A GI Physician’s Top 4 Tips for Choosing a Quality Probiotic

Zain Kassam, M.D., M.P.H. is a pioneer in the microbiome space. Trained as a gastroenterologist, he has authored over 200 peer-reviewed publications and abstracts and helped successfully translate microbiome science into real-world, scalable solutions like public stool banks and standardized fecal microbiota transplantation (FMT) protocols.

Seed is honored to have him as our Chief Medical Officer. Needless to say, when Dr. Kassam talks, we listen. And when he shared his top protocols for determining probiotic efficacy, you can bet we took diligent notes. Here are the four “D’s” of his approach to analyzing a probiotic:

The Seed Digest:

• The most effective probiotics for broad-spectrum benefits offer a diverse array of strains, utilize targeted delivery, include prebiotics to fuel microbial growth and function, and are backed by rigorous testing.
• Many products on the market fall short in at least one of these areas. They don’t survive digestion, lack microbial diversity, or make unsupported claims about their formulas. 
• Formulated with 24 diverse strains, a reliable ViaCap® delivery system, and a potent prebiotic from Indian pomegranate, DS-01® Daily Synbiotic is different. The synbiotic has been validated across four randomized, double-blind, placebo-controlled trials for gut and whole-body health outcomes.*

1. Diversity

Diverse environments tend to be more resilient. This is true whether you’re talking about a forest, a backyard garden, or the wonderfully wild landscape of the gut. Diversity ensures that if one species is lost or disrupted, others can step in to fill its role.

In the gut microbiome, Dr. Kassam explains, having a diverse array of bacterial strains is vital for resistance against pathogens, and loss of microbial diversity (dysbiosis) can be associated with compromised immunity.^1,2 Most probiotics are only formulated with a handful of bacterial strains, affecting their functionality and resilience.

It’s also worth noting that within each species of bacteria, there can be hundreds or even thousands of specific strains, each with its own effects. Some probiotic companies only disclose the species they use and not the strains, leaving customers without a key piece of information.

The Seed Difference:

DS-01® Daily Synbiotic is formulated with, count ‘em, 24 different strains of bacteria that you won’t commonly find in yogurt or fermented foods and drinks. 

These bacteria span a wide genomic diversity (35,000 unique microbial genes) and include strains that have been scientifically shown to promote a range of whole body benefits, from easing bloating and intermittent constipation to promoting gut barrier integrity and a strong immune system.*^3,4,5

EXPLORE FURTHER: So, You Just Started DS-01®. Now What?

This is one reason why many people who take DS-01^® notice a variety of positive changes (beyond gut health). “When I take the Seed probiotic, I can tell that it’s working. I can feel it. My skin feels better. I don’t feel bloated. I am going more regularly. The other probiotic that I was on, I didn’t experience that,” says one Seed member, George.*

“Now that I’m on  DS-01^®, I feel so light,” says Seed member, Megan. “I feel like I have more energy… I’m able to go do all the things that I want to do.”*

2. Delivery

Imagine you’ve just mailed a birthday package to your best friend, filled with a heartfelt note and a gift you’re sure they’re going to love. But the post office delivers it to the wrong address, and your friend never gets it. 

That’s basically what goes down when a probiotic isn’t properly formulated to withstand the journey through your digestive tract. Even the best strains aren’t worth much if they don’t get where they’re supposed to go, Dr. Kassam explains. 

As live organisms, probiotic bacteria are sensitive to factors like heat, oxygen, light, and moisture. En route to your colon, these good bugs must travel through your stomach: a highly acidic environment that kills most microorganisms. Some research shows that just 20–40% of probiotic bacteria survive the journey, depending on the strain, delivery method, etc.⁶

The Seed Difference:

DS-01® is designed to ensure it makes it to its final destination intact. Its unique delivery system, the ViaCap®, contains an outer capsule that protects against oxygen, moisture, heat, and acidity to keep the microbial matter inside safe from disruptions. This outer capsule begins to dissolve once it makes it through the stomach and into the small intestine, transporting bacterial strains to the colon, where most of your gut microbiota reside.

