top of page

Probiotics, prebiotics and postbiotics: what are they and are they effective?

Updated: Oct 31, 2023

In the world of gut health, probiotics are one of the first supplements that pops into people’s minds. But, are they helpful?

Probiotics are cultured bacteria that are consumed with the intention of helping gastrointestinal function.

When we talk about the microbiome in functional medicine, the diversity of microbial species in the gut is essential. Studies have shown that traditional hunter-gathers have a much higher level of diversity in their microbiome profiles compared to people living in urban areas.

But, if we can’t ditch our day jobs and start hunting and foraging again, then what do we do?

Well, the answer is NOT probiotics.

Myth: Probiotic recolonize the microbiome to help restore balance. FALSE.

Unfortunately this is not the case. You don’t take a capsule of lactobacillus and then end up with an intestinal flora that has a higher concentration of lactobacilli. This would make my job much easier, but it just isn’t the case.

Truths about Probiotics:

  1. They crowd out pathogenic bacteria. While they do not recolonize the gut, they can potentially crowd out bad bacteria that may cause harm to our gut ecosystem. This can help prevent the overgrowth of bad guys, which can happen in things like small intestinal bacterial or fungal overgrowth (SIBO/SIFO).

  2. They are transient guests. Think of probiotics as place holders. As they travel through the intestines they are place holders that take up space and relay messages to other bacteria and to our nervous system. They are just tourists though, they don’t take up residence. They are consumed, and pooped out, just like your food.

  3. They can be anti-inflammatory. Some strains of probiotics like F. prausnitzii can help to inhibit NFkB, a transcription factor that is responsible for the production of pro-inflammatory compounds. NFkB has been associated with several inflammatory conditions like inflammatory bowel disease, asthma, atherosclerosis, and psoriasis.

So are probiotics bad for you? Absolutely not, they can be helpful in certain conditions like ulcerative colitis, and maybe IBS.

Fecal microbiota transplantation is one of the few therapies that change the gut microbiome. To learn more about fecal transplants check out Dr. Mary’s blog on FMT here.

Prebiotics: prebiotics are food for our microbes. Some examples of prebiotics are soluble and insoluble fibers from fruits and vegetables. Polyphenols are also prebiotics, they feed our bacterial to ensure a healthy microbiome. Polyphenols from fruits and vegetables are those molecules that protect our cells and make our veggies and fruits bright colors. Anthocyanin, and tannins are two examples of polyphenols.

Foods loaded with polyphenols:

  • Cocoa powder

  • Cloves

  • Oregano

  • Celery seed

  • Dark chocolate.

  • Flaxseed meal

  • Black elderberry

  • Berries

Post-biotics: Post-biotics are compounds that our microbiome produce. Yup, those little creatures are there for a reason! They produce anti-inflammatory short chain fatty acids that have many key roles in gut health.

Short chain fatty acids (SCFAs):

  • Regulate gut motility (so you have 1-3 healthy poops per day)

  • They are fuel sources for your intestinal cells, giving your gut energy to work properly

  • Are anti-neoplastic, meaning they help protect against cancer

  • They support our TReg cells which balance our immune system

Now, you are probably thinking, "How do I get more SCFAs in my life?"

Welp, it’s pretty simple, eat more vegetables! Check out modrn's Food Strategy Guide and learn how to optimize your pre and post biotics.

To learn about how the Network of Care at MODRN can help you achieve your gut health goals, become a patient today!


PMID: 11134171

PMID: 24736369

2,191 views0 comments


bottom of page