Have you ever had a “gut feeling”?
A sense that something was off before you could explain why.
Butterflies before a big decision.
Nausea during stress.
A knot in your stomach after difficult news.
We use these expressions every day because instinctively, we know the gut and the brain are deeply connected.
And science confirms it.
Your gut is not simply a digestive tube.
It is an intelligent communication network.
Home to trillions of microbes.
A large portion of your immune system.
And an extensive neural network often referred to as the enteric nervous system.
In many ways, your gut is constantly sensing and responding to the world around you.
What you eat.
How you sleep.
How you think.
How you move.
How stressed you are.
Whether your body feels safe.
The microbiome — the collection of bacteria, fungi, and other organisms that live primarily in the large intestine — plays a remarkable role in overall health.
These organisms help:
• break down food
• produce short-chain fatty acids such as butyrate
• synthesize certain vitamins, including vitamin K and several B vitamins
• regulate inflammation
• support the intestinal lining
• influence hormones
• communicate with the brain
Butyrate, in particular, serves as a primary fuel source for the cells lining the colon and helps maintain the integrity of the gut barrier.
When this barrier becomes disrupted, inflammatory compounds and partially digested food particles may interact more directly with the immune system, contributing to symptoms far beyond the digestive tract.
In fact, the gut is involved in the production and regulation of many important signaling molecules.
Approximately 90% of the body’s serotonin is produced in the gastrointestinal tract.
While this serotonin does not directly cross into the brain, it plays a critical role in regulating motility, signaling, and communication along the gut-brain axis.
This helps explain why digestive health can influence:
• mood
• cravings
• sleep
• energy
• immune function
• skin health
• mental clarity
The gut is not separate from the rest of you.
It is central to how you feel.
When the microbiome is thriving, we often feel it.
Digestion becomes smoother.
Energy feels steadier.
Cravings decrease.
Skin may improve.
Mood feels more resilient.
When it’s disrupted, the signals can be more subtle.
Bloating.
Constipation.
Loose stools.
Brain fog.
Fatigue.
Food sensitivities.
Increased inflammation.
The body has many ways of telling us something is out of balance.
One of the most fascinating aspects of the microbiome is how responsive it is.
Your microbial ecosystem can shift within days in response to:
• dietary changes
• sleep quality
• medications, especially antibiotics
• stress
• travel
• exercise
• alcohol intake
• time spent in nature
This is both humbling and hopeful.
Your body is dynamic.
And small, consistent choices matter.
A 2025 study published in The Lancet family journal eBioMedicine found that gut microbiome profiles were strongly associated with markers of metabolic health across both children and older adults, reinforcing the idea that the microbiome reflects—and may help shape—our metabolic resilience over time.
Another large-scale study published in Nature Communications linked specific microbial pathways to body composition, glucose regulation, and liver health, highlighting that what the microbiome does may be just as important as which organisms are present.
In other words, the microbiome is not simply a passenger.
It is an active participant in your physiology.
This month inside Circle Up, our focus is Gut Health & Microbiome.
At its core, this month is about relationship.
How you nourish yourself.
How you receive.
How you respond to stress.
How you learn to trust your body’s signals again.
Because the gut is not just where food is processed.
It is where information is interpreted.
Science with Soul
The gut and brain communicate continuously through the vagus nerve, immune signaling, hormones, and microbial metabolites.
Researchers are increasingly recognizing that a resilient microbiome is associated with metabolic flexibility, lower inflammation, and more robust immune function.
The goal is not to engineer a “perfect” microbiome.
The goal is to create the conditions that allow balance to emerge.
Fiber-rich plants.
Polyphenol-rich foods.
Sleep.
Movement.
Stress regulation.
Meaningful connection.
The body responds to what you do consistently.
This Week’s Ritual
Add one thing this week rather than taking something away.
A serving of berries.
A handful of walnuts.
Beans or lentils.
Fermented vegetables.
A walk after dinner.
Ten minutes outside in the morning light.
Small inputs, repeated consistently, can create meaningful change over time.
Reflection
What is your body trying to tell you right now?
And what might shift if you responded with curiosity instead of control?
Practitioner Picks
A few of the tools we use clinically to better understand and support gut health:
Comprehensive Microbiome Testing
Provides insight into microbial diversity, digestive function, inflammation, and intestinal barrier health.
Food Sensitivity Testing
Can help identify patterns that may be contributing to symptoms such as bloating, fatigue, headaches, or skin flares.
Targeted Gut Support
A personalized protocol may include probiotics, digestive enzymes, glutamine, magnesium, or polyphenol-rich support tailored to your needs.
Because healing the gut is often less about restriction…
And more about creating the conditions for resilience.
Join Circle Up
If you’re looking for a more grounded and informed approach to longevity, Circle Up is our monthly membership designed to help you integrate the science of healthy aging into everyday life.
Each month includes:
• A live teaching session with Dr. Kathryn Dundas, MD, CCFP
• Monthly reflection themes aligned with the Sublime Life Longevity Calendar
• Practical rituals and habit-building tools
• Daily Today’s Pulse emails
• Access to a growing library of science-with-soul resources
For $99/month, Circle Up offers a supportive community and a structured path to help you slow age with intention.
To learn more, visit Sublime Life.
Make Presence Your Protocol ✦ Sublime Life