Home Ingredients oraCMU® (Weissella cibaria CMU)

oraCMU® (Weissella cibaria CMU)

Weissella cibaria
Evidence Level
Limited
4 Clinical Trials
7 Documented Benefits
2/5 Evidence Score

oraCMU® (Weissella cibaria CMU) is a lactic acid bacterium isolated from the saliva of children with good oral health by researchers at Chonnam National University; the university's industry foundation holds the US patent naming strain CMU (KCTC 10650BP). It is made by OraTicx in Seoul, listed as OraPharm in earlier papers, and Stratum Nutrition is its sole North American distributor. It comes as a tablet that is slowly dissolved or chewed in the mouth, usually at bedtime after brushing, so the strain can act in the mouth rather than the gut. In placebo-controlled trials in Korean adults, self-rated breath improved after 8 weeks, and examiner-rated breath odor improved in one trial in people with gum inflammation. In adults without gum disease, most gum measures and plaque acid did not differ from placebo. All but one of the human trials had an author employed by the maker.

Studied Dose One 800 mg tablet sucked or chewed nightly after brushing for 8 weeks (100 million CFU per gram in one trial, per tablet in another); one 1 g, 200 million CFU tablet dissolved slowly twice daily for 8 weeks; or a 2 g, 200 million CFU powder sachet spread in the mouth twice daily for 4 weeks.
Active Compound Live Weissella cibaria strain CMU (patent deposit KCTC 10650BP), an oral lactic acid bacterium that in lab tests produces hydrogen peroxide and organic acids.

Benefits

Self-rated breath freshness in adults

In 100 adults with bad breath, one chewed tablet nightly for 8 weeks improved self-rated breath scores versus placebo, the trial's main outcome. Breath sulfur gases were lower at week 8 but were already lower at the start. In a trial of young adults, 23.5% on the probiotic vs 50% on placebo still felt they had bad breath after 8 weeks.

Supported by Trial 2, Trial 3

Breath odor judged by a trained examiner

In 80 adults with gum inflammation, two slow-dissolving tablets daily for 8 weeks lowered breath sulfur gases (the main outcome) and examiner-rated odor scores more than placebo by week 8, after adjusting for starting levels. That trial's authors noted that earlier oraCMU trials had not shown a placebo difference in examiner scores or sulfur gas changes.

Supported by Trial 3, Trial 2

Gum bleeding after a professional cleaning

In 92 adults aged 20 to 39 without periodontitis, one tablet nightly for 8 weeks after scaling reduced bleeding on probing more than placebo at upper-jaw cheek-side and tongue-side sites. Probing depth, gingival index and plaque index did not differ from placebo. This is a single trial whose first author works for the maker.

Supported by Trial 1, Trial 4

Gum measures studied in dental patients

In 80 adults with gingivitis or early periodontitis, gingival index and bleeding on probing improved more than placebo after 8 weeks; these are measures of a diagnosed gum condition and are reported as context. In 40 patients with inflamed gums around implants, 4 weeks of oraCMU powder spread in the mouth did not improve bleeding on probing more than placebo, the main outcome.

Supported by Trial 4, Trial 3

Mouth bacteria counts

In adults without periodontitis, Fusobacterium nucleatum and Staphylococcus aureus in the gum pocket were lower than placebo. In adults with gum inflammation, Porphyromonas gingivalis, Prevotella intermedia and Treponema denticola were lower, and W. cibaria levels rose. Bacterial counts are lab measures and do not on their own show a health change.

Supported by Trial 3, Trial 2

Acid production by dental plaque

In the 8-week trial of 92 adults (68 analyzed), a plaque acid test score fell in both the probiotic and placebo groups, with no difference between them. The trial checked whether a tablet held in the mouth adds to plaque acid; it did not, and it also did not lower plaque acid compared with placebo.

