Although Lactobacillus species are not part of the “core” bacteriome of the human breast milk microbiome, they carry notable promise as probiotics.

Lactiplantibacillus plantarum (L. plantarum), for instance, formerly known as Lactobacillus plantarum1, is a Gram-positive lactic acid bacterium2 commonly found in fermented foods and in our own gastrointestinal tract. 

• Lactobacillus plantarum was renamed to Lactiplantibacillus plantarum in 2020 because advanced genetic sequencing revealed that the Lactobacillus genus was too diverse to be classified under a single group. 
• The genus was officially split into 25 new, smaller genera to reflect more accurate evolutionary, genetic, and metabolic relationships. 

• Lactic acid bacteria are a group of Gram-positive microorganisms characterized by their thick peptidoglycan cell wall, which retains the crystal violet dye used in Gram staining. 
• They are non-spore-forming and acid-tolerant, and can appear as either rod-shaped or cocci. 
• Their defining feature is that they produce lactic acid as the main end product of carbohydrate fermentation.

Research has linked L. plantarum to antioxidant, anticancer, anti-inflammatory, antiproliferative, anti-obesity, and anti-diabetic effects.

Even more inspiring, emerging studies suggest that it may help enhance cognitive function in individuals with major depression and may ease stress and anxiety in adults. 

The Lactiplantibacillus plantarum Probio87 strain (Probio87)

The Lactiplantibacillus plantarum Probio87 strain (Probio87) was discovered in the nurturing environment of human breast milk.

Motivated by its natural origin, the research team set out to explore Probio87 in vitro probiotic potential in depth. 

They examined its physiological resilience, ensured its safety, and studied its antimicrobial and anticancer properties, with a special focus on supporting vaginal and cervical health.

Result

Probio87 demonstrated several promising functional and safety characteristics:

A. Probio87 showed strong tolerance to acidic conditions and bile, efficient adhesion to mucin, and broad carbohydrate utilization. It preferentially utilized short-chain prebiotics such as fructooligosaccharides (FOS) and galactooligosaccharides (GOS) over inulin.

Probio87 is able to survive the highly acidic conditions of the stomach (pH 1.5–3.5) and withstand the bile salts present in the small intestine. 

It adheres strongly to mucin, the main protein in the mucus layer that coats the gut wall. This strong adhesion allows the strain to anchor itself to the gut lining, forming a physical barrier that helps crowd out and block harmful pathogens from attaching and causing infection.

In addition, Probio87 produces a wide range of enzymes that can break down different sugars and complex fibers. This enables the strain to access many energy sources and effectively compete with harmful bacteria for nutrients in the diverse environment of the human gut.

Probio87 also works particularly well with the short-chain prebiotics FOS and GOS, forming a potent synbiotic combination. 

Because FOS and GOS have smaller molecular structures than inulin (a long-chain prebiotic), Probio87 can ferment them quickly and efficiently, supporting rapid bacterial growth and colonization in the gut.

B. Probio87 complied with the European Food Safety Authority (EFSA) antibiotic safety criteria, indicating an acceptable safety profile with respect to antibiotic resistance.

When a probiotic strain meets the EFSA antibiotic safety criteria, it has been carefully evaluated to ensure it cannot transfer harmful antibiotic-resistance genes to other bacteria in your gut. 

This helps prevent the accidental creation of “superbugs”3 and protects the effectiveness of antibiotics you may need in the future.

• A superbug (or multidrug-resistant microbe) is any kind of infection that is hard to get rid of because it is resistant to (unable to be destroyed with) available treatment. 

• Most superbugs are bacteria that have developed antibiotic resistance, especially to multiple antibiotics. There are also fungal superbugs that are resistant to antifungal medications. 

There are two main requirements for EFSA compliance:

I. No acquired or transferable resistance (genotypic testing)

The strain’s entire DNA is analyzed using Whole Genome Sequencing (WGS). This confirms that it does not carry antibiotic-resistance genes4 on mobile genetic elements5 such as plasmids. 

Without these mobile genes, the probiotic cannot pass resistance traits6 to harmful bacteria like E. coli or Salmonella.

• Antibiotic resistance genes (ARGs) are DNA segments allowing bacteria to survive antibiotic treatment by degrading drugs, modifying targets, or pumping antibiotics out. 
• Located on chromosomes or mobile plasmids, these genes spread rapidly between bacteria—even across species—via horizontal gene transfer. 
• They pose a major global health threat, reducing treatment efficacy for infections.  

