Probiotics vs. Prebiotics: What Actually Helps Anxiety and Mood?

This is one of my favorite topics to write about.  There is so much misinformation out there and I hope to clear up some of the muck so that you can make an informed decision on what is right for you.  Probiotics and prebiotics can be confusing topics.  All of the marketing and advertising (and people making money off of them) do not help the matter.  Walk into any store and you’ll see shelves full of probiotics promising better digestion, stronger immunity and even improved mood.

But here are questions most people are asking quietly:

👉 What are probiotics and prebiotics?

👉 Do they actually help anxiety and mood… or is something else more important?

The answer may surprise you.

First, let’s simplify the confusion

Probiotics

Probiotics are live microorganisms — bacteria or yeasts — found in:

• Supplements

• Fermented foods (like sauerkraut, kimchi, yogurt alternatives, miso)

They can be helpful in certain situations, especially after illness or antibiotic use.

Prebiotics

Prebiotics are food for your gut bacteria.

They’re fibers and plant compounds found in foods like:

• Beans and lentils

• Oats

• Garlic and onions

• Asparagus

• Bananas

• Leafy greens

They don’t add bacteria — they feed the bacteria you already have.

The gut–brain connection (why this matters for mood)

As you may have learned from my previous blogs, your gut and brain are in constant communication through the gut–brain axis, involving:

• The vagus nerve

• Immune signaling

• Hormones

• Microbial metabolites

Gut bacteria help influence inflammation, neurotransmitter activity, and stress signaling — all of which affect mood and anxiety (Mayer et al., 2015).

This is why gut health is now considered a key piece of mental health science.

The serotonin connection (quick refresher)

About 90% of serotonin — a neurotransmitter involved in mood and emotional regulation — is produced in the gut (Gershon, 2013).

Gut bacteria influence serotonin signaling indirectly by:

• Supporting gut lining health

• Producing short-chain fatty acids (SCFAs) (which help the brain produce its own serotonin)

• Modulating immune and stress responses

So, the question becomes:

👉 What supports gut bacteria best — adding probiotics, or feeding them?

What the science actually shows

Probiotics: mixed results

Research on probiotics and mental health shows inconsistent outcomes.

Some studies suggest certain strains may modestly improve anxiety or depressive symptoms — while others show little effect.

Results vary widely depending on:

• Strain used

• Dose

• Duration

• Individual gut environment

In other words: probiotics are not one-size-fits-all (Asad et al., 2025).

They can be helpful — but they’re not the foundation.

Prebiotics: more consistent support

Prebiotics feed beneficial gut bacteria, allowing them to:

• Multiply naturally

• Produce calming metabolites like SCFAs

• Support gut barrier integrity

• Reduce inflammatory signaling

Higher intake of prebiotic-rich foods is associated with:

• Improved gut microbial diversity

• Reduced inflammation

• Better stress resilience

These effects are more consistent across populations (Guo et al., 2022).

The key insight most people miss

🧠 You can take probiotics — but if you don’t feed them, they don’t stay.

Without prebiotics:

• Probiotic bacteria struggle to survive

• Benefits are often temporary

• Results feel inconsistent

This is why people say:

“Probiotics worked for a while… then stopped.”

The missing piece is food.

So, what actually helps anxiety and mood most?

Not supplements alone.

But a gut-supportive pattern that includes:

• Daily prebiotic-rich plant foods

• Adequate fiber

• Consistent meals

• Reduced ultra-processed foods

• Optional fermented foods (as tolerated)

This approach supports gut–brain communication every day, not just when you remember to take a pill (Jacka et al., 2017).

What you can do today (simple and practical)

1. Feed before you supplement

Before buying a probiotic, ask:

“Am I eating foods that feed my gut bacteria daily?”

Start there.

2. Add prebiotics gently (especially if you do not eat these foods daily)

Choose 1–2 foods per day:

• Oats

• Beans or lentils

• Onions or garlic

• Bananas

• Greens

Increase slowly and drink water.

3. Use probiotics strategically

Probiotics may help:

• After antibiotics

• During travel

• With specific digestive issues

They’re tools — not magic.

4. Remember: consistency beats intensity

Gut health responds best to steady, repeatable nourishment.

Not extremes.

The big takeaway

Probiotics (as supplements) can help sometimes.

Prebiotics (as food) help consistently.

If anxiety or low mood is part of your picture, feeding your gut daily with real food is one of the most reliable ways to support calm and emotional balance.

Want a simple way to try this — without guessing?

That’s exactly why I created the FREE 7-Day Serotonin Reset Plan.

It’s designed to:

• Support the gut–brain axis

• Feed beneficial bacteria naturally

• Stabilize mood and energy

• Reduce anxiety and mental stress

No restriction.No extremes.Just whole-food, plant-based meals that support serotonin and calm.

👉 Download the FREE 7-Day Serotonin Reset here: CLICK HERE!

One more thing:

👉 Want to take a deeper dive into probiotics and prebiotics? Then you'll want to check out my mini course entitled: Feeding Your Inner Garden: Probiotics, Prebiotics & Gut Health

It’s a step-by-step on how to naturally feed your microbiome, the role of probiotics and prebiotics, how to get them from real foods, and the pros and cons of supplements versus natural sources.

You’ll also get downloadable guides to help you choose the right probiotics and prebiotics for your unique needs—making it easy to take actionable steps toward lasting gut health. Plus, you’ll have six months of unlimited access to the course content so that you can learn at your own pace.  Don’t miss your chance to nourish your gut, support your health, and finally feel your best—your inner garden is waiting!

👉 Here's the link for the course: CLICK HERE!

Scientific References

Asad, A., et al. (2025). Effects of prebiotics and probiotics on symptoms of depression and anxiety. Nutrition Reviews, 83(7).

Gershon, M. D. (2013). Serotonin is a sword and a shield of the bowel. Transactions of the American Clinical and Climatological Association, 124, 100–115.

Guo, C., et al. (2022). Gut–brain axis: Focus on short-chain fatty acids. Frontiers in Neuroscience, 16, 847509.

Jacka, F. N., et al. (2017). Dietary improvement for adults with depression (SMILES trial). BMC Medicine, 15, 23.

Mayer, E. A., Tillisch, K., & Gupta, A. (2015). Gut/brain axis and the microbiota. Journal of Clinical Investigation, 125(3), 926–938.