People often associate bacteria with harmful germs that make us sick, but our bodies contain trillions of microbial organisms responsible for maintaining our well-being.

Bacteria that naturally exist in our digestive tracts influence our gastrointestinal and immune function. Likewise, probiotics have become a popular way to add more “good bacteria” to the gut microbiome to support gut health.

Interestingly, some probiotics can also impact the brain – another reason why the phrase "you are what you eat" applies.

Lactobacillus plantarum PS128, or “PS128,” is one such psychobiotic. Clinical studies suggest it can provide dietary management for autism. 

What are psychobiotics?

Psychobiotics have recently emerged as a subject of great interest among mental health enthusiasts and researchers alike. A psychobiotic is defined as “a live organism that, when ingested in adequate amounts, produces a mental health benefit.” While the mechanisms by which such bacteria exert their psychobiotic potential are not completely understood, they may act via one or more of the following: 

• Hypothalamic-pituitary-adrenal (HPA) axis
• Modulation of neurotransmitter activity in the brain and/or gut
• Modulation of immune response

This burgeoning area of research has led to discoveries about the so-called gut-brain axis - the ways in which gut and brain influence one another via the vagus nerve, neurotransmitters and other means. For instance, some psychobiotics appear to modulate the nervous system of animals by balancing levels of the neurotransmitters dopamine and serotonin in the brain. 

Studies also suggest that certain psychobiotic strains could support gut microbiome to brain signaling in people. The science of psychobiotics not only demonstrates unexpected benefits of probiotics, but also opens up exciting possibilities for enhancing mental and neurological health through certain medical foods.

Is PS128 safe?

PS128 is safe for most people. It has been reported to have a good safety profile and low toxicity. Genetic sequencing shows that it lacks enzymes required to produce bioamines, such as histamine, and the genes related to antibiotic resistance. PS128 possesses the characteristics for Qualified Presumption of Safety (QPS) and has been self-affirmed as GRAS (generally recognized as safe).

Nevertheless, it is recommended to consult with a healthcare professional before taking PS128. Why? Your individual circumstances, including immune system function and other products you take, may be relevant to a health care provider's choice to recommend a specific type of probiotic to you.

Is Lactobacillus plantarum the same as PS128?  

Lactobacillus plantarum and Lactobacillus plantarum PS128 are not quite the same thing. As with any living thing, scientists classify probiotic organisms based on genus and species, and within those species are strains; this video provides a helpful visual aid to understand how probiotics are categorized, as well as the importance of strain specificity.

In this case, Lactobacillus is a genus, and plantarum is a species within that genus. L. plantarum has many strains, just like dogs have many breeds, each with unique genetic traits that give them distinct characteristics and effects. For instance, research shows that different strains of Lactobacillus plantarum have varying abilities to produce organic acids and inhibit the growth of microbial pathogens.

Lactobacillus plantarum PS128 is a specific strain that has demonstrated a particularly strong ability to modulate neurotransmitter levels and affect mental health in preclinical studies. It has also been shown to provide dietary management of autism in human clinical studies. Other strains of L. plantarum will not necessarily have these same psychobiotic characteristics.

Because of this vast variety within genera, species, and strains, knowing the strain of probiotic you're taking (and the CFUs provided by the product) is essential. It affects not only the benefits you can expect, but perhaps also your tolerance and potential side effects. Thus, when it comes to probiotics, it's not just about taking any product with “L. plantarum” on the label, but choosing the specific strain that meets your needs.

Does PS128 work for people with autism?   

Four clinical studies have found that PS128 may be able to help some Autistic individuals. Study participants were scored for behaviors that the medical establishment associates with autism. These include certain neurodiverse behaviors, coping mechanisms for mental health challenges, and others. The results of these four studies taken together suggest that a 60 billion CFU serving of PS128 per day has the ability to support dietary management of autism. 

A real-world study was conducted involving 131 Autistic children and adolescents, assessing the impact of PS128 as compared to other probiotics taken alongside their existing treatments with local physicians. Those taking PS128 showed greater improvements than the group taking other probiotics, all while experiencing fewer side effects.

One of the three randomized, controlled trials of PS128 in autism examined how PS128 psychobiotic might impact Autistic boys aged 7-15. Results showed that those who took PS128 resorted to less “opposition and defiance” behaviors, with younger children exhibiting significant behavioral changes compared to the placebo group. Several other behavioral signs decreased after four weeks of taking this particular probiotic supplement, though further research will be needed to better understand its effects on a broader scale.

How to shop for PS128

Clinically relevant amounts of PS128 (60 billion CFUs) are not available from any known food. Therefore, for dietary management of autism using this probiotic, PS128 should be obtained through a probiotic medical food.

Bened Life is the only authorized online retailer of PS128 and Neuralli MP in the US and Canada. Bened Life-authorized health care provider partners may also provide it in their clinics.  

PS128 is not shelf stable and should be refrigerated to keep its effectiveness through its “best by” date. Therefore, it’s best to purchase it from a retailer who stores it cold and ships fast. It's also important to check the expiration date to ensure that the product is fresh and effective. By keeping these factors in mind, you can shop for PS128 with confidence and ensure that you're getting a high-quality product.

Is PS128 for you? 

Lactobacillus plantarum PS128 is a specific strain of L. plantarum that has psychobiotic properties in animals and humans with certain mental health and neurological conditions. It supports the dietary management of autism. 

While PS128 is self-affirmed to be GRAS (generally recognized as safe), individual responses may vary. It is essential to consult with a health care professional before taking any probiotic medical food, and it is recommended before taking any dietary supplement.

Recommended reading:

How to Get the Most Out of Neuralli MP

PS128 Probiotic & Parkinson’s - How Does it Work? (on Parkinson's News Today)

What Are Psychobiotics?