Poly-γ-Glutamic Acid

Poly-γ-glutamic acid (γ-PGA) is a polymer produced by Bacillus bacteria, found naturally in natto (fermented soybeans). Used in skincare (hydration), food industry (texture), and has research interest for health applications. NO GRADED OUTCOMES - research is mostly preclinical. May have calcium absorption, immune, and antioxidant properties. Biodegradable and safe. Primarily used topically in cosmetics rather than as an oral supplement.

Quick Answer

What it is

Poly-γ-glutamic acid (γ-PGA) is a polymer produced by Bacillus bacteria, found naturally in natto (fermented soybeans). Used in skincare (hydration), food industry (texture), and has research interest for health applications.

Key findings

  • Grade D: Immune Function
  • Grade D: Probiotic Viability
  • Grade D: Antioxidant Status

Safety

No specific caution or interaction language was detected in the current summary/outcome notes.

ℹ️ Quick Facts: Poly-γ-Glutamic Acid

Quick Facts: Poly-γ-Glutamic Acid

  • Best Evidence:Grade D
  • Conditions Studied:2
  • Research Outcomes:7
  • Key Effect:Antioxidant Status
Outcomes by grade:
A0
B0
C0
D7
2 conditions · 7 outcomes

Detailed Outcomes

|
D
Immune Function
In preclinical studies, γ-PGA enhanced dendritic cell activation via TLR4 stimulation and dramatically inhibited tumor growth in tumor-bearing mice. As a vaccine adjuvant complexed with alum, it enhanced antigen delivery to lymph nodes and cross-protective immunity against H1N1 and H3N2 influenza strains in mice. A nanoparticle formulation with chitosan promoted pro-inflammatory cytokine production and T cell proliferation in vitro.
moderateImproves
D
Probiotic Viability
In vitro studies showed γ-PGA at 2.5% concentration significantly enhanced Bifidobacteria survival in fruit juices and protected bacteria in simulated gastric juice (pH 2.0) with less than 0.47 log CFU/ml reduction after 4 hours, versus free cell death within 2 hours. A separate study demonstrated γ-PGA with sodium alginate effectively protected Bifidobacterium species during freeze-drying.
moderateImproves
D
Gut Microbiota Composition
In a murine model, oral γ-PGA administration increased the abundance of beneficial Lactobacillales while reducing Clostridiales in the gut, demonstrating prebiotic potential through 16S rRNA gene sequencing analysis.
smallImproves
D
Glutamate and GABA Levels
In a study of 60 Sprague-Dawley rats, γ-PGA elevated serum glutamate and GABA concentrations in normal-weight rats, and increased brain glutamate across both normal and high-fat diet groups. Effects were diminished in diet-induced obese animals, suggesting metabolic status influences efficacy.
smallImproves
D
Gastrointestinal Protection
In vitro cell-based assays showed γ-PGA provided complete cytoprotective effects against oxidative damage in Caco-2 intestinal epithelial cells, suggesting potential gastrointestinal mucosal protection. These effects remained stable through simulated gastrointestinal digestion conditions.
smallImproves
D
Antioxidant Status
In an in vitro study, γ-PGA demonstrated 85.2% hydroxyl radical scavenging at 1 mg/mL, 94.1% superoxide anion radical scavenging, and 96.0% lipid peroxidation inhibition. It showed complete protective effects in Caco-2 intestinal cells against oxidative damage, with antioxidant capacity remaining stable through simulated digestion.
smallImproves
D
Bone Health
In 75 aged laying hens, dietary supplementation with γ-PGA combined with nanosized zinc oxide increased eggshell thickness and elevated serum mineral concentrations compared to conventional supplementation. Separately, the compound's known calcium-binding properties suggest potential for enhancing calcium absorption, though direct human evidence is lacking.
smallImproves

Evidence by Condition

Best grade per condition (each condition may have multiple outcomes)

Research Citations (11)

Antioxidant and gastrointestinal cytoprotective effect of edible polypeptide poly-γ-glutamic acid
(2020)
PMID: 32165198
Optimized production of poly(γ-glutamic acid) (γ-PGA) using Bacillus licheniformis and its application as cryoprotectant for probiotics
(2020)
PMID: 31880345
Poly-γ-Glutamic Acid Complexed With Alum Induces Cross-Protective Immunity of Pandemic H1N1 Vaccine
(2019)
PMID: 31354739
Chitosan/poly(γ-glutamic acid) nanoparticles incorporating IFN-γ for immune response modulation in the context of colorectal cancer
(2019)
PMID: 31233057
Prebiotic Effects of Poly-Gamma-Glutamate on Bacterial Flora in Murine Gut
(2017)
PMID: 27974732
Effects of nanosized zinc oxide and γ-polyglutamic acid on eggshell quality and serum parameters of aged laying hens
(2017)
PMID: 28771048
Poly(γ-glutamic acid), coagulation? Anticoagulation?
(2016)
PMID: 27545694
Infection-mimicking poly(γ-glutamic acid) as adjuvant material for effective anti-tumor immune response
(2015)
PMID: 25709015
Improving survival of probiotic bacteria using bacterial poly-γ-glutamic acid
(2015)
PMID: 25506798
Poly-γ-glutamic acid: production, properties and applications
(2015)
PMID: 25288645

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