Siphoviridae

Siphoviridae (LL5-Siphoviridae) as a Dietary Supplement Ingredient: A Reference Article

Preliminary Clarification: Taxonomic Identity and Supplement Context

Multiple supplement ingredient databases note explicitly that "Siphoviridae is not an ingredient in nutritional products or herbal remedies" in the conventional botanical or chemical sense. Rather, Siphoviridae is a family of bacteriophages—viruses that infect bacteria—widely studied in microbiology and biotechnology. The term appears on dietary supplement labels specifically in the form of the strain designation LL5-Siphoviridae, a component of the commercially available phage blend PreforPro®. This article covers Siphoviridae bacteriophages as they exist within the dietary supplement context, using LL5-Siphoviridae and the PreforPro® cocktail as the primary subjects of discussion, since these represent the only clinically studied supplemental application of Siphoviridae phages.

Furthermore, an important taxonomic development must be noted at the outset: as a result of the abolishment of morphology-based taxa, the iconic families Myoviridae, Siphoviridae and Podoviridae with the order Caudovirales have now been removed from the current International Committee on Taxonomy of Viruses (ICTV) classification system. While the family designations were useful for a period of time, the ability to rapidly sequence phage genomes and classify phages based on genomic content rather than morphology offers more resolution to describe differences; nevertheless, the morphotypes of Myovirus, Podovirus, and Siphovirus live on in the scientific and supplement literature. The name "LL5-Siphoviridae" on supplement labels reflects the older morphology-based classification system that was standard when these products were developed and first studied.

Identity and Classification

Biological and Scientific Name

LL5-Siphoviridae is a bacteriophage (virus that infects bacteria) belonging to the Siphoviridae family, a group of phages characterized by their long, non-contractile tails and double-stranded DNA genomes. The broader family from which LL5 takes its name was historically defined by structural criteria: in the former ICTV taxonomy, the division of the order Caudovirales into three families was based solely on tail morphology: members of the family Siphoviridae have long non-contractile tails, Myoviridae have long contractile tails, and Podoviridae have short tails.

The name itself is etymologically descriptive: Sipho derives from the Greek siphon, meaning "tube," referring to the long tail.

In general, Siphoviridae phages are known to possess double-strand (ds) DNA genomes. Structurally, representative Siphoviridae virions have been characterized as having specific head-and-tail architecture: one characterized phage in the patent literature showed morphological classification into the family Siphoviridae and order Caudovirales, with tail length and width of 129 ± 7 nm and 14 ± 2 nm respectively, and a head diameter of 63 ± 6 nm.

The prototype and most extensively studied member of the former Siphoviridae family is bacteriophage lambda (λ): lambda phage belongs to the Siphoviridae family of the order Caudovirales, defined by the lack of envelope, non-contractile tail, and a linear double-stranded DNA molecule; it has been studied for various purposes to understand lytic and lysogenic lifestyles of various viruses and also as a model virus for viral studies; the virus has a temperate life cycle that enables it to either enter the lytic phase or reside within the host's genome via lysogeny.

Natural Source

Bacteriophages, including members of the Siphoviridae morphotype, are among the most abundant biological entities on Earth. Bacteriophages are viruses that infect and replicate within bacteria; they are the most diverse and abundant biological entities on the planet, and they play an important role in controlling populations of bacteria that they exploit and kill. Phages are isolated from natural environmental sources—including soil, water, fermented foods, and the gut itself—using bacterial host cultures, then purified and characterized for supplemental use.

The specific strain LL5-Siphoviridae used in dietary supplements is studied for its specificity against E. coli strains, and potentially other Enterobacteriaceae, with applications in bacterial pathogen control, phage therapy, gut microbiome modulation, and probiotic support.

Supplement Forms and Commercial Preparations

In the supplement marketplace, LL5-Siphoviridae is not sold as a standalone ingredient. In the supplement industry, LL5 is rarely sold on its own; it is most famously known as one of the four critical phage strains in PreforPro®, a patented and clinically studied bacteriophage blend designed to optimize the human microbiome.

PreforPro is a commercially available bacteriophage cocktail designed to modulate the gut microbiota; it contains a blend of bacteriophages, including LH01-Myoviridae, LL5-Siphoviridae, T4D-Myoviridae, and LL12-Myoviridae, which target specific bacteria within the gut, such as E. coli. It is available in various supplement forms, most commonly capsules, and is intended to support overall gut health by selectively targeting and reducing harmful bacteria.

