Reuterin

Reuterin is a broad-spectrum antimicrobial substance produced by certain strains of Lactobacillus reuteri bacteria. Chemically, it is primarily β-hydroxypropionaldehyde (3-hydroxypropionaldehyde, 3-HPA), existing in equilibrium with its hydrate form.

Production and Mechanism:

Reuterin is synthesized from glycerol under anaerobic conditions by L. reuteri strains possessing the glycerol dehydratase enzyme. Glycerol, often found in the gut environment, is converted to 3-HPA. The antimicrobial activity is attributed to its ability to inhibit several enzymes, particularly those involved in DNA synthesis and energy metabolism within susceptible microorganisms. It can also interact with cell membranes, disrupting their integrity.

Antimicrobial Spectrum:

Reuterin exhibits a broad antimicrobial spectrum, effective against Gram-positive and Gram-negative bacteria, yeasts, fungi, and protozoa. Its inhibitory effects have been demonstrated against common pathogens like Escherichia coli, Salmonella spp., Staphylococcus aureus, and Candida albicans. The exact sensitivity varies depending on the target organism and the concentration of reuterin.

Biological Significance and Applications:

Reuterin plays a significant role in the competitive exclusion of undesirable microorganisms in the gastrointestinal tract, contributing to gut health and balance. The production of reuterin by L. reuteri is believed to be a key factor in the probiotic effects associated with these strains.

Potential applications of reuterin, or L. reuteri strains producing it, include:

• Probiotics: L. reuteri strains producing reuterin are used as probiotics to promote gut health and combat infections.
• Food Preservation: Reuterin has potential as a natural food preservative to inhibit the growth of spoilage microorganisms.
• Antimicrobial Therapy: Research is ongoing to explore the potential of reuterin as a therapeutic agent against various infections, although further studies are needed.

Stability and Regulation:

Reuterin is relatively stable at acidic pH and at temperatures typically encountered in the gastrointestinal tract. However, it is susceptible to degradation under alkaline conditions and at high temperatures. The production of reuterin by L. reuteri is influenced by factors such as glycerol concentration, pH, and the presence of other microorganisms.

Further Research:

Ongoing research focuses on optimizing reuterin production, understanding its mechanisms of action in greater detail, and exploring its potential applications in various fields, including medicine, food science, and agriculture.