No Guts, No Glory- Probiotic Basics

As a dietitian, I often get several clients who request to use probiotics but have no idea what types, brands, strands, etc, they should use. This post will go over what the heck a probiotic is, what are the different types, and the pros and cons of taking them.


Our gut is a magical, lively and vibrant world full of....gut germs, aka bacteria and other microorganisms. These "gut germs" make up a large part of our microbiome, which is unique to each person just like our fingerprints, and play a large part in our immune system, DNA, and our digestive system. According to the Department of Chemistry and Biochemistry at the University of Colorado, "the human microbiota consists of 10-100 trillion symbiotic microbial cells harbored by each person, primarily bacteria in the gut. The human 'microbiome' consists of the genes these cells harbor".1 We are born with a gut fingerprint and it continues to be influenced by our environment and the food we eat. Humans are approximately 99,9% genetically similar, but the microbiome that lives on our hands and gut can vary 80-90%. 1

Poor microbiome health can have a major effect on our bodies causing disorders like leaky gut syndrome, autoimmune diseases like arthritis and dementia, and cardiovascular disease, and cancer. Some researchers believe that up to 90% of all diseases can be linked to our microbiome, aka gut germs. There are various reasons why our microbiome may be off-balance, but most commonly taking antibiotics and other medications can kill bad and good bacteria, throwing the delicate ecosystem of our gut into chaos. These gut germs have a large impact on our digestion, body weight, and metabolism, so it is really important to maintain the health of these little guys!

So how do we maintain the health of our microbiome?

Since our gut acts similar to our skin because it interacts with the outside world via the food and beverages we consume, every time we ingest something we are exposing ourselves to the microbes living on it. So our diet has a huge impact on our overall microbiome health. Studies have shown that our microbiome, once established in early childhood, remains fairly stable throughout our lives. However, outside factors like antibiotics can influence the balance in our gut. We can influence our microbiomes by using probiotics, found in both food and supplements.

The International Scientific Association for Probiotics and Prebiotics defines probiotics as live microorganisms that when administered in adequate amounts, confer a health benefit on the host. 2 Natural sources rich in probiotics include fermented foods like yogurt, kefir, miso, kimchee or sauerkraut. It can be difficult for some to get an adequate amount of probiotics to maintain a healthy microbiome if you do not like fermented foods or just recently underwent antibiotic therapy or are suffering from other gastrointestinal disorders, such as IBS.

There are several probiotic supplements available on the market to help us maintain our gut germ health. What should you look for in a probiotic?

While there are millions if not billions of strands of bacteria, there are two types of bacteria that researchers have studied and one type of yeast:



Saccharomyces boularii

When reading a probiotic supplement, it is important to understand what microbes you are taking. Microbes are listed by genus, species, then strain. 5 Strains are what researchers study so the specific strain used makes all the difference. The other important part to pay attention to is the CFU, colony-forming units, as this is the dose amount and you want to make sure you are ingesting enough.

Here are some strains of probiotics common in the market that have been researched and have clinical studies to support their use:

Bifidobacterium infantis 35624: Can be found in Align. Studies show it can reduce symptoms of Irritable Bowel Syndrome (IBS) such as bloating, cramping and stool frequency. Recommended CFU or dose for Align is 3 capsules per day. 6

Lactobacillus acidophilus CL 1285: Can be found in Bio K+. It has been shown to decrease the incidence of antibiotic associated diarrhea (AAD). The dose recommended is 1 to 2 capsules per day or 1/4 of a bottle per day. 7

Lactobacillus rhamnosusGG ATCC 53103: Can be found in Culturelle. It can reduce the incidence of acute infectious diarrhea and AAD. One to two capsules per day to prevent and treat diarrhea. 8

Saccharomyces boulardii: Can be found in Florastor, a common probiotic prescribed by physicians to treat chronic diarrhea from Clostridium Difficile. Saccharomyces has been shown to be effective at preventing travelers diarrhea and AAD in both children and adults. 8

E coli Nissle 1917: Found in Mutaflor, a potent anti-inflammatory drug used in the remission of ulcerative colitis. A study also showed that it could help those with IBS when taken for 10-11 weeks. It is suggested to take 2 capsules three times a day for the first three days, then 2 capsules two times per day for eight weeks for best results. 8

So are probiotics for you?

Studies show taking probiotic supplements can be helpful in the short term to help improve digestive health. However, if you have a compromised immune system, are undergoing cancer treatment, or are at high risk for infection, you should avoid probiotic supplements, or only take them under the close supervision of a medical professional. There are natural ways to include probiotics into your diet without using expensive supplements. Some examples of probiotic-rich foods are yogurt, kefir, and kimchi. So feel free to make a large bowl of greek yogurt and berries and enjoy!


1. Ursell, L. K., Metcalf, J. L., Parfrey, L. W., & Knight, R. (2012). Defining the Human Microbiome. Nutrition Reviews, 70(1), 1st ser., S38-S44. doi:

2. Hill C, Guarner F, Reid G, et al. The International Scientific Association for Probiotics and Prebiotics consensus statement on the scope and appropriate use of the term probiotic. Nat Rev Gasteroenterol Hepatol. 2014;11(8):506-514.

3. Collins, S. C., MS, RDN, LD. (2014, December). Entering the World of Prebiotics — Are They a Precursor to Good Gut Health? Today's Dietitian, 16(12), 12. doi:

4. Levy, J., CHHC. (2016, January 7). The Human Microbiome: How It Works a Diet for Gut Health. Retrieved October 23, 2018, from

5. Collins, S. C., MS, RDN, LD. (2015, March). Probiotics: Improve Gut Health With Probiotic Supplements. Today's Dietitian, 17(3), 14. doi:

6. Whorwell PJ, Altringer L, Morel J, et al. Efficacy of an encapsulated probiotic Bifidobacterium infantis 35624 in women with irritable bowel syndrome. Am J Gastroenterol. 2006;101(7):1581-1590.

7. Sampalis J, Psaradellis E, Rampakakis E. Efficacy of BIO K+ CL1285 in the reduction of antibiotic-associated diarrhea — a placebo controlled double-blind randomized, multi-center study. Arch Med Sci. 2010;6(1):56-64.

8. World Gastroenterology Organisation. World Gastroenterology Organisation global guidelines: probiotics and prebiotics. Published October 2011. Accessed January 6, 2015.