PreforPro is manufactured by Deerland Probiotics and Enzymes (Kennesaw, Georgia, USA) and has been incorporated into several commercial synbiotic and prebiotic products. For example, one commercially available product lists PreforPro® (LH01-Myoviridae, LL5-Siphoviridae, T4D-Myoviridae, LL12-Myoviridae) at 15 mg per serving alongside probiotic strains.

Traditional and Historical Use

Discovery of Bacteriophages

Frederick William Twort and Felix d'Hérelle independently discovered bacteriophages in 1915 and 1917, respectively. Whilst studying the smallpox vaccine virus, Twort noticed that some bacterial colonies became glassy, transparent and stopped growing; he found that even after passing this through a porcelain filter small enough to trap bacteria, it still remained; he proposed three possible explanations—an enzyme, a self-replicating virus, or a product of bacterial metabolism—and leaned towards the virus hypothesis, publishing his work in the Lancet in 1915.

The concept of phage therapy emerged in the early 20th century with the discovery of bacteriophages by Félix d'Hérelle in 1917; d'Hérelle's observation that these viruses could effectively lyse bacteria in infected patients marked a pivotal moment in medical microbiology. While investigating outbreaks of dysentery among soldiers, d'Hérelle observed that filtrates from recovering patients could kill Shigella dysenteriae; he concluded this was due to a virus that infects bacteria, which he named "bacteriophage" (literally "bacteria-eater"); d'Hérelle immediately began therapeutic trials using phages to treat dysentery and cholera in India, publishing extensively and publicizing his results.

Early Therapeutic Use

Shortly after the discovery of bacteriophages, d'Hérelle attempted to apply them to the treatment of dysentery; in 1919, this research was carried out at the Hôpital des Enfants-Malades in Paris, under the clinical guidance of Professor Victor Henri Hutinel; to verify the safety of the bacteriophage preparation, d'Hérelle, Hutinel, and several hospital interns took the phage preparation themselves before administering it to a 12-year-old boy suffering from severe dysentery.

During the 1920s and 1930s, phage therapy spread rapidly across the world as researchers and physicians began using bacteriophages to treat a range of bacterial infections, including dysentery, cholera, and staphylococcal skin infections. This pioneering work led to early phage therapy trials for diseases such as typhoid fever and cholera in the 1920s, establishing a foundation for exploring phage therapy as an innovative approach to treating bacterial infections.

Soviet and Eastern European Traditions

Felix d'Hérelle proposed the use of bacteriophages for the therapy of human and animal bacterial infections at the beginning of the 20th century; however, this approach was not widely accepted in the West. After the emergence of antibiotics in the 1940s, phage research was diverted to a more fundamental level; at the same time, phage therapy was widely practiced in the Soviet Union due to collaboration of Felix d'Hérelle with his Georgian colleagues.

The old Soviet literature indicates that phage therapy was used extensively to treat a wide range of bacterial infections in the areas of dermatology, ophthalmology, urology, stomatology, pediatrics, and otolaryngology. Historically, bacteriophages like those from the Siphoviridae family have played a vital role in food safety and preservation, especially in Eastern Europe and Russia, where phage therapy has been used for decades to manage bacterial infections.

The earliest reported use of bacteriophages therapeutically in the United States was in 1922; with the subsequent discovery of antibiotics in the 1940s, and because of disappointing results of phage therapy in the next decade, use of bacteriophages as therapeutic agents declined in western countries.

Modern Revival and Supplement Context

Throughout history, bacteriophages, including members of the Siphoviridae family, have been explored for their medicinal potential, particularly in the field of phage therapy; in the early 20th century, before the widespread use of antibiotics, phage preparations were used therapeutically. The modern application of Siphoviridae phages in dietary supplements represents a new chapter of this history, specifically reframing phages not as therapeutic drug agents but as microbiome-modulating ingredients classified within the functional food and dietary supplement category.

Growing concerns about the use of antibiotics have led to a resurgence of interest in bacteriophage as an alternative to antibiotics. The formulation of PreforPro® (containing LL5-Siphoviridae) in the 2010s reflects this revival, with the specific goal of leveraging phage selectivity for gut health applications rather than anti-infective therapy.