Supported by Trial 1, Trial 3

Oral health related quality of life

In young adults, an oral health quality of life score (OHIP-14) improved more with the probiotic than with placebo after 8 weeks, while depression and self-esteem scores did not differ. In the later 80-person trial, the same score improved within the probiotic group but did not differ from placebo.

Supported by Trial 1, Trial 3

Mechanism of action

1

Hydrogen peroxide and acids

In lab tests, most of the antibacterial effect of oraCMU culture fluid against gum bacteria depended on its acids and hydrogen peroxide. Researchers also found 19 secreted proteins, including an enzyme (N-acetylmuramidase) proposed to act against Porphyromonas gingivalis.

2

Settling in the mouth

The tablet is held in the mouth so the live strain can settle there. In the human trials, oral W. cibaria levels rose more in the probiotic groups than with placebo, which shows the strain was present in the mouth during use; how long it stays after stopping was not tested.

3

Inflammatory signals in gum cells (lab work)

In human gum fibroblasts exposed to gum bacteria, CMU lowered gene expression of the inflammatory messengers IL-6, IL-1beta, IL-8 and TNF-alpha and of the tissue enzymes MMP-1 and MMP-3, but only with direct cell contact. This lab work was done by the maker's employees.

4

Findings in dogs and rats (animal work)

In beagles, the higher dose lowered breath sulfur gases from week 4 and plaque index fell in both dose groups. In rats with induced gum inflammation, 14 days of CMU improved gum and plaque indices and lowered inflammatory markers. Animal results may not apply to people.

Clinical trials

1
Young adults after a dental cleaning: 8-week trial reported in four papers
PubMed

Randomized, double-blind, placebo-controlled trial at Kangwon National University, July to November 2018. After scaling, adults took one 800 mg tablet (oraCMU at 100 million CFU per gram, supplied by OraPharm) or placebo nightly after brushing for 8 weeks, letting it dissolve in the mouth. Breath, gum, plaque acid and questionnaire results were published as four papers under one ethics approval. The full texts read list Korean government funding; an OraPharm employee was an author of all four. (Kang et al. 2020, BMC Oral Health)

92 adults aged 20 to 39 without periodontitis and with breath sulfur gases of at least 1.5 ng/10 mL (49 probiotic, 43 placebo); 62 to 68 were analyzed in the different papers.

Bleeding on probing improved more than placebo at upper-jaw cheek-side and tongue-side sites; probing depth, gingival index and plaque index did not differ. F. nucleatum (weeks 4 and 8) and S. aureus (week 8) were lower. After 8 weeks, 23.5% vs 50% still reported bad breath, and oral health quality of life improved more; depression and self-esteem did not differ. Plaque acid scores fell in both groups with no difference. One mild dry mouth (probiotic) and one mild diarrhea (placebo) were judged unrelated.

2
Adults with bad breath: 8-week trial of a chewed tablet
PubMed

Randomized, double-blind, placebo-controlled trial at Seoul National University Dental Hospital. One 800 mg tablet with 100 million CFU of oraCMU (supplied by OraPharm) or placebo, chewed nightly after brushing for 8 weeks. The main outcome was a self-rated bad breath score; no examiner odor test was used. Funded by Korean government food research programs; no author lists a maker affiliation. (Han et al. 2023, Front Microbiol)

100 adults aged 20 to 70 with halitosis, 50 per group; 45 and 46 analyzed per protocol.

Self-rated bad breath scores differed from placebo at week 8 (p = 0.006) but not at week 4. Total sulfur gases were lower at week 8 (p = 0.017) but were already lower at baseline (p = 0.046); hydrogen sulfide plus methyl mercaptan, similar at baseline, was lower at week 8 (p = 0.012), yet the trial's model of change over time found no group difference in any sulfur gas measure. Oral W. cibaria levels rose. No safety issues were seen in adverse events or blood tests.

