psychobiotic supplements, science and caution

Christopher Lowry, a professor of integrative physiology at the University of Colorado Boulder, states there is an “absolute, unequivocal link” between gut health and mental vitality. This bidirectional relationship, known as the gut-brain axis, means a healthy gut can improve brain function, while stress can conversely damage gut health.

Lowry has spent 25 years researching how bacteria communicate with the brain. He notes that when individuals increase gut resilience, they may boost mental and emotional fitness, which then further strengthens the gut.

How does the gut-brain axis influence mental health?

Research into the soil bacterium Mycobacterium vaccae suggests a direct link between microbes and mood. First discovered in the 1970s in mud near Lake Kyoga in Uganda, the bacterium was found by immunologists to play a role in the effectiveness of leprosy vaccines in the region.

According to Lowry, this bacterium selectively activates serotonin neurons in the brain associated with antidepressant effects. It also suppresses inflammation linked to stress-related disorders and anxiety.

Lowry connects this to a concept called “Old Friends,” a term used by a University College London colleague. This describes a 200-million-year relationship between mammals and beneficial microorganisms that bolstered health before modern hygiene and indoor living reduced human exposure to these microbes.

Did You Know? Mycobacterium vaccae was first identified in the 1970s in Ugandan mud near Lake Kyoga while researchers were studying why leprosy vaccines worked better in that specific population.

What evidence supports the use of psychobiotics in psychiatry?

Lowry and colleague Lisa Brenner at the VA have applied these findings to military veterans suffering from traumatic brain injury and PTSD. They recently completed a large NIH-funded clinical trial, which Lowry describes as the first of its kind to examine probiotics within psychiatry.

Lowry expects to publish several papers based on this research later this year. He argues that the potential impact is vast when scaling the effects of a single strain to the trillions of microbes within the human gut microbiome.

Expert Insight: Samantha Carter notes that the transition from animal research to human application remains the highest hurdle for the industry. The failure of promising strains in human trials underscores the necessity of the rigorous, placebo-controlled clinical trials Lowry advocates for to move beyond “woo-woo” claims.

How is the supplement industry responding to gut-brain research?

The natural products industry is expanding its “psychobiotic” offerings. Innova Market Insights reports that gut-brain health claims on supplement packaging increased by 11% between 2020 and 2025.

Plants, the microbiome, and mental health | Christopher A. Lowry | TEDxMileHigh

Data from NBJ indicates that gut health currently holds a 6.2% market share of the supplement industry and is growing at a rate of 6.5%. Several companies showcased products at this year’s Natural Products Expo West:

Morinaga Nutritional Foods: Displayed a postbiotic strain supported by clinical studies for mood.
Novonesis: Introduced MindAble 1714, a probiotic designed to reduce cortisol after acute stress.
Pendulum Therapeutics: Launched a brand focused on gut bacteria nationwide at Sprouts Farmers Market in April.

What are the risks of gut-brain health supplements?

Lowry warns that animal success does not always translate to humans. He cites Lactobacillus rhamnosus JB-1, a strain that showed promise in animal research but failed during human trials.

Lowry is currently co-founding Kioga, a biotech startup aimed at replacing the beneficial bacteria humans lost through modernization. The company is in a seed funding round, and products are not yet available for sale.

Until science-backed supplements are widely available, Lowry recommends eating fermented foods, consuming a high volume of plants, spending time outdoors, and exposing oneself to soil.

Frequently Asked Questions

What is the difference between prebiotics and probiotics?
Probiotics are living organisms, while prebiotics are effectively fiber that serves as food for those probiotics.

What are postbiotics?
Postbiotics are the substances that probiotics produce or leave behind after consuming prebiotics.

Can stress affect the gut?
Yes, according to Christopher Lowry, the link is bidirectional, and stress is one of the factors that detracts from gut health.

Do you prioritize outdoor activity and soil exposure as part of your mental health routine?