Key Constituents and Active Compounds

Virion Structure

Siphoviridae phages (now classified under various new family names in current ICTV taxonomy) share a conserved head-and-tail architecture. The Siphoviridae possess long noncontractile tails, in contrast to Myoviridae which have contractile tails and Podoviridae which have short noncontractile tails. The protein capsid (head) houses the phage's double-stranded DNA genome, and the tail apparatus is responsible for host recognition and DNA injection.

The genomic and structural properties of Siphoviridae phages vary among genera and species. Genomes of some characterized Siphoviridae are approximately 22 kbp with a G+C content of 35–40%. The virion's structural proteins include multiple polypeptides at various molecular weights; for example, virions of one characterized genus have at least six structural proteins ranging from 19.2 to 175 kDa, with major proteins at 29, 90, and 175 kDa.

Lytic vs. Lysogenic Life Cycles

A critical feature of many Siphoviridae phages relevant to their supplement application is their capacity for both lytic and lysogenic cycles. Unlike members of the Myoviridae family (which often exhibit rapid lytic behavior), Siphoviridae phages like LL5 may exhibit temperate behavior, meaning they can either lyse their host bacteria or integrate their genome into the host's DNA in a lysogenic cycle, depending on environmental signals and genetic programming.

In the lytic cycle: the phage replicates and lyses the host cell. In the lysogenic cycle: phage DNA is incorporated into the host genome, where it is passed on to subsequent generations; environmental stressors such as starvation or exposure to toxic chemicals may cause the prophage to excise and enter the lytic cycle.

An important concern about temperate phages in a supplement context is the phenomenon of lysogenic conversion: the presence of the phage may alter the phenotype of the bacterium, since it can bring in extra genes (e.g., toxin genes that can increase bacterial virulence); this change in the host phenotype is called lysogenic conversion or phage conversion. This is a safety-relevant consideration when selecting phage strains for supplemental use: LL5 can be engineered or selected for lytic-only activity, making it safer for clinical applications where integration of phage DNA into bacterial chromosomes would be undesirable.

Additionally, temperate phages can act as vehicles for horizontal gene transfer, a process called transduction: phages can act as powerful agents of microbial adaptation and evolution by means of their ability to transfer bacterial DNA (encoding virulence factors and antibiotic resistance) from one bacterium to another by a process known as genetic transduction. This property is a consideration in safety assessments of phage supplements, as phages used in foods and supplements should ideally lack genes encoding virulence factors or antibiotic resistance.

Mechanism of Antibacterial Action

The mechanism by which LL5-Siphoviridae and related phages exert their selective effects in the gut is through highly specific receptor-mediated bacterial targeting. Bacteriophages are naturally occurring viruses that infect and kill bacteria, thereby influencing the gut's ecological balance. The phage uses its tail fibers to recognize and attach to specific receptors on the surface of target bacteria, inject its DNA, and hijack bacterial cellular machinery to produce new phage particles, ultimately destroying the target bacterium.

This specificity is what makes Siphoviridae phages attractive for microbiome applications: these bacteriophages are considered safe for human consumption and they specifically target the pathogenic bacteria of the gut and allow the populations of beneficial bacteria to increase. The selective elimination of competing bacteria, particularly E. coli strains, is proposed to free ecological "space" in the gut for beneficial bacteria such as Lactobacillus and Bifidobacterium species to expand.

Scientific Evidence by Area of Use

Gut Microbiome Modulation

Evidence level: Preliminary human clinical data (small RCTs), supported by in vitro and animal data.

The most direct clinical evidence for LL5-Siphoviridae as a supplement ingredient comes from the PHAGE Study (Bacteriophage for Gastrointestinal Health), conducted at Colorado State University. The Bacteriophage for Gastrointestinal Health (PHAGE) study done by Tiffany Weir at Colorado State University determined the tolerability and safety of the supplemental consumption of bacteriophage in a healthy adult population with mild to moderate gastrointestinal distress.

The study was conducted as a randomized, double-blind, placebo-controlled crossover intervention trial, with two 28-day intervention periods and a washout period of at least two weeks between treatments; the treatments consisted of 4 supplemental bacteriophage strains (LH01-Myoviridae, LL5-Siphoviridae, T4D-Myoviridae, and LL12-Myoviridae) at a titer of 10⁶ phages per dose included in PreforPro® commercial capsules prepared by Deerland Enzymes. Participants were asked to consume one 15 mg capsule per day during the treatment and placebo periods.

