What Is the Microbiota–Gut–Brain Axis?

Your gut hosts trillions of microorganisms—bacteria, fungi, and more—that communicate with your brain via:

• The vagus nerve
• Immune and inflammatory signaling
• Short-chain fatty acids (SCFAs)
• Microbiota-influenced neurotransmitters

Major reviews now describe the microbiome as a key regulator of brain function, mood, and cognition.^{(1), (2), (4)}

Human studies have also linked gut microbial diversity and composition with cognitive performance and cognitive aging.⁽³⁾

How Gut Health Influences Cognitive Function

1. Inflammation and barrier integrity

The gut lining is only one cell thick. When it becomes overly permeable (“leaky gut”), inflammatory molecules and bacterial products can enter the bloodstream, influencing the brain and mood. Systemic inflammation is strongly associated with mood disorders and cognitive decline.^{(1), (3), (4)}

2. Microbial production of brain-active compounds

Healthy gut microbes produce metabolites and compounds that support brain function, including:

• SCFAs with anti-inflammatory and neuroactive effects
• Precursors for serotonin and other neurotransmitters
• Compounds that interact with GABA and other signaling systems

Disturbances in this microbial “conversation” can contribute to brain fog and mood symptoms.^{(1), (2)}

3. Immune and stress signaling

The gut is a major immune organ. Microbiome disruptions can increase inflammatory cytokines and alter the stress response, both of which have been linked to changes in cognition and emotional regulation.^{(1), (2), (4)}

First Steps: Habits That Support Gut–Brain Health

• High-fiber diet – feeds beneficial microbes and supports SCFA production.^{(1), (4)}
• Fermented foods – may help support microbial diversity and resilience.⁽¹⁾
• Stress management – chronic stress can disrupt the microbiota and gut barrier.^{(2), (4)}
• Sleep + physical activity – important for healthy immune and inflammatory balance.⁽⁴⁾

How Gut Lining Support Helps the Gut–Brain Axis

A healthy gut lining acts as a selective barrier, allowing nutrients in while keeping irritants and toxins out. Supporting this barrier may help calm inflammation and, indirectly, support brain health.^{(1), (3)}

Gut Assist™ combines L-glutamine, arabinogalactan, deglycyrrhizinated licorice (DGL), and aloe leaf extract—each studied for gut and mucosal support.

L-Glutamine

L-glutamine is a key fuel for intestinal epithelial cells and supports tight junctions and barrier integrity. A recent meta-analysis of clinical trials in adults found that glutamine supplementation above certain doses was associated with reductions in markers of intestinal permeability.^{(5), (6)}

Arabinogalactan

Arabinogalactan is a soluble dietary fiber that acts as a prebiotic, selectively feeding beneficial gut bacteria. Newer work using 16S rRNA sequencing and single-cell profiling supports its role as a prebiotic that beneficially shapes microbiota composition and activity.⁽⁷⁾

Deglycyrrhizinated Licorice (DGL)

DGL is licorice that has had glycyrrhizin largely removed to reduce the risk of blood pressure–related side effects. Classic controlled trials of DGL and related licorice preparations in patients with gastric or duodenal ulcers show symptomatic improvement and mucosal support, even when effects on ulcer healing are modest or variable.⁽⁸⁾

Aloe Leaf Extract

Oral aloe vera gel has been studied in inflammatory bowel conditions; in one randomized, double-blind, placebo-controlled trial in active ulcerative colitis, aloe vera gel showed higher clinical response rates than placebo and reductions in histologic disease activity.⁽⁹⁾

⭐ Dr. Danielle Recommends
Gut Assist™ — Nourish and Protect Your Gut Lining

Gut Assist™ is formulated to strengthen the intestinal lining, support healthy inflammation levels, and promote smoother digestion—key components of gut–brain support.†

Key Benefits:

• Reinforces the gut barrier†
• Supports mucosal protection†
• Nourishes beneficial gut bacteria†
• Promotes digestive comfort†

Key Ingredients: L-Glutamine, Arabinogalactan, DGL Licorice, Aloe Leaf Extract.

How to Use: Mix one scoop daily into water or a smoothie. Consistency and daily use produce the best results.

👉 Learn more or purchase at DrDanielle.com.

Spore-Based Probiotics and the Brain–Gut Connection

Spore-forming probiotics such as certain Bacillus subtilis strains are naturally hardy and designed to survive the acidic environment of the stomach and reach the intestines alive.

Randomized, double-blind, placebo-controlled trials in adults have found that Bacillus subtilis strains can reduce gas-related symptoms (like bloating and flatulence), improve overall GI symptom scores, and support everyday digestive comfort.^{(10), (11)}

Probiotics and Cognitive Function

Several clinical trials and meta-analyses suggest that probiotics may improve cognitive performance in people with Alzheimer’s disease and mild cognitive impairment (MCI), likely via inflammation, oxidative stress, and metabolic pathways related to the gut–brain axis.^{(12), (13), (14)}

⭐ Dr. Danielle Recommends
Spore-Based Probiotic — Resilient Gut–Brain Support

This spore-based probiotic pairs perfectly with Gut Assist™ to help restore microbial balance while the gut lining is being nourished and supported†.

Why Spore-Based?

• Survives stomach acid†
• Colonizes effectively†
• Reduces bloating & indigestion†
• Supports immune balance†
• Complements gut–brain axis health†

How to Use: Take two capsules daily, with a meal.

👉 Learn more or purchase at DrDanielle.com.