Are probiotics helping your IBS? Or, are they expensive supplements that are (literally) being flushed down the toilet?
If you read last week’s post on probiotics, then you know what strains to take for irritable bowel syndrome. This week, I’m going to give you an in-depth explanation on probiotics – who they’re for, the effects of specific strains, and what type to buy. By the end of this post, you’ll be a bacteria guru.
How are probiotic supplements prepared?
All probiotics being prepared for commercial use are done so in single strains or monocultures. Those probiotic blends you see at the store (lactobacillus and bifidobacteria species) are combined far later on in the process.
Some studies have shown that when you prepare probiotic cultures in a laboratory setting, the bacteria are like a “domesticated” version. Meaning that they’re not as robust as the bacterial strains you’d find naturally in your gut. These guys are used to living in the “wild”. the probiotics in our guts have to compete with other organisms for food. This competitive ecosystem makes for a heartier and more robust version of the bacteria. (1)
This translates to the supplemental variety of probiotics being unable to adhere to the walls of your intestines or to be able to express their DNA. Organisms that are unable to adhere to our intestinal walls end up being carried out the digestive tract with the stool. They do not form beneficial colonies in our gut. Thus, having little to no benefit in our GI system.
In order to better prepare lab-grown bacteria for life in the “wild”, some manufacturers have begun stressing the bacteria while in the lab. This includes altering the temperature or the pH in which the bacteria are grown. These subtle stressors have shown to produce bacteria that is more prepared for life in our GI tract. (2)
Once a strain of bacteria has been grown, manufacturers need to preserve these strains. This ensures that when you swallow a probiotic supplement, you’re receiving viable bacteria and not just a pill full of dead bacteria. Freeze-drying is the most common technique used to preserve the bacteria. (3)
Once these single strains of bacteria are frozen, the manufacturer will then mill them into fine powders. It is at this point that manufacturers will combine strains of bacteria in blends that they feel are ideal. This is where you’ll see certain strains of lactobacillus species combined with specific strains of bifidobacteria. (4)
Unfortunately, at the time of this writing, there is no published research that puts specific combinations of probiotic strains up against other strains. Therefore, we’re not entirely sure if one product is legitimately better than another based solely on the combination of bacterial strains used.
Should probiotics be kept in the fridge?
In a word: yes. Probiotics are prone to degradation. Therefore, if they are stored in the fridge, it is likely that their shelf life will be extended. Keep in mind, that the expiration date found on the outside of your probiotic is indicative of when the product would expire should you not open it. Once a probiotic supplement has been opened (thus exposing it to oxygen and moisture) the shelf life is greatly diminished. Meaning, that the expiry date on the bottle is likely well off. In general, probiotics should be consumed within 1-2 months after opening.
Once a probiotic supplement has been opened (thus exposing it to oxygen and moisture) the shelf life is greatly diminished. Meaning, that the expiry date on the bottle is likely well off. In general, probiotics should be consumed within 1-2 months after opening.
Another note on probiotics stored in the fridge: sometimes the fridge environment can contribute to moisture through condensation. refrigeration should not be relied on as a way to extend shelf life. (5)
What bacteria are in probiotic supplements?
There are 5 species of bacteria that are found in the majority of probiotic supplements:
- Lactobacillus species (6)
- Lactobacillus species are commonly found in our mouth, GI tract, and female genitourinary tract
- Most lactobacillus species are found in the stomach and the small intestine.
- There are over 100 different species of lactobacillus bacteria. One of the more popular being lactobacillus acidophilus which is commonly found in commercial yogurts.
- Bifidobacterium species (7)
- Bifidobacterium is a natural resident in our Gi tract as well as the female genitourinary tract.
- Most bifidobacterium species are found in the large intestine and at the end of the small intestine (ileum).
- Bifidobacterium represents up to 35% of all the bacteria found in the adult stool. And, up to 80% of all the bacteria found in infants.
- Next to lactobacillus species, bifidobacterium is some of the most commonly used species in probiotic supplements.
- Streptococcus species (8)
- Streptococci means “twisted berry”. This describes the was strep bacteria grow in chains or pairs.
- Streptococcus bacteria generally reside in the upper part of the GI tract.
- When streptococcus bacteria ferment food, they produce lactic acid.
- Many members of the streptococcus family are pathogenic or bad bacteria. Think, strep throat.
- Saccharomyces boulardii (9, 10)
- S. boulardii is not a bacteria. Instead, it is a beneficial yeast that is found in both our stomach and colon.
- Beneficial yeasts like S. boulardii help protect us from pathogenic (bad) bacteria strains.
- S. boulardii is particularly helpful in treating conditions like clostridium difficile infections and antibiotic-associated diarrhea.
- Bacillus Species (11, 12)
- Bacilli are what are called spore organisms. Think of them as a bacterial seed. Once they are exposed to the right nutrients, the cell will transform to a bacteria cell once again.
- Bacilli species are found in the soil, air, and water.
- Sporeorganismss are more resistant to manufacturing and shipping that may harm many other probiotic organisms.