The new study involved 43 participants aged 18 to 65 randomly assigned to receive the Escherichia coli-targeting bacteriophages (LH01-Myoviridae, LL5-Siphoviridae, T4D-Myoviridae, and LL12-Myoviridae) or placebo for 28 days, followed by a minimum two-week "washout" period before crossing over to the other intervention group.

Results: PreforPro consumption led to significant decreases in E. coli and significant decreases in the proportion of taxa closely related to Clostridium perfringens; on the other hand, 4–5-fold increases in populations of the genera Eubacterium were reported. The authors described the mechanism as offering "a novel and selective means of modifying the gut microbiota, thereby influencing the intestinal environment without causing global perturbations that can lead to microbial dysbiosis."

Along with previously published data, this study confirms the safety and tolerability of phage consumption in a human population; these data support further studies on the microbiota modulatory potential of bacteriophages for use as a dietary supplement and possibly as a therapeutic agent in clinical populations of intestinal inflammation.

Limitations: The PHAGE study involved only 43 participants and used a crossover design; the small sample size limits generalizability. Additionally, the entire PreforPro cocktail (four phage strains) was used, making it impossible to attribute effects specifically to LL5-Siphoviridae alone versus the other three strains. The study was also funded by Deerland, the manufacturer of PreforPro.

Combined Probiotic and Phage Supplementation (PHAGE-2 Study)

Evidence level: Preliminary human clinical data (small RCT), industry-funded.

The PHAGE-2 study, led by scientists from Colorado State University and funded by Deerland Probiotics and Enzymes, investigated if the combination of Bifidobacterium animalis subsp. lactis strain BL04 and its bacteriophage cocktail (LH01-Myoviridae, LL5-Siphoviridae, T4D-Myoviridae, and LL12-Myoviridae) could impact gastrointestinal health in 66 healthy participants.

A total of 68 participants were enrolled in a 4-week, randomized, parallel-arm, double-blind, placebo-controlled trial where primary outcomes included self-assessments of GI health, a daily stool log, and 16S rRNA analysis of gut microbial populations.

The three arms were: placebo (15 mg rice maltodextrin); 1 × 10⁹ Colony Forming Units (CFU) Bifidobacterium animalis subspecies lactis strain BL04; or 1 × 10⁹ CFU B. lactis BL04 + 1 × 10⁶ Plaque Forming Units (PFU) LH01-Myoviridae, LL5-Siphoviridae, T4D-Myoviridae, and LL12-Myoviridae bacteriophages, marketed as PreforPro. Participants were asked to consume one 15-mg capsule per day during the 4-week intervention period.

Results: Within-group improvements in GI inflammation (p = 0.01) and a trending improvement in colon pain (p = 0.08) were observed in individuals consuming B. lactis with PreforPro, but not in the group consuming only the probiotic; there was also a larger increase in Lactobacillus and short-chain fatty acid-producing microbial taxa detected in the stool of participants taking PreforPro with B. lactis compared to the probiotic alone; overall, these results suggest the addition of PreforPro as a combination therapy may alter gut ecology to extend the GI benefits of consuming B. lactis or other probiotics.

Limitations: This was an industry-funded trial with a small sample per arm. The positive effect was seen only in the combination arm, not in the phage-alone arm (no phage-only arm without probiotic was included). Clinical significance of the GI inflammation improvement requires further independent replication. The colon pain result did not reach statistical significance.

In Vitro and Animal Evidence

Probiotics containing phages have proven their effectiveness in in vitro cellular models and animal models; however, their efficiency has not been fully demonstrated in humans. Animal research has also explored Siphoviridae phages for specific pathogen control: for instance, a patent-filed bacteriophage STP-2, a Siphoviridae bacteriophage isolated from nature, has the ability to specifically kill Salmonella Typhimurium and was explored as an active ingredient in compositions for preventing and treating Salmonella-caused disease.

Recent scientific interest has focused on the capacity of Siphoviridae phages to target specific strains of undesirable bacteria in the digestive tract, potentially reducing harmful populations without disturbing beneficial microbes; some in vitro studies and animal models have indicated that these phages may help maintain gut microbial balance. However, these findings remain preclinical and should not be extrapolated to confirmed human benefits.

