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ingestible · for oral health & dental care

Lactobacillus reuteri Probiotic

Reviewed by the Nimbera editorial team · Last updated May 2026

Krasse 2006 Swed Dent J (PMID 16878680) - double-blind RCT in 59 patients with moderate-to-severe gingivitis; both L. reuteri formulations (2x10^8 CFU/day) significantly reduced gingival index vs placebo (p < 0.0001) over 2 weeks.$25-$40 for a 30-day supply of lozenges

How to use

Take one L. reuteri lozenge or chewable tablet (containing strains DSM 17938 and ATCC PTA 5289, 2x10^8 CFU total) twice daily for at least 4-12 weeks as an adjunct to normal brushing and flossing. Let the lozenge dissolve slowly in the mouth rather than swallowing immediately so the bacteria can colonize oral surfaces.

How it works

L. reuteri competes with periodontal pathogens such as Porphyromonas gingivalis and Treponema denticola for binding sites on oral surfaces (competitive exclusion). It also produces antimicrobial compounds including reuterin and organic acids, and modulates local immune responses to reduce pro-inflammatory cytokines that drive gingival tissue destruction.

Where to buy

BioGaia Prodentis oral lozenges contain both DSM 17938 and ATCC PTA 5289 strains and are the most clinically studied product. Available at iHerb, Amazon, and specialist health retailers. Ensure the product is specifically formulated for oral use - gut probiotic strains are not equivalent.

Typical cost: $25-$40 for a 30-day supply of lozenges

Safety notes

Generally very well tolerated. Immunocompromised individuals should consult a physician before using any live probiotic. Effectiveness depends on consistent daily use; benefits diminish after discontinuation. Not a substitute for scaling and root planing in established periodontitis.

Drug & supplement interactions

  • Always tell your doctor or pharmacist about any supplements you take.
  • Interactions can occur with prescription medications, blood thinners, and immunosuppressants.
  • Herbal remedies can affect how the body absorbs or metabolises drugs.
  • Check drugs.com interactions checker before starting.

Clinical source

Krasse 2006 - Swed Dent J (PMID 16878680)

This information is compiled from primary clinical literature and is for informational purposes only. It is not a substitute for professional medical advice. Read our full disclaimer.