Lactobacillus / HO-1 Cancer Research Results

LA, Lactobacillus: Click to Expand ⟱
Features: Bacteria
Lactobacillus acidophilus: Gram-positive, homofermentative, anaerobic microbe
Lactobacillus johnsonii: probiotic bacteria found in the human body and fermented foods.
Lactobacillus Plantarum: probiotic bacterium that may help with inflammation, blood sugar

Lactobacillus crispatus
Lactobacillus rhamnosus

Lactobacillus — A group of Gram-positive, non-spore-forming, lactic-acid-producing bacteria widely present in fermented foods and in the human gastrointestinal and female reproductive microbiota. Many strains are used as probiotics, but biological and anticancer effects are highly species- and strain-specific rather than properties of the genus as a whole. Formal classification is a live microbial/probiotic modality rather than a conventional small-molecule drug. Common shorthand is Lactobacillus spp. or lactobacilli. Following the 2020 taxonomic revision, several historically named Lactobacillus species were reassigned; for example, Lactobacillus plantarum is now Lactiplantibacillus plantarum and Lactobacillus rhamnosus is now Lacticaseibacillus rhamnosus, whereas L. acidophilus, L. johnsonii, and L. crispatus remain within Lactobacillus. Anticancer evidence is strongest for modulation of the intestinal or cervicovaginal microenvironment and host immunity, with direct tumor-cell effects largely preclinical.

Primary mechanisms (ranked):

  1. Microbiome remodeling and epithelial-barrier support, including competitive exclusion of potentially pathogenic or pro-inflammatory organisms, production of lactic acid and antimicrobial metabolites, and improved tight-junction integrity.
  2. Antitumor immune modulation (strain-dependent), including dendritic-cell regulation, IL-12 signaling, CD8+ T-cell priming and tumor-infiltrating cytotoxic T-cell activity; Lactiplantibacillus plantarum L168-derived indole-3-lactic acid is a well-characterized experimental example.
  3. Suppression of chronic inflammatory signaling, including reduced pro-inflammatory cytokine and NF-κB-associated signaling in selected strains and models.
  4. Direct induction of cancer-cell apoptosis and growth arrest by strain-derived metabolites, cell-free supernatants or bacterial components, with ↑ BAX/caspases and ↓ BCL-2 reported in several colorectal and other cancer models.
  5. Modulation of tumor metabolism and hypoxic signaling, including HIF-1α, GLUT1 and glycolysis-related pathways in selected experimental systems; this is not established as a general Lactobacillus effect.
  6. Cervicovaginal ecological protection, particularly with L. crispatus, where Lactobacillus-dominant microbiota are associated with lower high-risk HPV persistence and cervical dysplasia risk; direct inhibition of HPV E6/E7 and cancer-cell proliferation has also been demonstrated in vitro.

Bioavailability / PK relevance: Classical plasma pharmacokinetics are not applicable to live Lactobacillus probiotics. Relevant exposure depends on viable CFU delivered, strain survival through storage and gastric/bile conditions, delivery site, mucosal adherence, transient colonization, baseline microbiota and production of local metabolites. Systemic bacterial exposure is neither required nor desirable. Some microbial metabolites can enter host circulation, but their exposure differs substantially among strains and individuals.

In-vitro vs systemic exposure relevance: Many anticancer experiments expose cultured tumor cells directly to concentrated bacterial supernatants, extracts, purified metabolites or live organisms. These conditions cannot be equated with plasma concentrations after oral probiotic administration. Effects should therefore be interpreted primarily as local gastrointestinal, mucosal or mechanistic evidence unless corresponding metabolite exposure has been demonstrated in vivo.

Clinical evidence status: Preclinical + small human/RCT adjunct evidence. Multiple randomized studies in colorectal-cancer surgery have reported improvements in intestinal barrier function, microbiota composition, bowel recovery or postoperative infectious complications from probiotic or synbiotic mixtures containing Lactobacillus strains. Human evidence does not establish Lactobacillus as a tumor-eradicating therapy or demonstrate improved cancer-specific survival. It should be considered a strain-specific supportive or investigational adjunct rather than an anticancer treatment. Use of live probiotics warrants caution in severely immunocompromised patients, critically ill patients and patients with central venous catheters because rare Lactobacillus bacteremia or sepsis has been documented.