EXPLORE FURTHER: Following the Journey of Your Food: From Eating to Excreting

Using a fermentation model that simulates all the compartments of the GI tract (SHIME®), we’ve demonstrated that the ViaCap® is able to withstand the harsh conditions of the stomach and protect the probiotic organisms on the way to their target site, ensuring a smooth delivery for your precious cargo. 

3. Do-Gooders

Prebiotics are non-living substrates that nourish gut bacteria and allow them to grow and thrive. These prebiotics—or “do-gooders” as Dr. Kassam calls them for the sake of this mnemonic—feed probiotics so they can do their job effectively. In the process of digesting prebiotics, probiotics also produce secondary compounds like short-chain fatty acids, which have whole-body benefits of their own (stimulating the production of dopamine, supporting a healthy inflammatory response, and promoting a strong gut barrier, to name a few.)^7,8,9,10 

EXPLORE FURTHER: Prebiotics 101

In essence, taking a probiotic that doesn’t contain a prebiotic is a bit like using a phone without a charger. There’s no guarantee it will have power when you need it most. 

The Seed Difference:

DS-01^® is a symbiotic; a combination of probiotic bacteria and prebiotic substrates derived from the fruit and skin of Indian pomegranate.*¹¹

4. Data

Unlike pharmaceuticals, probiotic supplements don’t need to be rigorously tested on humans before they hit the market. This creates a fast track for rapid innovation and development, but it also opens the door for some products that are built on shaky (or non-existent) science.

As Dr. Kassam explains, “Most probiotic companies don’t do clinical trials and they very rarely interrogate the deep biology of why a probiotic works.” As of 2024, only about 16.7% of the 100,000+ supplements on the market had undergone clinical trials.^12,13

Instead, companies will make claims based on studies that have previously been conducted on the individual strains in their product. This is less than ideal for a few reasons. For starters, there’s no guarantee that these studies were conducted in humans. They could have been done on animals or cell cultures. Second, strain-level testing is not indicative of how a product works on the whole. There’s the possibility that its ingredients won’t confer the same benefits when combined, or that their impacts will differ from person to person.

The Seed Difference:

If other companies study their products under a magnifying glass, we look at ours using the equivalent of the world’s best microscope. We conduct deep genomic sequencing, randomized controlled trials, and detailed safety testing on  DS-01^®. And we’re committed to continuing to test the product against new claims, so we can say with certainty what it is and isn’t scientifically validated to do.

EXPLORE FURTHER: How Seed Is Setting a New Standard for Probiotics Research

So far, we’ve conducted four randomized, double-blind, placebo-controlled trials on  DS-01^® in humans, demonstrating how the synbiotic impacts a wide range of health metrics, down to deep biomarkers like urolithin A and butyrate. This testing has revealed that DS-01^®: 

• Supports comfortable and regular bowel movements in people who experience occasional digestive discomforts.*¹⁴
• Promotes gastrointestinal resilience and supports healthy gut barrier function following temporary disruptors.*⁴
• Increases the production of butyrate (a key short-chain fatty acid for immunity and metabolic health) in individuals with low baseline butyrate levels.*
• Increases the production of urolithin A—a metabolite that supports cellular repair and regulates key biological processes associated with longevity.*

The Key Insight

Every time you read about the “trendy” new probiotic to hit the market, remember the four D’s: Diversity, Delivery, Do-Gooders, and Data. We formulated DS-01® Daily Synbiotic to tick off all of these boxes and then some. The result is a clinically validated, scientifically grounded, and intentionally designed synbiotic that delivers real impacts people don’t want to go without. 

“I can’t see a time when I won’t be taking DS-01®, at least for the foreseeable future,” says Seed member Melissa. “Experiencing the benefits that it’s offered my body has really been life-changing.”