In this interview with Noah Zimmerman, Verb Biotics CSO, we discuss the role of our gut microbiome in whole-body health, the factors that contribute to a healthy, functioning microbiome, and how science is rediscovering ancestral practices to rewrite the impact of our gut microbiome beyond just digestive health.
Estimated reading time: 8 minutes
Key Takeaways
- The gut microbiome is a dynamic, interconnected microbial community that simultaneously regulates immunity, metabolism, mood, stress, sleep, hormonal balance, and healthy aging — making it one of the body's most influential health systems.
- Gut microbiome resilience, the ability to absorb a challenge and recover, depends on three things: microbial richness (species count), evenness (population balance), and functional redundancy (multiple species sharing the same role).
- 70% of the immune system lives in the gut, where it is continuously trained by resident bacteria — making microbial balance one of the most direct levers for immune health.
- The future of biotic science is not finding one high-performing microbe, it's creating conditions where a diverse, resilient gut ecosystem can thrive. A microbe placed in a depleted environment cannot perform its function, regardless of its individual capability.
- Understanding the microbiome will shift our definition of health towards a personalized and interconnected view of wellness.
In terms of the microbiome's role in health, taking a big-picture view of our gut microbiome, how central is the microbiome to human health?
When we look at the microbiome, the literature shows that it has a central role in our overall health. Now, is it foundational? Probably not.
There's a lot of things that the microbiome does. It's very important in producing some of the metabolites that are going through our body. So, it's very metabolically active. It's producing things like vitamin K and vitamin B. It's producing neurotransmitters, so it definitely has an impact on our health.
It's also regulating things like the immune system. About 70% of the immune system is found in the gut, and it is constantly talking and being trained by the gut microbiome.
Along with that, we know that there are animals like germ-free mice and rats that can live without a microbiome. So, we know that it's not necessarily foundational. But it is probably the central regulator and central modulator for much of our health. Everything that we eat is processed and touched by the gut microbiome, and a lot of the metabolites that are in our body are being produced there.
What I find interesting is that the microbiome changes over time. When we're young, we don't have a very diverse microbiome; it’s dominated by a couple of different genera. At this time, it's making specific metabolites based on the things we ingest, like only eating milk when we're young.
As we get older, it becomes more diverse. Then, as we enter our 60s and 70s, it starts to become less diverse again, and even the metabolic output from our microbiome shifts. That can be good and bad. As a result, as we age, supporting the microbiome through diet and biotics becomes increasingly important.
We often hear that microbial diversity equals better health, what does diversity mean in a microbiome context?
When we're talking about diversity, we're talking about a couple of different things. One is the richness. How many different species are present within a microbiome? And the second is the evenness. How consistently distributed are those, or how abundant are specific taxa compared to others that are in the microbiome as well? When you have a good balance of these things, you tend to have good diversity and good richness. And that allows for redundancy across different functions occurring within the body.
What we aspire to is a nice, diverse, broad ecology or ecosystem within, let's say, our gut. The reason is because that diversity, redundancy and functionality allows for better resilience.
Resilience, to me, is the body’s ability to absorb a challenge and recover. Take a simple example, when you drink water in a city you're visiting that's highly chlorinated, you may impact certain taxa within your gut. But a resilient microbiome has other residents that can step in with similar functions and maintain balance. This is a reminder that the microbiome is much broader than just a couple of different species performing isolated functions. It’s a dynamic, interconnected community able to adapt.
For the most part, when we're talking about something like the gut microbiome, diversity is good, but that's not necessarily true across the board. There are some areas where you don't want to have a diverse microbiome. If we look at the vaginal microbiome in particular, it is actually not diverse at all. This is made up mainly of Lactobacillus and other lactic acid bacteria. When you get increased diversity occurring there, that's actually a bad thing. You need the vaginal microbiome to stay acidic, and it's usually dominated by just four different species of Lactobacillus. Once that becomes more diverse, you can start to get pathogenic organisms that come in there and wreak havoc.
How do microbes actually "work together" within the body, are we looking at ecosystems, networks, or something even more complex?