Lactobacillus Mechanistic Profile

Rank Pathway / Axis Cancer Cells Normal Cells Primary Effect Notes / Interpretation
1 Microbiome and epithelial barrier ↓ tumor-supportive dysbiosis indirectly ↑ barrier integrity
↑ microbial homeostasis		 Reduces intestinal inflammation, pathogen translocation and disruption of epithelial tight junctions Strongest clinically relevant mechanism; highly strain- and site-dependent
2 CD8 T-cell antitumor immunity ↓ tumor growth indirectly ↑ dendritic-cell IL-12
↑ CD8+ T-cell activation		 Enhances antitumor immune surveillance Lactiplantibacillus plantarum L168-derived indole-3-lactic acid promotes IL12a expression and CD8+ T-cell function in colorectal-cancer models
3 Inflammatory signaling ↓ NF-κB-associated survival signaling (strain-dependent) ↓ excessive inflammatory signaling Reduces tumor-promoting chronic inflammation Direction varies substantially by species, strain, host tissue and immune context
4 Mitochondrial apoptosis ↑ BAX
↑ CASP3
↑ CASP9
↓ BCL-2		 ↔ or substantially less cytotoxicity in selected models Promotes intrinsic apoptotic cell death Mostly demonstrated using bacterial extracts or conditioned media at experimental concentrations
5 Cell cycle and proliferation ↓ proliferation
↑ cell-cycle arrest		 ↔ (model-dependent) Limits cancer-cell expansion Specific molecular targets differ markedly among strains and cancer types
6 HPV oncogenic signaling ↓ HPV E6/E7
↓ CDK2
↓ cyclin A
↑ p21		 ↔ protective cervicovaginal environment Suppresses HPV-associated cervical cancer-cell proliferation Reported particularly for supernatants from L. crispatus, L. jensenii and L. gasseri; largely preclinical
7 Cervicovaginal microbial ecology ↓ HPV persistence and carcinogenic environment indirectly ↑ Lactobacillus-dominant low-diversity microbiota Supports epithelial and microbial homeostasis L. crispatus is consistently more strongly associated with a favorable cervical environment than L. iners
8 HIF-1α and glucose metabolism ↓ HIF-1α
↓ GLUT1
↓ glycolytic adaptation (model-dependent)		 Not established May impair hypoxia-associated metabolic adaptation Reported in limited experimental models and should not be generalized across Lactobacillus strains
9 ROS and redox signaling ↑ or ↓ ROS (context-dependent) ↓ excessive oxidative stress in some inflammatory models Can participate in apoptosis or tissue protection depending on strain and model Not a uniform primary Lactobacillus mechanism; avoid assigning a single directional genus-level effect
10 Clinical Translation Constraint Strain effects cannot be extrapolated to the genus Rare bacteremia possible in high-risk hosts Limits translation of experimental anticancer findings Major constraints include strain identity, CFU viability, transient colonization, baseline microbiome heterogeneity, formulation differences, combined-species clinical trials and rare invasive infection in severely immunocompromised or critically ill patients


HO-1, HMOX1: Click to Expand ⟱
Source:
Type:
(Also known as Hsp32 and HMOX1)
HO-1 is the common abbreviation for the protein (heme oxygenase‑1) produced by the HMOX1 gene.
HO-1 is an enzyme that plays a crucial role in various cellular processes, including the breakdown of heme, a toxic molecule. Research has shown that HO-1 is involved in the development and progression of cancer.
-widely regarded as having antioxidant and cytoprotective effects
-The overall activity of HO‑1 helps to reduce the pro‐oxidant load (by degrading free heme, a pro‑oxidant) and to generate molecules (like bilirubin) that can protect cells from oxidative damage

Studies have found that HO-1 is overexpressed in various types of cancer, including lung, breast, colon, and prostate cancer. The overexpression of HO-1 in cancer cells can contribute to their survival and proliferation by:
  Reducing oxidative stress and inflammation
  Promoting angiogenesis (the formation of new blood vessels)
  Inhibiting apoptosis (programmed cell death)
  Enhancing cell migration and invasion
When HO-1 is at a normal level, it mainly exerts an antioxidant effect, and when it is excessively elevated, it causes an accumulation of iron ions.

A proper cellular level of HMOX1 plays an antioxidative function to protect cells from ROS toxicity. However, its overexpression has pro-oxidant effects to induce ferroptosis of cells, which is dependent on intracellular iron accumulation and increased ROS content upon excessive activation of HMOX1.

-Curcumin   Activates the Nrf2 pathway leading to HO‑1 induction; known for its anti‑inflammatory and antioxidant effects.
-Resveratrol  Induces HO‑1 via activation of SIRT1/Nrf2 signaling; exhibits antioxidant and cardioprotective properties.
-Quercetin   Activates Nrf2 and related antioxidant pathways; contributes to anti‑oxidative and anti‑inflammatory responses.
-EGCG     Promotes HO‑1 expression through activation of the Nrf2/ARE pathway; also exhibits anti‑inflammatory and anticancer properties.
-Sulforaphane One of the most potent natural HO‑1 inducers; triggers Nrf2 nuclear translocation and upregulates a battery of phase II detoxifying enzymes.
-Luteolin    Induces HO‑1 via Nrf2 activation; may also exert anti‑inflammatory and neuroprotective effects in various cell models.
-Apigenin   Has been reported to induce HO‑1 expression partly via the MAPK and Nrf2 pathways; also known for anti‑inflammatory and anticancer activities.
Scientific Papers found: Click to Expand⟱
8112- LA,    Metabolomics and proteomics reveal the inhibitory effect of Lactobacillus crispatus on cervical cancer
- in-vitro, Cerv, SiHa
HO-1↝, ACSL4↝, Ferroptosis↑, T-cadherin↑, ROS↑, lipid-P↑,

Showing Research Papers: 1 to 1 of 1

* indicates research on normal cells as opposed to diseased cells
Total Research Paper Matches: 1

Pathway results for Effect on Cancer / Diseased Cells:


Redox & Oxidative Stress(tgid=1) ⓘ

Ferroptosis↑, 1,   HO-1↝, 1,   lipid-P↑, 1,   ROS↑, 1,  

Core Metabolism/Glycolysis(tgid=4) ⓘ

ACSL4↝, 1,  

Cell Death(tgid=5) ⓘ

Ferroptosis↑, 1,  

Migration(tgid=13) ⓘ

T-cadherin↑, 1,  
Total Targets: 7

Pathway results for Effect on Normal Cells:


Total Targets: 0

Scientific Paper Hit Count for: HO-1, HMOX1
Query results interpretion may depend on "conditions" listed in the research papers.
Such Conditions may include : 
  -low or high Dose
  -format for product, such as nano of lipid formations
  -different cell line effects
  -synergies with other products 
  -if effect was for normal or cancerous cells

Filter Conditions: Pro/AntiFlg:%  IllCat:%  CanType:%  Cells:%  prod#:108  Target#:597  State#:%  Dir#:4
  wNotes=0  sortOrder:rid,rpid

 

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