan is to grow your own healthy permanent bacteria by increasing your prebiotic fibre and antioxidant intake and calming inflammation in the gut.
How PROBIOTICS Can Help
Supplementing with the right probiotics may support:
Digestive health → reducing bloating, gas, constipation, or diarrhea
Stronger immunity → fewer colds or infections
Mood & brain health → thanks to the gut-brain connection
Hormone balance & metabolism → through reduced inflammation and better nutrient absorption
How do I know if I need a probiotic?
-The Link Between Probiotics, Digestion, and Immunity
You may need a probiotic if:
you have recently used an antibiotic
you have chronic diarrhea or constipation
you are prone to getting sick
you have chronic inflammation such as pain, migraines or high inflammatory markers on blood work such as CRP.
you have IBS and/or gut microbiome imbalances: especially if you have had a stool test and tested low for specific healthy gut bacteria strains
you are prone to recurrent vaginal infections such as bacterial vaginosis and/or yeast infections
How do I know what’s going on in my gut microbiome?
When I work with clients I use a functional stool tests: the GI MAP and GI 360. These tests use advanced PCR analysis of a stool sample to sequence your gut microbiome and provide a comprehensive report that tells me:
To determine the balance of bacteria in the gut, advanced stool tests are used to sequence the species of microbes present in the gut microbiome.
The patient submits a stool sample and it’s processed using PCR analysis, then a comprehensive report is supplied. The report indicates levels of healthy and less desirable bacteria, yeasts, viruses and parasites and also indicates:
Markers of inflammation (calprotectin and occult blood)
Absorption & fat digestion (steatocrit (fecal fat) and pancreatic elastase)
Immune function in the gut (IgA, anti-gliadin and Eosinophil Activation Protein)
Gluten reactivity (anti-gliadin IgA)
Estrogen metabolism (B-glucuronidase)
The stool tests also tell me which type of gut imbalance you have an how to treat it.
This includes:
insufficiency dysbiosis: low levels of healthy gut bacteria including keystone species such as Akkermansia muciniphila and Faecalibacterium prausnitzii
infections and dysbiotic overgrowth: harmful species such as Klebsiella pneumoniae, Citrobacter, C. difficile, M. avium subsp. paratuberculosis
IMO: intestinal methanogen overgrowth
Hydrogen sulfide overgrowth: Desulfovibrio
H. pylori: the bacteria that causes ulcers and gastritis
Parasites: Giardia, Blastocystis hominis and a variety of worms
Yeast overgrowth: Candida
Viruses: Epstein-Barr, Cytomegalovirus
How to Choose a Probiotic Supplement
Determining which probiotic is best for you can be difficult, and taking the wrong probiotic can actually make you feel worse - more bloating, gas and heartburn, or even diarrhea.
This is why I encourage everyone to work with a practitioner to get a personalized probiotic prescription, as there are many types on the market and they do very specific things for the body.
In general, there are 4 main classes of probiotics:
Lactobacillus species: there are many but common strains include L. platarum, L. acidophilus, L. acidophilus, L. casei
Bifidobacterium species: common strains include B. longum, B. infantis, B. bifidum, B. lactis
Probiotic yeasts: S. Boulardii
Spore based probiotics: Bacillus coagulans, Bacillus clausii, Bacillus subtilis.
There are now also bacteriophages (viruses that invade and kill bacteria) being used in some probiotic formulas, although they’re not yet available in Canada.
Best Probiotic Strains for Gut Health
The strains are the different types of bacteria that are in the probiotic. There are many different strains of each particular type of bacteria, for example, Lactobacillus plantarum have several strains ont he market, each one is denoted by the number that comes after it, for example:
For people with chronic heartburn, acid reflux and GERD or SIBO (small intestine bacterial overgrowth), the best strains are spore based (bacillus coagulans, bacillus clausii, bacillus subtilis), as well as the probiotic yeast S. Boulardii.
There is a lot of ongoing research into which strain is best for which gut health condition, however, everyone’s gut and body is unique, which is why I always personalize probiotic prescriptions for clients.
Probiotics for Constipation vs. Diarrhea
Some of the most well-researched strains include:
L. acidophilus NCFM: reduce diarrhea and immune support.
L. plantarum WCFS1: immune support, heals leaky gut and anti-inflammatory.
L. plantarum 299v: improves iron absorption, supports mood, immunity and leaky gut repair
L. rhamnosus GG: bowel regularity and immunity/allergies, reduce anxiety, GR-1 and Lcr35 support vaginal health
L. casei 19438: constipation and infant gut health
L. helveticus: supports mood, reduces anxiety and depression symptoms
L. reuteri: helps prevent infections, may reduce hot flashes
S. boulardii: reduces chronic diarrhea and infectious diarrhea
Bacillus coagulans: for constipation, IBS symptoms such as gas, bloating and pain, supports immune function, supports recovery for athletes, oral health, vaginal health
Understanding CFU Dose—How Much Do You Really Need?
