We all know about probiotics. They’re friendly bacteria that are delivered to the intestinal tract via supplementation or fermented foods, where they confer various health benefits such as digestive and immune support1—right? Well, only partially right. While probiotics certainly reside in the intestines, there are other areas of the body where they also reside. This includes the oral cavity (i.e. tongue, throat, etc.).2 Here, I will focus on one particular probiotic microorganism, Streptococcus salivarius K12 strain, with well-documented, beneficial effects in throat health, ear health and even for the treatment of halitosis.
Bacterial Activity in the Oral Cavity
The bacterium Streptococcus pyogenes is the cause of some throat infections, including pharyngitis or “strep throat.” In human research,3-5 subjects possessing naturally higher levels of certain strains of the oral bacterium Streptococcus salivarius, which provide bacteriocin-like inhibitory substances (BLIS), were shown to be significantly less likely to acquire S. pyogenes.
Throat Health: Supplementation With Streptococcus Salivarius K12 Strain (BLIS K12)
In a controlled, 90-day study,6 researchers tested the Streptococcus salivarius K12 strain (hereafter referred to as BLIS K12) for its potential effect in preventing streptococcal pharyngitis and/or tonsillitis in 40 adults with a diagnosis of recurrent oral streptococcal pharyngitis. Twenty of these subjects took BLIS K12 daily in a tablet formulated to slowly dissolve in the oral cavity, while the other 20 subjects served as untreated controls. In addition, a six-month follow-up was included (without supplementation) to evaluate the potential for any long-term protective role that BLIS K12 might offer. Results showed that those using the BLIS K12 had about an 80 percent reduction in their episodes of streptococcal pharyngeal infection compared to the prior year’s incidence. The 90-day treatment was also associated with an approximately 60 percent reduction in the incidence of reported pharyngitis in the six-month period following use of the product. The product was well tolerated, and there were no treatment-related side effects.
In addition to adults, children also benefit from BLIS K12 supplementation. In fact, five studies in children have shown benefits for throat health.
Eighty-two children, including 65 with and 17 without a recent diagnosis of recurrent oral streptococcal infection, were enrolled in a similar, controlled, 90-day study.7 Of those with recurrent infection, 45 were treated with BLIS K12 daily in a slowly dissolving tablet, and the remaining 20 served as an untreated control group. The 17 children without a recent infection were used as an additional control group. As with the other study, a six-month follow-up period (without supplementation) was included to evaluate the potential for any long-term protective role that BLIS K12 might offer. The result was that the 41 children using BLIS K12 showed about a 90 percent reduction in their episodes of streptococcal pharyngeal. In the six-month follow-up, the incidence of pharyngeal infections was reduced by about 65 percent. Again, the product was well tolerated with no side effects.
In a placebo-controlled study,8 24 children with a history of frequent sore throats from tonsillitis were recruited into the study and treated with one billion CFU of BLIS K12 daily, or a placebo.
Results showed that the children receiving BLIS K12 experienced substantially fewer sore throats (0.11 per month) than they did before entering the study (0.33 per month) and also in comparison to the smaller placebo group (0.19 per month).
Another controlled study9 was conducted with 61 children who had a diagnosis of recurrent oral streptococcal disorders. Thirty-one of them were treated daily for 90 days with a slowly dissolving BLIS K12 tablet. The remaining 30 children served as the untreated control group. Twenty children (10 per group) were also assessed for viral infection. Results showed that the 30 children who completed the trial with BLIS K12 experienced a significant 90 percent reduction in their episodes of streptococcal pharyngeal infection, as compared to the prior year’s episodes. No difference was observed in the control group. The BLIS K12 group also showed a significant 80 percent decrease in the incidence of oral viral infections. Again, there was no difference in the control group. In addition, children treated with BLIS K12 needed less antibiotic therapy, less medication for reducing fevers and missed fewer days of school because of related illness.