Gastrointestinal Inflammation

The PHAGE-2 study provided the primary human data on GI inflammation: results published in Nutrients indicated that the combination led to improvements in gastrointestinal inflammation compared to the group only receiving the probiotic; in addition, B. lactis with bacteriophages led to a larger increase in Lactobacillus and short-chain fatty acid-producing microbial taxa. Short-chain fatty acids such as butyrate are considered beneficial because of their role in maintaining intestinal barrier integrity and modulating inflammation.

Secondary outcome measures in the PHAGE clinical study design included determining changes in comprehensive metabolic profiles, inflammatory markers (systemic and local), microbial metabolites, and perceptions of gastrointestinal distress. Human evidence for anti-inflammatory effects of Siphoviridae-containing supplements remains limited to small, early-stage trials as of the current literature.

Antimicrobial Resistance Context

A broader area of interest for Siphoviridae and related phages is their potential utility against multidrug-resistant bacteria, particularly in clinical settings. Phage therapy has been considered and already used as an alternative treatment to manage infections caused by MDR pathogens, also recently in animals and humans against infections caused by MDR Acinetobacter baumannii. However, this clinical therapeutic use is distinct from supplement use and is not covered under dietary supplement regulatory frameworks.

Body Systems and Health Areas

• Gastrointestinal System: The primary target of Siphoviridae-based supplements is the gut microbiome. The human gastrointestinal tract is colonized by bacteria that constitute the intestinal microbiota; changes in the microbiota may lead to several chronic disorders. PreforPro® (containing LL5-Siphoviridae) targets E. coli populations in the gut, aiming to reduce competitive pressure on beneficial microbes.
• Immune System: PreforPro is primarily used to enhance the effects of probiotics, potentially improving gastrointestinal health by reducing inflammation and promoting the growth of beneficial bacteria. Short-chain fatty acid-producing bacteria that increase with phage supplementation are associated with immune regulation at the intestinal mucosa.
• Broader Microbiome-Linked Systems: Human gut microbiota and intestinal health are strongly interconnected and may lead to chronic systemic health diseases. The indirect effects of microbiome modulation on systemic health (metabolic, immune, neurological) are an area of active research, but specific human evidence linking LL5-Siphoviridae supplementation to outcomes beyond the gut is lacking.
• Urinary and Reproductive Health: The use of probiotics with bacteriophage is under investigation to improve urinary and vaginal health, though specific Siphoviridae-focused evidence in these areas is not yet available in the published clinical literature.

Dosage Forms and Reported Dosages

PreforPro is available in various supplement forms, most commonly capsules, and is intended to support overall gut health by selectively targeting and reducing harmful bacteria.

The dosages used in the published clinical trials are as follows:

• PHAGE Study (crossover RCT, n=43): Treatments consisted of 4 supplemental bacteriophage strains (LH01-Myoviridae, LL5-Siphoviridae, T4D-Myoviridae, and LL12-Myoviridae) at a titer of 10⁶ phages per dose; participants consumed one 15 mg capsule per day during the treatment period.
• PHAGE-2 Study (parallel RCT, n=68): The phage cocktail arm received 1 × 10⁶ Plaque Forming Units (PFU) of PreforPro combined with 1 × 10⁹ CFU of B. lactis BL04 per day; participants consumed one 15-mg capsule per day during the 4-week intervention period.
• Commercial formulations: One commercial synbiotic product lists PreforPro® at 15 mg per serving.

Dosage is expressed in both mass (milligrams of freeze-dried phage preparation) and biological activity units (PFU — Plaque Forming Units). The 15 mg capsule containing 10⁶ PFU total phage titer is the most consistently reported dose across published human studies. No dose-ranging studies for LL5-Siphoviridae specifically have been identified in the peer-reviewed literature.

Safety Considerations

General Safety Profile of Oral Bacteriophages

Clinical studies indicate that orally administered phages are well-tolerated, safe, and can reduce pathogen load while alleviating diarrheal symptoms, which supports the use of phages as a microbiome-sparing therapeutic strategy against gastrointestinal infections; oral phage delivery is generally considered safe due to the natural presence of bacteriophages in the human gastrointestinal tract.

According to the PHAGE study data, therapeutic consumption of a mixture with 4 bacteriophages shows both safety and tolerability in the targeted human population. This study, along with previously published data, confirms the safety and tolerability of phage consumption in a human population.

