Can 'Good' Gut Bacteria Actually Help You Feel Better?

As rates of stress, anxiety, and depression continue to rise, scientists are searching for new ways to support mental health, especially for people who don’t respond fully to existing treatments. 

One promising area of research involves the gut microbiome.

The term 'gut microbiome' refers to the vast community of bacteria and other microorganisms living in the digestive tract, and mounting evidence suggests these microbes may influence not just digestion, but also brain function and mood⁽¹⁾.

The Gut–Brain Connection

Your gut is home to trillions of bacteria, some beneficial, others less so. When this microbial ecosystem is balanced and diverse, it may play a role in regulating mood. This relationship is known as the gut–brain axis, and it's a two-way communication system linking the gastrointestinal tract and the brain through nerves (especially the vagus nerve), immune responses, and hormones.

What Animal Studies Reveal

In animal models, particularly mice, researchers have shown that altering gut bacteria can change behavior. In one striking example, mice given gut microbes from humans with depression began to show signs of depressive behavior themselves⁽²⁾. 

These findings suggest that gut bacteria may influence emotional processing and behavior. Some gut bacteria appear to reduce inflammation, an immune response that when chronic, is linked to depression and fatigue⁽³⁾. Others may lower levels of stress hormones such as cortisol⁽⁴⁾. 

This complex signaling hints at why gut health could influence mental health.

Can Probiotics Support Mental Well-Being?

These insights have led researchers to ask whether probiotics could positively affect mood in humans. Some clinical studies suggest they might reduce symptoms of anxiety, depression, or stress⁽⁵⁾. 

However, results have been mixed.

One limitation is the way most studies measure emotional changes, typically through questionnaires completed before and after the intervention. While useful, these surveys may miss subtle or short-term shifts in mood, especially in healthy individuals.

A New Approach: Daily Mood Check-Ins

To address this, a recent study tested probiotics in healthy young adults using a more nuanced approach. Participants received either a probiotic supplement or a placebo for four weeks. In addition to standard psychological questionnaires, they were asked to rate their mood every day on a scale from 0 to 100⁽⁶⁾.

The simple daily question, “How are you feeling today?”, provided a real-time glimpse into emotional patterns over time.

What The Study Found

The daily mood ratings revealed that participants taking probiotics reported a gradual reduction in negative emotions such as sadness, anger, or stress. They didn’t necessarily feel happier overall, but they felt less bad. Interestingly, this improvement didn’t show up on the standard questionnaires.

The shift became noticeable after about two weeks, which aligns with how long antidepressant medications typically take to begin working. Additionally, participants who were more anxious or risk-averse at the beginning of the study seemed to benefit the most from the probiotics.

Why It Matters

This study suggests two key takeaways:

1. Probiotics may help reduce negative mood in some healthy individuals. 
2. How we measure emotional change matters. Simple, consistent check-ins may offer a clearer picture than occasional, complex surveys.

What It Means for You

• Probiotics might help ease negative emotions, particularly in people who are prone to worry or stress.
• Tracking your mood daily, even with just a quick self-rating can be a valuable tool for emotional awareness.
• The gut and brain are deeply interconnected. Taking care of your digestive health might support mental well-being, too.

Looking Ahead

More research is needed to understand exactly how probiotics influence the brain and which individuals benefit most. But early findings indicate that nurturing your gut could become one part of a holistic approach to emotional health.

And perhaps the most powerful insight is also the simplest: meaningful mental health support may start with just one question, which is “How are you feeling today?”

If you're looking to support your gut health, a daily probiotic is a great place to start.

Pro+Flora is multi-strain probiotic that helps you stay on point by providing your gut flora the fuel they need to keep you healthy and strong. By balancing intestinal microflora, probiotics play an important role in regulating intestinal function and digestion and more. 

Take control of your gut health and empower your body to function at its best with PRO+FLORA probiotic!

References:
    1.    Bruce-Keller AJ, Salbaum JM, Berthoud HR: Harnessing Gut Microbes for Mental Health: Getting From Here to There. Biol Psychiatry 83:214-223, 2018
    2.    Kelly JR, Borre Y, C OB, et al: Transferring the blues: Depression-associated gut microbiota induces neurobehavioural changes in the rat. J Psychiatr Res 82:109-18, 2016
    3.    Dantzer R, O'Connor JC, Freund GG, et al: From inflammation to sickness and depression: when the immune system subjugates the brain. Nat Rev Neurosci 9:46-56, 2008
    4.    Messaoudi M, Violle N, Bisson JF, et al: Beneficial psychological effects of a probiotic formulation (Lactobacillus helveticus R0052 and Bifidobacterium longum R0175) in healthy human volunteers. Gut Microbes 2:256-61, 2011
    5.    Allen AP, Hutch W, Borre YE, et al: Bifidobacterium longum 1714 as a translational psychobiotic: modulation of stress, electrophysiology and neurocognition in healthy volunteers. Transl Psychiatry 6:e939, 2016
    6.    Johnson KVA, Steenbergen L: Probiotics reduce negative mood over time: the value of daily self-reports in detecting effects. npj Mental Health Research 4:10, 2025