The Gut-Brain Connection: How Gut Health Affects Brain Function

Written by: Tennant Products Editorial Team
Reviewed by: Patsy Scott, CHN (Certified Holistic Nutritionist)
Last Updated: February 2026

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TL;DR

• The gut-brain connection refers to the communication between the digestive system and the brain through the gut-brain axis.
  

• The gut microbiome influences mood, immune activity, inflammation, and energy levels.
  

• Stress, medications, and environmental toxins can disrupt digestive balance.
  

• Diet, lifestyle habits, and targeted supplements for digestive health may support microbiome balance.
  

• A structured approach that includes prebiotics, probiotics, polyphenols, and liver support can help maintain digestive and cognitive health.
  

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What Is the Gut-Brain Connection?

The gut-brain connection describes the two-way communication between the gastrointestinal tract and the central nervous system. This communication network is called the gut-brain axis.

The gut microbiome, which includes bacteria, viruses, and fungi living in the digestive tract, plays a central role in this relationship. These microbes produce metabolites and signaling molecules that interact with immune pathways, hormone systems, and nerve signaling.

Communication occurs through:

• The vagus nerve
  

• The bloodstream
  

• The lymphatic system
  

• The enteric nervous system
  

The enteric nervous system is sometimes referred to as the “second brain” because it contains millions of nerve cells that directly influence digestion and communicate with the brain.

Research shows that changes in the gut microbiome may influence inflammation, stress responses, and mood regulation. This does not mean the microbiome causes every condition, but it can contribute to systemic balance.

Why the Gut Microbiome Matters for Brain and Immune Health

A large portion of immune activity is associated with the gastrointestinal tract. When the gut lining is irritated or microbial balance is disrupted, low-grade inflammation may occur.

Imbalances in the microbiome, often called dysbiosis, have been studied in relation to:

• Irritable Bowel Syndrome
  

• Mood changes
  

• Fatigue
  

• Brain fog
  

• Food sensitivities
  

For example, IBS was once considered primarily psychological. Current research recognizes that microbial imbalance and inflammation can influence both digestive and neurological symptoms.

The gut-brain connection highlights that digestive health and mental health are interconnected.

What Impacts the Gut Microbiome?

Several lifestyle factors can affect the microbiome and digestive balance.

1. Medications

Certain medications may alter gut bacteria composition, including:

• Antibiotics
  

• NSAIDs
  

• Acid-blocking drugs
  

• Steroids
  

Antibiotics are essential when medically necessary. However, they may temporarily reduce beneficial bacteria. Recovery of microbial diversity can take time and may benefit from dietary and digestive health supplements.

2. Environmental Toxins

Exposure to heavy metals, pesticides, and industrial chemicals may influence gut integrity and mitochondrial function. Some research suggests that environmental stressors can alter microbial diversity.

Reducing exposure and supporting natural detox pathways may help maintain digestive balance.

3. Chronic Stress

Stress activates cortisol. Elevated cortisol levels may affect gut motility, intestinal permeability, and microbial composition.

Chronic stress has also been associated with mineral depletion, including magnesium, which plays a role in nervous system regulation.

Managing stress is a key component of digestive health and overall well-being.

How to Support the Gut-Brain Connection

Supporting digestive health involves nutrition, lifestyle changes, and in some cases, supplements for good digestive health.

1. Eat Fiber-Rich, Colorful Foods

Plant-based foods provide:

• Prebiotic fibers
  

• Polyphenols
  

• Micronutrients
  

These compounds help nourish beneficial gut bacteria. A diverse diet supports microbial diversity.

2. Limit Highly Processed Foods

Reducing refined sugar, artificial sweeteners, and heavily processed foods may support microbial balance.

Some individuals also benefit from temporarily limiting gluten or dairy if sensitivities are suspected.

3. Support Liver Function

The liver plays a central role in detoxification. Nutrients such as:

• Phospholipids
  

• Choline
  

• Methionine
  

• Antioxidants
  

may support natural detox processes. Whole foods rich in healthy fats can assist liver function.

