Probiotic Applications in Immunomodulation and Neuroprotection

Probiotics, live microorganisms that confer health benefits when administered in adequate amounts, have emerged as versatile agents capable of modulating immune function and safeguarding neural integrity. In the context of immunomodulation, specific probiotic strains and their secreted metabolites interact with intestinal and systemic immune cells to promote balanced cytokine production, enhance barrier function and attenuate excessive inflammation. Parallel advances have revealed a critical role for the gut–brain axis, wherein microbial signals influence neuronal survival, neuroinflammation and synaptic plasticity. Neuroprotective mechanisms attributed to probiotics include antioxidant activity, reduction of reactive oxygen species, up-regulation of brain-derived neurotrophic factor and modulation of microglial activation. This dual capacity to regulate immune responses and directly support neural cells underscores the global significance of probiotics in preventing and treating disorders ranging from autoimmune diseases to neurodegenerative conditions. Emerging clinical and preclinical studies illustrate practical applications, from dietary supplements to functional foods, highlighting the translational potential of tailored probiotic interventions in maintaining immune homeostasis and promoting brain health.

Research from Nature Portfolio

A seminal investigation explored the neuroprotective potential of Ruminococcus albus in models of oxidative stress. Conditioned medium derived from intestinal epithelial cells exposed to heat-killed R. albus enhanced expression of brain-derived neurotrophic factor and cell proliferation markers in neuronal cultures, while reducing apoptotic signalling by decreasing the Bax/Bcl-2 ratio. Oral administration in animal models attenuated cerebral oxidative damage, lowered reactive oxygen species levels and boosted endogenous antioxidant enzymes such as superoxide dismutase and glutathione peroxidase. These findings established a mechanistic link between probiotic-stimulated epithelial secretions and direct neuronal protection, offering a foundational paradigm for gut-based interventions in neurodegenerative diseases.

Probiotic Applications in Immunomodulation and Neuroprotection publication trend

The graph below shows the total number of articles in probiotic applications in immunomodulation and neuroprotection across all publications each year (not limited to Nature Index journals).

Technical terms

Probiotic: Live microorganism that, when administered in adequate amounts, confers a health benefit on the host.

Immunomodulation: The alteration of immune responses through enhancement or suppression of specific pathways.

Neuroprotection: Preservation of neuronal structure and function against injury or degeneration.

Conditioned medium (CM): Culture fluid collected from cells after exposure to a treatment, containing secreted factors.

Extracellular vesicles (ECVs): Membrane-bound particles released by cells that carry proteins, lipids and nucleic acids.

Reactive oxygen species (ROS): Chemically reactive molecules containing oxygen that can cause cellular damage.

Brain-derived neurotrophic factor (BDNF): Protein that supports neuron survival, growth and synaptic plasticity.

Nuclear factor κB (NF-κB): Transcription factor regulating genes involved in immune and inflammatory responses.

Mitogen-activated protein kinases (MAPKs): Enzymes mediating intracellular signalling cascades in response to extracellular stimuli.

References

1. Probiotic Properties of Loigolactobacillus coryniformis NA-3 and In Vitro Comparative Evaluation of Live and Heat-Killed Cells for Antioxidant, Anticancer and Immunoregulatory Activities. Foods (2023).
2. Neuroprotective effect of Ruminococcus albus on oxidatively stressed SH-SY5Y cells and animals. Scientific Reports (2017).
3. Immunostimulatory Activity of Lactic Acid Bacteria Cell-Free Supernatants through the Activation of NF-κB and MAPK Signaling Pathways in RAW 264.7 Cells. Microorganisms (2022).
4. Immunomodulatory Activity of Extracellular Vesicles of Kimchi-Derived Lactic Acid Bacteria (Leuconostoc mesenteroides, Latilactobacillus curvatus, and Lactiplantibacillus plantarum). Foods (2022).