3
Adults with gum inflammation: 8-week trial reported in two papers
PubMed

Randomized, double-blind, placebo-controlled trial at Chosun University Dental Hospital, March 2024 to January 2025, registered retrospectively (KCT0009810). One 1 g tablet with 200 million CFU of oraCMU or an isomalt placebo, dissolved slowly twice daily after brushing for 8 weeks, supplied by OraTicx. Gum results appear in a companion paper, which names gingival index as its primary outcome (the breath paper names sulfur gases) and has a published correction whose content was not available. Funded by a Korean government program and a Chosun University research fund; an OraTicx employee was an author. (Lee et al. 2026, BMC Oral Health)

80 adults with gingivitis or stage I to II periodontitis, 40 per group; 77 completed after 3 placebo participants left for antibiotic use.

After adjusting for baseline, total sulfur gases (main outcome) fell more than placebo by week 8 (P = 0.001), as did examiner odor scores (P = 0.015) and self-rated breath (P = 0.045); unadjusted week 8 odor and self-rated scores did not differ (P = 0.131 and 0.096), and the probiotic group started with higher sulfur gas levels (not significant). Gingival index and bleeding on probing improved more than placebo; gingival index P = 0.035 (the breath paper's abstract misprints it as 0.0035). P. gingivalis, P. intermedia and T. denticola were lower. The OHIP-14 quality of life score did not differ between groups. No adverse events occurred.

4
Adults with inflamed gums around dental implants: 4-week exploratory trial
PubMed

Exploratory randomized trial with participants and examiner blinded. After scaling, patients spread a 2 g sachet of oraCMU powder (200 million CFU per sachet) or isomalt placebo over the inside of the mouth after morning brushing and at bedtime for 4 weeks, December 2022 to November 2023. Funded by hospital and national research grants; an OraTicx employee was an author. (Kim et al. 2026, Sci Rep)

44 patients with peri-implant mucositis enrolled; 40 analyzed, 20 per group.

The primary outcome, bleeding on probing, did not differ from placebo; only four participants per group had bleeding at the start. Overall bacterial diversity did not differ, though some subgingival species shifted, Probing depth, gingival index and plaque index did not differ from placebo overall; probing depth improved only in the moderate subgroup, in a post hoc analysis.

Side effects and drug interactions

Common Potential side effects

In the human trials, no safety issues were reported in adverse event records or blood tests; one trial recorded one mild dry mouth on the probiotic and one mild diarrhea on placebo, both judged unrelated.
The trials lasted 4 to 8 weeks in adults, so longer use, children and older adults with health conditions were not studied.
In maker-sponsored rat studies, 13 weeks at the highest dose tested caused no adverse effects, and genetic toxicity tests were negative.
In lab tests the strain resists kanamycin, a trait judged intrinsic to the species and not transferable to other bacteria.
As with any live probiotic, people who are severely immunocompromised or have heart valve disease should ask a doctor before use.

Important Drug interactions

Antibiotics can kill the live strain; in two trials, participants who needed antibiotics were dropped from the analysis.
Antibacterial mouth rinses or other oral care products were not allowed in several of the trials.
Immunosuppressant medicines: ask your prescriber before using any live probiotic.
Pregnancy and breastfeeding were not studied in the trials cited here; ask your doctor.

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Frequently asked questions about oraCMU® (Weissella cibaria CMU)

What is oraCMU and how is it taken?

oraCMU® (Weissella cibaria CMU) is a live bacterial strain first isolated from the saliva of children with good oral health. Unlike gut probiotics, it is taken as a tablet that is slowly dissolved or chewed in the mouth, usually at bedtime after brushing, so it can act in the mouth. Trials used about 80 to 400 million CFU a day for 4 to 8 weeks.

What did the breath studies find?

In two placebo-controlled trials, self-rated breath improved after 8 weeks. In one trial in adults with gum inflammation, a trained examiner also rated breath odor better than placebo and breath sulfur gases fell more. All the trials were in Korean adults, most were small, and most included an author employed by the maker.

Is oraCMU the same as other Weissella cibaria probiotics?