More is not necessarily better. Probiotics are measured in CFUs - colony forming units and products range anywhere from 100 million to 100 billion.
Most people only need a lower dose, targeted probiotic. The only people that may need higher dose probiotics are those that have recently taken antibiotics or are very sick and fighting an illness or infection. High doses are often recommended for IBD (inflammatory bowel disease) as well. If your body doesn’t need a higher dose, it may cause excessive gas and bloating or belching and indigestion.
Prebiotic content: many products, especially those that are shelf stable contain prebiotic fibre to feed the healthy bacteria and help it survive. This is beneficial, but for some people with sensitive guts and significant dysbiosis, prebiotic fibre may cause a lot of gas, bloating, pain and even diarrhea.
Factors to Look For in a Quality Probiotic
Shelf-Stable vs. Refrigerated Probiotics
Probiotics don’t need to be kept in the fridge to stay alive: as long as they have a food source (typically they add a prebiotic fibre or sugar), they will stay alive on the shelf until the expiry date. They do this by adding more than the dose on the label that will slowly die off as the product ages, and that way they can guarantee a minimum dose on the label up to the expiry date.
It depends on the reason you’re taking the probiotic. For example, new research has proven that even “dead” probiotics that have been heat killed still have a benefit on the person, including immune support and anti-inflammatory effects.
Multi-Strain vs. Single-Strain Formulas
When choosing a probiotic supplement, one important factor is whether it contains a single strain or a multi-strain formula.
A single-strain probiotic focuses on delivering a very specific benefit—for example, Saccharomyces boulardii is often used to support diarrhea and gut infections, while Lactobacillus rhamnosus GG is well-researched for immune support.
Multi-strain probiotics, on the other hand, combine different types of bacteria (and sometimes yeast) to provide broader digestive and immune benefits, since each strain plays a unique role in the microbiome.
While single-strain formulas can be effective for targeted gut health concerns, most people benefit from a well-designed multi-strain probiotic that mimics the natural diversity of the gut.
Multi-Strain Probiotics
Provide broader gut health benefits by combining different strains
Mimic the natural diversity of the microbiome
May support digestion, immunity, and inflammation all at once
Often better for general gut health maintenance
Single-Strain Probiotics
Deliver targeted benefits for specific gut issues
Easier to study in research because only one strain is used
Helpful for short-term concerns like antibiotic recovery or traveler’s diarrhea
May be ideal if you’re working with a practitioner on a specific gut imbalance
My review of common probiotic brands:
Seed probiotic: while Seed’s probiotic profile is impressive in their variety of strains and species, an all-in-one probiotic like this isn’t always well tolerated. I always prefer to use more targeted strains, depending on your personal gut profile.
Align probiotic: many clients have told me that Align probiotic either doesn’t help them, or made them feel worse, however, it is well researched to be effective for IBS. The active strain is Bifidobacterium longum subsp.longum 35624TM. It can help ease IBS symptoms and reduce inflammation in the gut.
Florastor probiotic: this is a probiotic yeast called S. boulardii that is clinically proven to help reduce diarrhea, so it may be helpful if chronic diarrhea is your main concern. For people who are prone to constipation, it may be best to avoid this strain.
Probiotic Side Effects Like Bloating: What They Mean
This is a common issue I see with clients - either a probiotic make them feel worse, or it didn’t help their symptoms at all.
It can be for one of four reasons:
It’s not the right strain for your gut
They took the probiotic for only a few weeks, then stopped.
They didn’t change their diet at all/are on a diet low in prebiotic fibre. Prebiotic fibre is needed to feed the probiotic sand keep them alive longer in the gut. It also helps you grow your own healthy, permanent bacteria.
There are other deeper reasons for your gut symptoms. This can include:
food sensitivities
chronic stress
mental health concerns: anxiety, depression
poor sleep
inflammatory diet
medications: especially painkillers, antibiotics, GLP-1 agonists, Ozempic
other disease processes: Hashimoto’s, IBD, diabetes/blood sugar imbalances and others.
When to Seek Professional Guidance
If you’re struggling with chronic digestive issues and probiotics aren’t helping, I’m here to support you. Let’s take a deeper dive together and find out what’s really going on so you can get back to feeling lighter and enjoying the foods you love!
Limited appointments available for Fall 2025 - book yours by clicking below.