Regulatory Status

In the United States, the use of food additives, including bacteriophages, must be approved for use by the FDA prior to marketing unless such use is GRAS (Generally Recognized As Safe). Several bacteriophage products have received GRAS status for food applications: in August 2006, the United States Food and Drug Administration (FDA) approved using bacteriophages on cheese to kill Listeria monocytogenes bacteria, giving them GRAS status; in July 2007, the same bacteriophages were approved for use on all food products.

Also relevant: EBI Food System (Europe) developed a food additive for preventing food poisoning caused by Listeria monocytogenes, named Listex-P100, which is the first bacteriophage product approved by the US FDA; a phage-based product, LMP-102, was also developed as a food additive against Listeria monocytogenes, approved as GRAS.

Temperate Phage Concerns

A scientifically relevant safety consideration specific to Siphoviridae phages is their potential for lysogenic behavior. The presence of the phage may alter the phenotype of the bacterium, since it can bring in extra genes (e.g., toxin genes that can increase bacterial virulence); this change in the host phenotype is called lysogenic conversion; some bacteria such as Vibrio cholerae and Clostridium botulinum are less virulent in the absence of the prophage; the phages infecting these bacteria carry toxin genes in their genome and enhance the virulence of the host when the toxin genes are expressed.

This concern is relevant when selecting phage strains for supplemental use. Strains intended for supplement use should be thoroughly screened to ensure they do not carry genes encoding virulence factors or antibiotic resistance. Phages can act as powerful agents of microbial adaptation and evolution by means of their ability to transfer bacterial DNA (encoding virulence factors and antibiotic resistance) from one bacterium to another by a process known as genetic transduction, a fact that regulators and manufacturers must address in the characterization of any supplement-grade phage strain.

Reported Adverse Events in Clinical Studies

Comprehensive and standardized reporting of potential toxicities associated with phage therapy has generally been lacking in the published literature; structured safety and tolerability endpoints are necessary when phages are administered as anti-infective therapeutics. The PHAGE studies reported that no significant adverse events attributable to phage consumption occurred; participants tolerated the 15 mg daily dose without clinically meaningful disruption to their microbiome or blood chemistry profiles. Oral administration of bacteriophages was safe, well-tolerated, and did not cause any adverse clinical symptoms or significant changes in blood chemistry, as reported in phage supplement tolerability data.

Phage Resistance

A recognized scientific limitation for all phage-based interventions is the potential for target bacteria to develop resistance to the phage, which would reduce or eliminate its efficacy over time. This is an acknowledged limitation in the phage therapy literature and is considered a relevant challenge for supplement applications as well, though the supplement-focused human trials reviewed above did not report on this phenomenon specifically.

Lack of Standardized Interactions Data

No peer-reviewed publications have been identified that specifically characterize drug-phage or supplement-phage interactions for LL5-Siphoviridae. Research on PreforPro is still in its early stages, and initial clinical trials suggest promising benefits when used in conjunction with probiotics. The absence of interaction data should be noted as a gap in the existing evidence base.

Evidence Summary and Assessment

While definitive health benefits in humans have yet to be fully established, early results are promising. The current state of clinical evidence for LL5-Siphoviridae as a dietary supplement ingredient can be summarized as follows:

• Two small, randomized, double-blind, placebo-controlled clinical trials (PHAGE and PHAGE-2, conducted at Colorado State University, funded by the manufacturer Deerland) have examined the PreforPro® cocktail containing LL5-Siphoviridae.
• Both trials used the same formulation (15 mg capsule, 10⁶ PFU total) and a 28-day intervention period.
• Both trials demonstrated statistically significant reductions in gut E. coli populations and increases in certain beneficial microbial taxa.
• The PHAGE-2 study found improvements in GI inflammation markers and increases in short-chain fatty acid-producing bacteria when the phage cocktail was combined with a probiotic, but not with the probiotic alone.
• Probiotics containing phages have proven their effectiveness in in vitro cellular models and animal models; however, their efficiency has not been fully demonstrated in humans.
• All published clinical trials to date are industry-funded, small in sample size, and conducted by overlapping research groups, limiting independence of evidence.
• Effects attributable specifically to LL5-Siphoviridae cannot be isolated from the effects of the other three phage strains in the PreforPro® cocktail.

More research is needed to validate their clinical benefits, but current evidence supports their potential as a natural, precise tool for modulating gut flora and contributing to gastrointestinal wellness.

References

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