What is the ideal dose of a probiotic supplement?
Accurate dosing of probiotics can be challenging. Manufacturers differ in the way they quantify the number of bacteria found in each pill. In general, probiotics are measured by a measurement called a colony forming unit or CFU. The CFU is determined by measuring the number of colonies a single cell of the bacteria is able to produce.
When you read the label of your probiotic supplement, you will likely see the number of CFU’s expressed using scientific notation. this is done because the number of cells is so large. 3×10 to the power of 6 would represent 3 million. 3 x10 to the power of 10 would represent 3 billion.
The CFU unit of measurement is inherently problematic. the calculation can only be done for single strains of bacteria. So, when strains are combined (which is done in most supplements) the actual CFU number is an estimate. The manufacturer, unfortunately, does not know how well the strains will colonize when combined with other strains. Additionally, culturing bacteria in a perfect environment found on an agar plate does not convey what the environment inside our digestive tract is like. So, the number of colonies formed on agar may be far greater than the number of colonies formed in our digestive tract. (13)
Additionally, culturing bacteria in the perfect environment found on an agar plate does not convey what the environment inside our digestive tract is like. So, the number of colonies formed on agar may be far greater than the number of colonies formed in our digestive tract. (14)
Unfortunately, at the time of this writing, Health Canada does not place any regulation on how probiotics are labeled nor the minimal number of CFU’s required.
Most supplements on the market contain between 5-25 billion CFUs.
Is a higher dose of probiotics better?
There have been very few studies done that compare high dose probiotics versus normal or low doses of probiotics. At the time of this writing, three studies have been done that compare dosing.
In this particular study, examiners measured the effectiveness of high dose probiotics in the treatment of clostridium difficile associated diarrhea. In this study, higher doses of probiotics reduced the symptoms far more than standard dosing did. (14)
In a different study, examiners assessed how higher doses of probiotics affected the number of bowel movements in a week. This study was done on individuals who averaged 1-3 bowel movements each week. One group was given 1.8 billion CFU (low dose), the other group was given 17.2 billion (high dose) of probiotics. In two weeks, both doses improved transit time though the high dose was slightly better. (15)
In the third study, examiners compared doses of 100 million CFU per day to 100 billion CFU/day in ten-fold increments. Participants of this study tended towards constipation. They noted that as the probiotic dose increased, their stools softened. (16)
As the research on this topic is still incredibly new, we do not have definitive conclusions on what species of probiotics can be dosed at high levels. Nor, for how long that dosing should occur. In general, doses between 200 billion and several trillion CFU/day consisting of mixed strain probiotics should be considered safe for those with irritable bowel syndrome or inflammatory bowel disease. (17) One should pursue this as a short term option – 4-8 weeks or until symptoms improve.
What are the best strains of probiotics?
Well, that will depend on what you are taking the probiotic for. An individual taking a probiotic for general health maintenance will take a lower dose and different strain than one who is having clostridium difficile associated diarrhea.
To date, there have not been studies that compare specific strains of bacteria against another. Becuase of this, we do not have data to quantify which probiotic strains are better than others. (18)
Even though you’ll see many different latin names on the back of supplements, the majority of the organisms are very similar to each other. Lactobacillus acidophilus will produce similar effects to lactobacillus secai. There is no need to worry about choosing the exact strain unless you are trying to remedy a specific disorder.
Your aim should be to promote a diverse colony of bacteria in your digestive tract. This would include using probiotic supplements that contain a diverse mix of different strains. These are called multi-strain probiotics. Additionally, you should consider rotating the probiotic supplement you use every few months.
In last week’s post, I discussed the specific strains of probiotics used for irritable bowel syndrome. If you have a specific bowel condition, ensure that your practitioner is up to date on the latest probiotic research. This way you can ensure your probiotic is targeted to your condition.
When should you take a probiotic supplement?
On an empty stomach?
There’s a lot of debate on when the ideal time to take a probiotic supplement is. While there is not a shortage of opinions on the topic, there’s no research to suggest when the ideal time is. Even in clinical trials, the timing of the dose is not controlled.
There is one study that examined the timing of a probiotic supplement using a living digestive system model. This model was designed to simulate the stomach and small intestine environments. (19)
In this particular study, probiotic survival was improved when the probiotics were taken just before or with oatmeal and 1% milk. The effects were slightly worse when the probiotics were taken 30 minutes after consuming the oatmeal and milk. Though, the improvements would likely not be considered significant. (20)
However, when the probiotics were taken with either water or apple juice, there was a significant decrease in both lactobacillus and bifidobacterium survival. This may be because the fat content found in the milk helped to buffer the stomach acid. Or, it may be because the stomach empties more quickly when there’s just water in it. (21)
As research is still quite spotty on this topic, we recommend you take your probiotic supplement whenever it is convenient. The minimal amount of bacteria lost by not taking your supplement with a meal is likely insignificant when compared to the cumulative effects of daily supplementation.
Ok, now you have all the information needed to be a probiotic guru.
Let me know your favorite probiotic supplements in the comments section below.