• Mobile genetic elements are sequences of genetic material that can change positions on chromosomes and be exchanged between bacteria and species, influencing microbial evolution and the spread of antibiotic resistance. 

• Pass resistance traits refer to the biological mechanism by which bacteria, fungi, or pests transfer their ability to survive exposure to antibiotics, antifungals, or pesticides to their offspring or to other neighboring microbes. 
• These traits—encoded in DNA—allow the organism to withstand treatments designed to kill them, leading to the rapid spread of resistance within a population. 

II. Susceptibility to key antibiotics (phenotypic testing)

The strain is grown in the presence of important antibiotics (i.e., ampicillin, tetracycline, and erythromycin). 

Scientists then determine the Minimum Inhibitory Concentration (MIC), which is the lowest antibiotic dose that stops the strain from growing. 

For EFSA compliance, these MIC values must be below specific microbiological cut-off levels, showing that the bacterium remains naturally sensitive to standard medical antibiotics.

C. Its cell-free supernatant (CFS) displayed potent antimicrobial activity, including complete inhibition of the fungal pathogen Candida albicans.

CFS is the liquid byproduct that remains after probiotic bacteria are grown in a laboratory and then removed using centrifugation. 

Because all live bacteria are spun out, this liquid contains no living microbes; instead, it retains the active therapeutic compounds produced by the bacteria during growth.

CFS is rich in bioactive substances (often referred to as “biotics”) that can effectively kill or inhibit the growth of bacteria, molds, and fungi. 

In other words, Probio87 produces a fluid filled with natural antimicrobial agents that remain active even after the bacteria themselves are gone.

Research shows that these secretions can completely halt the growth of Candida albicans, an opportunistic yeast responsible for common conditions such as thrush, vaginal yeast infections, and oral fungal overgrowth.

D. Probio87 selectively inhibited Lactobacillus iners (L. iners) without affecting Lactobacillus crispatus (L. crispatus), suggesting a favorable modulation of the vaginal microbiota.

Probio87 is formulated to selectively suppress the overgrowth of L. iners, a bacterial species linked to a higher risk of vaginal infections. 

This targeted approach helps remove a key factor that can contribute to infection, while preserving L. crispatus, which is widely recognized as one of the body’s most important naturally protective vaginal bacteria.

By reducing L. iners, Probio87 helps free up space and resources within the vaginal environment. Therefore, this creates more favorable conditions for L. crispatus to grow and become the dominant species in the microbiome.

Shifting the vaginal microbiome from being dominated by L. iners to being dominated by L. crispatus supports a more stable and protective environment, making it less susceptible to infections.

a. Understanding the Target: Lactobacillus iners

L. iners is part of the Lactobacillus family, which is generally considered beneficial for vaginal health. However, L. iners behaves differently from its more protective relatives. 

It is unstable and highly opportunistic, meaning it can thrive in environments where the vaginal microbiome is under stress or beginning to shift toward imbalance.

The Risk Factor: Elevated levels of L. iners have been associated with fluctuating vaginal pH and a reduced ability to defend against infections. 

Studies link its dominance to an increased likelihood of developing Bacterial Vaginosis (BV)7, sexually transmitted infections, and persistent human papillomavirus (HPV)8. 

• Bacterial Vaginosis (BV) is a very common vaginal infection caused by an overgrowth of harmful bacteria, which disrupts the natural balance of "good" bacteria (lactobacilli) in the vagina. It causes symptoms like a thin, grey/white fishy-smelling discharge, although many people have no symptoms. 

• Human Papillomavirus (HPV) is the most common sexually transmitted infection (STI) globally. It is a group of over 200 related viruses, some of which cause harmless warts, while others can lead to precancerous cell changes and certain cancers. 

L. iners is often detected at the point when the vaginal environment is transitioning from a healthy state toward infection.

b. Understanding the Protected Microbe: Lactobacillus crispatus

L. crispatus is widely regarded as the most protective bacterium for vaginal health.

The Protective Shield: L. crispatus produces high levels of L-lactic acid and hydrogen peroxide. These substances help maintain a consistently acidic vaginal pH, which acts as a natural barrier against harmful pathogens, viruses, and yeast. 

By stabilizing the environment, L. crispatus plays a central role in preventing infections and supporting overall vaginal health.

E. In cervical cancer cell models, the CFS significantly reduced cell proliferation and angiogenesis markers (p < 0.05). It also induced apoptosis and cell cycle arrest in HPV-positive cells, while having minimal impact on HPV-negative C-33A cells.