The next controlled study10 examined the effects of BLIS K12 vs. placebo in 130 children with recurrent, tonsillitis caused by bacteria known group A beta-hemolytic streptococci (GABHS). Each subject was monitored for the occurrence of GABHS infection for at least 12 months following their entry to the study. Seventy-six of these children then undertook a 90-day program requiring once-a-day dosing a slow-dissolving BLIS K12 lozenge. No probiotic supplement was given to the remaining 54 children who served as controls. Results showed that even nine months after the use of BLIS K12 had been stopped, the probability of new GABHS infections was significantly lower (P>0.001) when compared to the period before dosing commenced. When compared to the untreated children, those taking BLIS K12 appear to have had significantly fewer GABHS infections, both during the 90-day period of prophylaxis and during the following nine months (P<0.001).
A very recent published study11 focused on a further evaluation of the role of BLIS K12 in the control of pediatric streptococcal disease—and whether its use could also provide protection against various nonstreptococcal infections. A total of 48 children with a recent history of recurrent pharyngeal streptococcal disease received BLIS K12 daily for 90 days, while 76 children with a very low recent occurrence of oral streptococcal disease served as the control group. Results showed that those children receiving the BLIS KL12 experienced a 90 percent reduction of streptococcal pharyngeal disease compared to the prior year. They also experienced a statistically significant reduction in tracheitis (bacterial infection of the trachea), viral pharyngitis, rhinitis, flu, laryngitis, acute otitis media, enteritis and stomatitis (inflammation of the mucous membrane of the mouth, e.g. canker sores), compared with untreated children.
Ear Health: Supplementation With BLIS K12
Nineteen young children prone to ear infections (otitis media) received a three-day course of amoxicillin.12 They also received of BLIS K12 daily, applied to the surface of their tongues. The results showed that in two children, the use of BLIS K12 colonized the oral cavity. In other children, BLIS K12 colonization extended beyond the oral cavity to also include the nasopharynx (the space above the soft palate at the back of the nose that connects the nose to the mouth). These results suggest that BLIS K12 colonization may have benefits for those with ear infections—which was exactly what was shown in the next study.
In a different study13 of 82 children with recurrent oral streptococcal infection, the researchers also examined the effects of BLIS K12 supplementation on otitis media (middle ear infection). The results were that after 90 days, children using BLIS K12 had about a 40 percent reduction in acute otitis media). In the six-month follow-up during which there was no further supplementation, the incidence of ear infections was reduced by about 65 percent.
In another study,14 children who were prone to recurrent otitis media were supplemented with one billion CFU daily of BLIS K12, or placebo, to examine the effect on the rate of infection recurrence. The children receiving BLIS K12 had far fewer ear infections (0.22 per month) than they did prior to entering the study (0.50 per month) and also in comparison to the placebo group (0.55 occurrences per month). The results of this study indicate that the occurrence of otitis media has been reduced for children in the active treatment group.
Halitosis Treatment: Supplementation With BLIS K12
Halitosis, commonly referred to as bad breath, is a noticeably unpleasant odor on the exhaled breath. “Test tube” research15 has shown that BLIS K12 is effective against several bacteria involved in causing halitosis. This led researchers to speculate if supplementation with BLIS K12 would be beneficial against halitosis in people as well—and it turned out that it indeed did.
In a two-week placebo-controlled study,16 BLIS K12 or placebo was given to 23 subjects with halitosis, following treatment with an antimicrobial mouthwash. The subjects undertook a three-day regimen of mouth rinsing with the antimicrobial mouthwash, followed at intervals by the use of a lozenge containing either BLIS K12 or placebo. Assessment of the subjects’ volatile sulphur compound (i.e. rotten egg smell) levels one week after treatment showed that 85 percent of the BLIS K12-treated group and 30 percent of the placebo group (mouthwash only) had substantial reductions. Testing showed that BLIS K12 suppressed the growth of black-pigmented bacteria in saliva samples and also in various strains of bacteria implicated in halitosis. Other research17 in people with halitosis showed similar beneficial results with BLIS K12 supplementation.
A Note on Dosage Forms and Potencies
It is important to use the correct probiotic dosage form with BLIS K12. Specifically, this probiotic should be delivered as a lozenge or some other dosage form that will allow it to remain in the mouth for a sufficient period of time (e.g. a few minutes) so that colonization in the oral cavity can take place. Secondly, the dosage should provide at least one billion CFU BLIS K12.