No. Probiotic effects are tied to the strain, and the trials on this page tested strain CMU only. Sister strains from the same research group, such as CMS1, are separate strains, and their results do not transfer to oraCMU or the other way round.

Is oraCMU safe to take?

No safety issues were reported in the 4 to 8 week adult trials, including blood tests in two of them, and rat studies at high doses found no adverse effects. Longer use, children and pregnancy were not studied. As with any live probiotic, people with a severely weakened immune system or heart valve disease should ask a doctor first.

What is oraCMU?

oraCMU® (Weissella cibaria CMU) is a lactic acid bacterium isolated from the saliva of children with good oral health by researchers at Chonnam National University; the university's industry foundation holds the US patent naming strain CMU (KCTC 10650BP).

What is oraCMU used for?

NutraSmarts does not list oraCMU under a health category. What the research covers: In 100 adults with bad breath, one chewed tablet nightly for 8 weeks improved self-rated breath scores versus placebo, the trial's main outcome. Breath sulfur gases were lower at week 8 but were already lower at the start.

What is the recommended dosage of oraCMU?

The clinically studied dose is One 800 mg tablet sucked or chewed nightly after brushing for 8 weeks (100 million CFU per gram in one trial, per tablet in another); one 1 g, 200 million CFU tablet dissolved slowly twice daily for 8 weeks; or a 2 g, 200 million CFU powder sachet spread in th… Always follow the product label and check with a healthcare provider for personal advice.

Does oraCMU interact with any medications?

Possible interactions include: Antibiotics can kill the live strain; in two trials, participants who needed antibiotics were dropped from the analysis. Antibacterial mouth rinses or other oral care products were not allowed in several of the trials. If you take prescription medication, check with a pharmacist or doctor before using it.

How strong is the scientific evidence for oraCMU?

NutraSmarts rates the evidence for oraCMU as Limited (2 out of 5). It is backed by 4 study summaries and 16 cited references summarized on this page. A higher rating reflects more, larger, and better-designed human studies.

References(16 citations)

Evidence ratings on NutraSmarts are based on the totality of human clinical research, with emphasis on randomized controlled trials, meta-analyses, and systematic reviews. The references below directly support claims made throughout this page.

