An Amino Acid that May Prevent Decay: L-Arginine

L-arginineSo there are ingredients to steer clear of in our toothpastes, such as the triclosan we looked at last week. Others, such as probiotics, we might embrace.

Another one of the apparent good guys? L-arginine.

L-arginine is an amino acid found protein-rich foods such as meat and dairy, as well as nuts, seeds, beans, and oats. It helps improve blood flow by creating nitric oxide. It regulates blood pressure. It helps your kidneys remove waste and helps your body heal from injury. It boosts immune function.

It’s also been known to reduce tooth sensitivity, and, it turns out, it may help reduce oral biofilms, too – a/k/a/ plaque.

Keep in mind that no matter how well you brush and floss, both helpful and harmful bacteria remain in your mouth. As soon as you’re done cleaning, pathogens such as S. mutans go right back to work, forming new biofilms: microbial colonies bound together by a sticky substance they secrete. This helps protect the pathogens, allowing them to thrive – at least until they’re disrupted again by your cleaning.

Or, it seems, until L-arginine gets involved, according to a 2015 study in PLoS ONE. At high concentrations, it was found “to make biofilm fall apart,” as one of the study authors put it. Because the amount needed for this effect is much higher than you could get through diet alone, the authors suggested there could be some benefit from putting it in products such as toothpaste and mouthwash.

Another study, published earlier this year in Applied and Environmental Microbiology, found that L-arginine specifically inhibits S. mutans.

We find that arginine negatively impacts the growth, the pathogenic potential, and the tolerance of environmental stresses in a way that is likely to compromise the ability of S. mutans to cause disease.

Meanwhile, recent research in the Archives of Oral Biology found that while L-arginine didn’t appear to affect bacterial growth all that much, it did inhibit the formation of biofilms generated by S. mutans. The authors suggest that this might be “due to the impact of [L-arginine] on water-insoluble [exopolysaccharide]” – the sticky stuff holding the colonies together.

Others have found that L-arginine seems to improve oral pH regulation. This is critical since oral pathogens thrive in acidic conditions. But researchers have found that biofilms treated with L-arginine recovered to a more alkaline state. More,

Sequencing analysis revealed a shift in the microbial community structure in arginine-treated biofilms as well as increased species diversity. Overall, we show that arginine improved pH homeostasis through a remodeling of the oral microbial community.

Right now, there aren’t a lot of toothpastes that contain L-arginine, but we expect to see more if the scientific evidence continues to be so positive. Most currently available products are marketed as being for sensitive teeth, though we’ve only found one brand that’s both fluoride-free and SLS-free: Biomed Sensitive, which is available through Amazon and other sellers both in the US and abroad.

Already using a paste with L-arginine? Let us know about it in the comments!