The fluid produced by Probio87 greatly reduces or even stops the rate at which cervical cancer cells divide and multiply. In this way, it helps prevent the tumor mass from growing or spreading.

Tumors rely on a process called angiogenesis to survive and expand. During angiogenesis, tumors create new blood vessels that draw in oxygen and nutrients from the body. 

By interfering with this process, Probio87 effectively starves the tumor by limiting its ability to form a blood supply.

The statistical result of p < 0.05 indicates that the observed reduction is highly significant and very unlikely to be due to chance.

Probio87 also influences key cellular mechanisms. Apoptosis, for instance, is a form of programmed cell death, where cells are instructed to self-destruct in a controlled way. Cell cycle arrest is another mechanism, in which a cell’s internal replication machinery is halted so it can no longer divide. 

Cancer cells are dangerous because they ignore the body’s normal signals to stop dividing and to die when damaged. Probio87 helps overcome this resistance by triggering apoptosis and enforcing cell cycle arrest, thereby forcing these harmful cells to self-destruct.

Cervical cancer is driven in almost all cases by high-risk HPV strains, such as HPV-16 and HPV-18. These viruses insert their oncogenes9 (E6 and E7) into human DNA, pushing cells to grow abnormally.

• Oncogenes are mutated genes that have the potential to cause cancer. Before mutating, they are normal, healthy genes called proto-oncogenes that regulate cell growth, division, and survival. When damaged, they become oncogenes and drive cells to grow uncontrollably. 

The metabolites in Probio87’s CFS are interfering with the specific genetic changes found in HPV-driven cancer cells, like the HeLa10 and CaSki11 cell lines. 

• HeLa Cell Line, in 1951, a 31-year-old African-American woman, went to Baltimore’s Johns Hopkins Hospital to be treated for cervical cancer. 
• Some of her cancer cells began being used in research due to their unique ability to continuously grow and divide in the laboratory. 
• These so-called “immortal” cells were later named “HeLa” after the first two letters of Henrietta Lacks first and last name. 

• CaSki Cell Line: a human epithelial cell line derived from the cervical tissue of a 40-year-old White female patient diagnosed with epidermoid carcinoma of the cervix. 
• This cell line serves as an important experimental model for investigating cervical cancer, especially in studies focused on oncogenesis driven by human papillomavirus (HPV).
• A key feature of CaSki cells is their ability to replicate HPV16 DNA, which is integrated into the cellular genome. 
• This integration allows researchers to examine how HPV16 contributes to malignant transformation, providing valuable insights into the viral life cycle, mechanisms of viral persistence, and the molecular pathways involved in HPV-associated cervical cancer development.

In contrast, they have very little effect on C-33A cells12, a commonly used cervical cancer cell line that does not contain HPV.

• C-33A (or C-33 A) cells are a human cervical squamous carcinoma cell line, commonly used in laboratory research to study cancer development. 
• Isolated from a 66-year-old Caucasian female in the 1960s, these cells are distinctive because they are HPV-negative, making them a crucial model for studying cervical cancer that develops without HPV infection.

This selective action indicates that the probiotic components preferentially attack cells transformed by the virus, rather than harming all cells indiscriminately.

For many of us, human breast milk has long been viewed simply as nourishment for a baby. 

But in truth, it is so much more than that.

Within every drop is a delicate, microscopic world, filled with components that show probiotic potential, as well as antimicrobial and anticancer properties.

Its unique ability to influence important microbial and cancer-related pathways opens the door to something quietly powerful and deeply hopeful.

What we once thought of as “just milk” is, in fact, a moving reflection of the body’s natural wisdom and care.

And within it, there is genuine hope for new, compassionate, and life-enhancing health solutions.

Author’s Note

Happy Mother’s Day to all the incredible mothers out there. 

This is (Part 3) In‑House Research: The Therapeutic Potential of Probio87 of a 3-part series, created to gently celebrate the quiet, often unseen sacrifices of motherhood, while shining a light on the properties of human breast milk—its daily, behind-the-scenes miracles that nourish, protect, and sustain life in the most remarkable ways.

May these stories wrap around your heart and encourage you to love more deeply—both those closest to you and those beyond your immediate circle. 

P.S. And if you can, give your mama a big, warm hug, on behalf of all of us at Probionic, and let her know how deeply she is seen, valued, and loved.

Read more: Part 1 | Part 2