  1. Kang MS, Lee DS, Lee SA, Kim MS, Nam SH. Effects of probiotic bacterium Weissella cibaria CMU on periodontal health and microbiota: a randomised, double-blind, placebo-controlled trial. BMC Oral Health. 2020;20(1):243. doi: 10.1186/s12903-020-01231-2.PubMedUsed to support: Double-blind trial in 92 adults aged 20 to 39 without periodontitis, after scaling: one oraCMU tablet nightly for 8 weeks improved bleeding on probing more than placebo at upper-jaw cheek-side and tongue-side sites, with no difference in probing depth, gingival index or plaque index; Fusobacterium nucleatum and Staphylococcus aureus were lower. The first author is an OraPharm employee.
  2. Lee DS, Lee SA, Kim M, Nam SH, Kang MS. Reduction of Halitosis by a Tablet Containing Weissella cibaria CMU: A Randomized, Double-Blind, Placebo-Controlled Study. J Med Food. 2020;23(6):649-657. doi: 10.1089/jmf.2019.4603.PubMedUsed to support: Breath report from the same 92-adult trial: the abstract reports drops in examiner odor scores and sulfur gases in the probiotic group at week 4 and lower self-rated breath scores at week 8, plus higher oral W. cibaria counts than placebo and no safety issues in blood tests or adverse events. An OraPharm employee is an author.
  3. Lee DS, Kim M, Nam SH, Kang MS, Lee SA. Effects of Oral Probiotics on Subjective Halitosis, Oral Health, and Psychosocial Health of College Students: A Randomized, Double-Blind, Placebo-Controlled Study. Int J Environ Res Public Health. 2021;18(3):1143. doi: 10.3390/ijerph18031143.PubMedUsed to support: Questionnaire report from the same trial (same ethics approval; 62 of 92 analyzed): after 8 weeks, 23.5% of the probiotic group vs 50% of the placebo group still felt they had bad breath, and oral health quality of life improved more; depression and self-esteem did not differ. One mild dry mouth on probiotic and one mild diarrhea on placebo were judged unrelated.
  4. Kang MS, Lee DS, Kim M, Lee SA, Nam SH. A Randomized, Double-Blind, Placebo-Controlled Trial to Assess the Acidogenic Potential of Dental Biofilms through a Tablet Containing Weissella cibaria CMU. Int J Environ Res Public Health. 2021;18(9):4674. doi: 10.3390/ijerph18094674.PubMedUsed to support: Plaque acid report from the same trial (68 analyzed): Cariview plaque acid scores fell in both groups with no significant difference between the probiotic and placebo groups. The first author is an OraPharm employee.
  5. Han HS, Yum H, Cho YD, Kim S. Improvement of halitosis by probiotic bacterium Weissella cibaria CMU: A randomized controlled trial. Front Microbiol. 2023;14:1108762. doi: 10.3389/fmicb.2023.1108762.PubMedUsed to support: Double-blind trial in 100 adults with bad breath: one chewed tablet with 100 million CFU nightly for 8 weeks lowered self-rated breath scores versus placebo at week 8 (the main outcome); total sulfur gases were lower at week 8 but already lower at baseline. Tablets were supplied by OraPharm; no author lists a maker affiliation.
  6. Lee SK, Lim KO, Yang KI, You SJ, Kang MS, Lee WP. Oral probiotic Weissella cibaria improves halitosis and reduces periodontal pathogens: a randomized, double-blind, placebo-controlled trial. BMC Oral Health. 2026;26(1):649. doi: 10.1186/s12903-026-08003-4.PubMedUsed to support: Double-blind trial in 80 adults with gingivitis or early periodontitis: two slow-dissolving 200 million CFU tablets daily for 8 weeks lowered total sulfur gases (main outcome), examiner odor scores and self-rated breath more than placebo; OHIP-14 did not differ between groups. An OraTicx employee is an author.
  7. Jeon HW, Yang KI, Yu SJ, Kang MS, Lee WP. Clinical Efficacy of the Probiotic Weissella cibaria CMU in Adults with Gingivitis: A Randomized, Double-Blind, Placebo-Controlled Clinical Trial. J Med Food. 2026;29(6):319-331. doi: 10.1177/1096620X261430298.PubMedUsed to support: Gum report from the same 80-adult trial: gingival index (primary) and bleeding on probing fell more than placebo, some inflammation-related proteins and three gum bacteria were lower, and no serious adverse events occurred. A corrigendum was published (PMID 41954142). An OraTicx employee is an author.