Picture our gut microbiome as a jungle or rainforest-like environment with foundational organisms. Often, large trees provide fruit and shade and create an ecosystem around them that allows insects to come in and pollinate flowers. Smaller animals and plants are eaten by larger organisms, birds, and those birds are then eaten by larger organisms. Moving up the ladder, you have apex predators as well.
This dynamic is all happening within the gut microbiome. When you remove one or two organisms, you can get something that is imbalanced if you don't have good evenness, good richness, or good diversity, and that can throw the entire system off.
Let’s now transition to the specific workings within the gut microbiome. It's important to look at it as an organ, and it doesn't operate by itself. There is a very strong network of communication that's occurring between organisms within the gut microbiome. You can have taxa like Bacteroides that will break down complex carbohydrates, but they're also messy eaters. And so that leaves a lot of crumbs for other bacteria to come in and feed on. This is great because you get this whole signaling event and these kinds of activity cassettes that are important for stabilizing each other.
We have this milieu of nutrients that's pumping through our gut. Digestive enzymes are at work, and cells in our body are trying to grab what nutrients they can, but they're also releasing nutrients that feed organisms and support a healthy ecosystem for the bacteria as well. Things like mucins and other proteins and carbohydrates that help nourish the right bacteria. So, there is crosstalk not only among the inhabitants of the gut microbiome, but between our cells, our gut, and the microbes that live inside of us. As you can see, it's an ecosystem and a network.
Is the future about finding or developing specific microbes, or about creating the conditions for entire ecosystems to thrive?
I see the future of biotics creating conditions for the microbiome ecosystem to thrive.
Think of this as a well-orchestrated city; construction workers build and maintain the infrastructure, sanitation workers keep it clean, farmers and grocery stores feed everyone. These roles are required for the city to thrive.
The same is true inside our gut. If you put high-functioning microbes in an environment with nothing to interact with, they won't be able to perform their role.
Building a well-orchestrated, diverse, and resilient microbiome community, utilizing each member to the fullest, is really what's going to help us thrive and become healthier.
We've heard about indigenous cultures having very rich microbiomes. In what way is science just beginning to rediscover what ancestral practices might have already understood?
Much of what has worked in ancestral cultures wasn’t the result of controlled experiments, they happened upon through experience. Experiential knowledge passed on through generations and refined through validated practices that built remarkably diverse microbiomes.
On the other hand, science traditionally took a different path. The view has been to isolate; break the process into parts, study in controlled settings, and draw conclusions. We analyze how one nutrient may be important toward a specific health outcome and study it by itself. Yet, down the road we find that the nutrient doesn't work quite perform as well as it does in its natural environment. An example of this is vitamin C which is great for your immune system. We’ve found that you need other nutrients to absorb vitamin C and be able to use it effectively within your body.
Now science and ancestral wisdom are converging; that our microbiome is an interconnected ecosystem.
Once we fully understand the role and composition of our microbiome, how might it impact our definition of "health"?
Currently, our health care system is set up to make us not be sick, but this is not the same thing as maintaining health and vibrance, this distinction matters.
As we start to understand the true interconnectedness of everything that's happening within our bodies, we start to see that health itself is a network.
And this network is unique to each of us. Your microbiome, your microbial community, your genetics are not the same as mine, yet they share the same genes and need metabolites and end products to function well.
We’re seeing the shift now, health no longer becomes what is broken, but what is the right balance for you at this specific point in your life.
Health will become more personalized where each human body will be viewed as a multi-species organism that has the person sitting on the outside and all these different microbes and other engines of possibility that are living within our guts or living on our body, in our hair, on our skin. This living network of species, interconnected view will enable us to obtain a better understanding of what each body needs for long-term health.
About Noah Zimmerman, Ph.D.
Noah has over 25 years of experience in science and technology, specializing in microbiome health. Prior to Verb, Noah was awarded an Innovation Grant from the U.S. National Institute of Health and helped to co-found Agro BioSciences Inc., where he was the Director of Research. He later led the Biochemistry, Immunology, and Human Probiotics Platforms at Church & Dwight Co. Inc. Noah has a proven track record of probiotic innovation and is actively patenting the use of multiple probiotic strains for various health benefits.
Noah earned his Ph.D. and M.S. from the University of Wisconsin, with an emphasis in Disease Physiology.