Certain natural supplements for digestive health are formulated to include detox-support nutrients such as glutathione precursors or humic and fulvic compounds.

Dr. Tennant’s® Liver Detox Tea is formulated to support healthy liver function as part of a broader digestive and detox strategy. The suggested use is six drops in warm water, often combined with honey and coconut oil. This preparation is intended to support the body’s natural detox processes and can be incorporated into an evening routine.

As with all supplements for digestive health, individuals should consult a healthcare professional, especially if they have liver conditions, take medications, or are pregnant.

4. Consider Targeted Digestive Health Supplements

For individuals seeking additional support, digestive health supplements may help support microbial balance, gut lining integrity, and natural detox pathways.

Common categories of supplements for digestive health include:

• Probiotics
  

• Prebiotics
  

• Polyphenol blends
  

• Gut lining support nutrients
  

• Detox-support compounds
  
  

Some of the best supplements for digestive health combine multiple mechanisms, including fiber, beneficial bacteria, antioxidant support, and nutrients that assist cellular function.

Microbiome and Gut Lining Support

Dr. Tennant’s® Microbiome Support is formulated to provide:

• Fiber to nourish beneficial bacteria
  

• Phospholipids for cellular membrane support
  

• Glutamine to support intestinal lining integrity
  

• N-acetyl-cysteine to support antioxidant pathways
  

• Glutathione to support cellular antioxidant balance
  

This fits within natural supplements for digestive health that aim to support both microbial diversity and intestinal barrier health.

Probiotic and Mycobiome Support

Dr. Tennant’s® GI 60 Probiotics includes targeted probiotic strains with prebiotics in a delayed-release delivery system designed to protect beneficial bacteria from stomach acid.

Dr. Tennant’s® Fungal Detox is formulated to support balance within the mycobiome, the fungal portion of the microbiota. Although fungi represent a smaller portion of the gut ecosystem, maintaining balance may support digestive and immune function.

Detox and Nutrient Transport Support

Dr. Tennant’s® Raw Materials™ contains humic and fulvic compounds. These compounds are used in some natural digestive health supplements to support nutrient transport and antioxidant activity.

Humic and fulvic substances have been studied for their ability to bind certain compounds within the digestive tract and assist with mineral transport. In the context of supplements for good digestive health, they are positioned as supportive of the body’s existing detox pathways rather than as standalone detox solutions.

A Structured Gut Reset Approach

Dr. Tennant’s® Gut Bootcamp Bundle combines:

• Dr. Tennant’s® Microbiome Support
  

• Dr. Tennant’s® GI 60 Probiotics
  

• Dr. Tennant’s® Fungal Detox
  

This system is designed to support bacterial balance, fungal balance, and gut lining integrity in a structured format.

As with all digestive health supplements, these products are not intended to diagnose, treat, cure, or prevent disease. Individuals with medical conditions or those taking medications should consult a licensed healthcare professional before beginning supplements for digestive health.

The Role of the Mycobiome

The gut microbiota includes both bacteria and fungi. The fungal community, called the mycobiome, represents a smaller percentage of the microbiome but may still influence immune activity and digestive balance.

Supporting both bacterial and fungal balance may be beneficial when considering natural digestive health supplements.

Putting It All Together

The gut-brain connection emphasizes that digestive health influences immune signaling, inflammation, and neurological function.

A balanced approach includes:

• Whole foods
  

• Stress management
  

• Environmental awarenes
  

• Evidence-informed supplements for digestive health
  

Small, consistent habits often produce more sustainable results than extreme interventions.

FAQs

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DISCLAIMER: This content is intended for informational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always consult your physician or qualified healthcare provider before starting any new supplement, especially if you are pregnant, nursing, taking medications, immunocompromised, or have an existing health condition. Individual needs and responses may vary. Use this information as a guide and modify based on your healthcare provider’s recommendations.

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