  8. Kim H, Oh S, Hong JS, Kang MS, Lee HJ, Park KU. Exploratory randomized trial of Weissella cibaria CMU and oral microbiome changes in peri implant mucositis. Sci Rep. 2026;16(1):12166. doi: 10.1038/s41598-026-42961-7.PubMedUsed to support: Exploratory trial in 40 analyzed patients with inflamed gums around dental implants: 4 weeks of oraCMU powder (200 million CFU per sachet, spread in the mouth twice daily) did not change the primary outcome, bleeding on probing, versus placebo; subgingival bacteria shifted and probing depth improved only in a moderate subgroup in a post hoc analysis. An OraTicx employee is an author.
  9. Dolan LC, Arceneaux BG, Do KH, Lee WK, Park GY, Kang MS, Choi KC. Toxicological and safety evaluations of Weissella cibaria strain CMU in animal toxicity and genotoxicity. Toxicol Res. 2022;38(3):293-310. doi: 10.1007/s43188-021-00119-9.PubMedUsed to support: Animal and lab safety work sponsored by OraPharm: no adverse effects in rats at the highest dose tested, 5000 mg/kg body weight a day (1.8 billion CFU/kg) for 13 weeks, and no genetic toxicity in bacterial, cell or mouse tests.
  10. Kang MS, Yeu JE, Hong SP. Safety Evaluation of Oral Care Probiotics Weissella cibaria CMU and CMS1 by Phenotypic |and Genotypic Analysis. Int J Mol Sci. 2019;20(11):2693. doi: 10.3390/ijms20112693.PubMedUsed to support: Lab study: CMU and CMS1 lacked transferable antibiotic resistance genes and virulence genes; CMU's kanamycin resistance was above the EFSA cut-off but intrinsic and did not transfer to another strain. Two of the three authors list the Oradentics research institute; the third is from the Korea Food Research Institute.
  11. Do KH, Park HE, Kang MS, Kim JT, Yeu JE, Lee WK. Effects of Weissella cibaria CMU on Halitosis and Calculus, Plaque, and Gingivitis Indices in Beagles. J Vet Dent. 2019;36(2):135-142. doi: 10.1177/0898756419872562.PubMedUsed to support: Animal study in beagles: the higher dose (2 billion CFU) lowered total sulfur gases from week 4 versus control, plaque index fell in both CMU groups, and several gum bacteria were lower. Co-authors list the Oradentics research institute.
  12. Do KH, Boo S, You R, Kim S, Kim S, Seo KW, Kang MS, Lee WK. Preventive effects of Weissella cibaria CMU on the progression of periodontitis in a rat model. J Oral Microbiol. 2025;17(1):2469895. doi: 10.1080/20002297.2025.2469895.PubMedUsed to support: Animal study in rats with induced gum inflammation: 14 days of CMU improved gingival and plaque indices and lowered TNF-alpha, IL-6, MMP-1 and MMP-9 in a dose-dependent way; bone loss by histology did not reach significance in the high-dose group. An OraTicx researcher is a co-author.
  13. Lim HS, Yeu JE, Hong SP, Kang MS. Characterization of Antibacterial Cell-Free Supernatant from Oral Care Probiotic Weissella cibaria, CMU. Molecules. 2018;23(8):1984. doi: 10.3390/molecules23081984.PubMedUsed to support: Lab study: most of the antibacterial effect of oraCMU culture fluid against gum bacteria depended on acid and hydrogen peroxide; 19 secreted proteins were identified, including N-acetylmuramidase, proposed as active against Porphyromonas gingivalis.
  14. Kang MS, Park GY, Lee AR. In Vitro Preventive Effect and Mechanism of Action of Weissella cibaria CMU against Streptococcus mutans Biofilm Formation and Periodontal Pathogens. Microorganisms. 2023;11(4):962. doi: 10.3390/microorganisms11040962.PubMedUsed to support: Lab study by OraTicx employees: CMU inhibited Streptococcus mutans biofilm and, in human gum fibroblasts exposed to gum bacteria, lowered IL-6, IL-1beta, IL-8 and TNF-alpha gene expression and MMP-1 and MMP-3; direct contact with the cells was needed.
  15. Oh JS. Lactic acid bacteria inhibiting halitosis US Patent 7,250,162 B2 (assignee: Industry Foundation of Chonnam National University). 2007;Filed April 22, 2005; granted July 31, 2007..SourceUsed to support: Not PubMed-indexed (US patent, read via Google Patents, accessed 2026). The claims name Weissella cibaria CMU with deposit number KCTC 10650BP, alongside strains CMS-1, CMS-2 and CMS-3; the assignee is the Industry Foundation of Chonnam National University.
  16. Stratum Nutrition. Stratum Nutrition and OraTicx sign exclusive distribution agreement for oral probiotics Stratum Nutrition news release. 2024;Posted August 19, 2024 (accessed 2026)..SourceUsed to support: Not PubMed-indexed (company news release). Describes OraTicx as a Korean oral probiotic company that makes oraCMU and names Stratum Nutrition as the sole distributor of OraTicx products across North America.