Antioxidant Mechanisms of Probiotic Microorganisms

Oxidative stress arises when reactive oxygen species (ROS) overwhelm an organism’s native defence systems, leading to damage of lipids, proteins and nucleic acids. Probiotic microorganisms counteract this imbalance through multiple, often complementary, mechanisms. Certain Lactobacillus and Bifidobacterium strains express enzymes analogous to superoxide dismutase and catalase, directly neutralising ROS. Others synthesise glutathione or its precursors, replenishing intracellular thiol pools and reinforcing host antioxidant capacity. Secreted metabolites such as short-chain fatty acids support epithelial integrity and modulate inflammatory signalling. By activating host transcription factors—most notably nuclear factor erythroid 2-related factor 2 (Nrf-2)—probiotics upregulate key cytoprotective genes, including those for glutathione S-transferase and heme oxygenase-1. Metal-ion chelation, inhibition of prooxidant enzymes and reinforcement of tight junction proteins further reduce oxidative injury in the gut mucosa. Evidence spans in vitro radical-scavenging assays, animal models of hepatic and intestinal damage and human trials measuring plasma antioxidant indices. Exploiting these mechanisms holds promise for developing functional foods, synbiotics and therapeutic strategies to prevent or mitigate chronic diseases linked to oxidative stress.

Research from Nature Portfolio

No recent Nature Portfolio content available.

Antioxidant Mechanisms of Probiotic Microorganisms publication trend

The graph below shows the total number of articles in antioxidant mechanisms of probiotic microorganisms across all publications each year (not limited to Nature Index journals).

Technical terms

Reactive oxygen species (ROS): Chemically reactive molecules containing oxygen that can damage cellular components when present in excess.

DPPH assay: A chemical test measuring a sample’s capacity to donate electrons or hydrogen atoms to the DPPH radical, indicating radical-scavenging activity.

ABTS assay: An antioxidant assay that quantifies the ability to quench the ABTS radical cation, reflecting total antioxidant capacity.

Short-chain fatty acids (SCFAs): Fatty acids with fewer than six carbon atoms, produced by microbial fermentation, that support gut barrier function and systemic antioxidant defences.

Nuclear factor erythroid 2-related factor 2 (Nrf-2): A transcription factor that, upon activation, induces expression of antioxidant and cytoprotective genes.

References

1. Antioxidant Properties of Probiotic Bacteria. Nutrients (2017).
2. Oxidative stress tolerance and antioxidant capacity of lactic acid bacteria as probiotic: a systematic review. Gut Microbes (2020).
3. Antioxidant Activity and Probiotic Properties of Lactic Acid Bacteria. Fermentation (2022).
4. Lactic Acid Bacteria With Antioxidant Activities Alleviating Oxidized Oil Induced Hepatic Injury in Mice. Frontiers in Microbiology (2018).
5. Probiotics Prevent Intestinal Barrier Dysfunction in Acute Pancreatitis in Rats via Induction of Ileal Mucosal Glutathione Biosynthesis. PLOS ONE (2009).
6. Evaluation of the functional efficacy of an antioxidative probiotic in healthy volunteers. Nutrition Journal (2005).
7. The Potential of Lactobacillus spp. for Modulating Oxidative Stress in the Gastrointestinal Tract. Antioxidants (2020).