Streptococcus salivarius K12 strain, or BLIS K12, is a well-studied probiotic that resides in the oral cavity, rather than in the intestinal tract. BLIS K12 has solid science behind it for helping to prevent streptococcal pharyngitis and/or tonsillitis, ear infections (otitis media) and to help treat halitosis. Furthermore, the research has shown that BLIS K12 has benefit for adults and children alike. VR
1 FAO/WHO. Health and Nutritional Properties of Probiotics in Food including Powder Milk with Live Lactic Acid Bacteria. Report of a Joint FAO/WHO Expert Consultation on Evaluation of Health and Nutritional. Properties of Probiotics in Food Including Powder Milk with Live Lactic Acid Bacteria; 2001. Retrieved http://www.who.int/foodsafety/publications/fs_management/probiotics/en/index.html.
2 Horz HP, Meinelt A, Houben B, Conrads G. Distribution and persistence of probiotic Streptococcus salivarius K12 in the human oral cavity as determined by real-time quantitative polymerase chain reaction. Oral Microbiol Immunol. 2007 Apr;22(2):126-30.
3 Dierksen KP, Tagg JR. The influence of indigenous bacteriocin-producing Streptococcus salivarius on the acquisition of Streptococcus pyogenes by primary school children in Dunedin, New Zealand. In Martin DR, Tagg JR (Eds.) Streptococci and Streptococcal Diseases: Entering the new Millennium. XIV Lancefield International Symposium on Streptococci and Streptococcal Diseases. C/- ESR, Porirua. November 2000: 81-85.
4 Tagg JR. Prevention of streptococcal pharyngitis by anti-Streptococcus pyogenes bacteriocin-like inhibitory substances (BLIS) produced by Streptococcus salivarius. Indian J Med Res. 2004 May;119 Suppl:13-6.
5 Horz HP, Meinelt A, Houben B, Conrads G. Distribution and persistence of probiotic Streptococcus salivarius K12 in the human oral cavity as determined by real-time quantitative polymerase chain reaction. Oral Microbiol Immunol. 2007 Apr;22(2):126-30.
6 Di Pierro F, Adami T, Rapacioli G, Giardini N, Streitberger C. Clinical evaluation of the oral probiotic Streptococcus salivarius K12 in the prevention of recurrent pharyngitis and/or tonsillitis caused by Streptococcus pyogenes in adults. Expert Opin Biol Ther. 2013 Mar;13(3):339-43.
7 Di Pierro F, Donato G, Fomia F, Adami T, Careddu D, Cassandro C, Albera R. Preliminary pediatric clinical evaluation of the oral probiotic Streptococcus salivarius K12 in preventing recurrent pharyngitis and/or tonsillitis caused by Streptococcus pyogenes and recurrent acute otitis media. Int J Gen Med. 2012;5:991-7.
8 Burton JP, Chilcott CN, Power DA, Dawes PJ, Tagg JR. Preliminary Study: Effect of Streptococcus salivarius K12 on Recurrent Tonsillitis. Unpublished, internal report. 4 pgs.
9 Di Pierro F, Colombo M, Zanvit A, Risso P, Rottoli AS. Use of Streptococcus salivarius K12 in the prevention of streptococcal and viral pharyngotonsillitis in children. Drug Healthc Patient Saf. 2014 Feb 13;6:15-20.
10 Gregori G, Righi O, Risso P, Boiardi G, Demuru G, Ferzetti A, Galli A, Ghisoni M, Lenzini S, Marenghi C, Mura C, Sacchetti R, Suzzani L. Reduction of group A beta-hemolytic streptococcus pharyngo-tonsillar infections associated with use of the oral probiotic Streptococcus salivarius K12: a retrospective observational study. Ther Clin Risk Manag. 2016 Jan 19;12:87-92.
11 Di Pierro F, Colombo M, Zanvit A, Rottoli AS. Positive clinical outcomes derived from using Streptococcus salivarius K12 to prevent streptococcal pharyngotonsillitis in children: a pilot investigation. Drug Healthc Patient Saf. 2016 Nov 21;8:77-81.
12 Power DA, Burton JP, Chilcott CN, Dawes PJ, Tagg JR. Preliminary investigations of the colonisation of upper respiratory tract tissues of infants using a paediatric formulation of the oral probiotic Streptococcus salivarius K12. Eur J Clin Microbiol Infect Dis. 2008 Dec;27(12):1261-3.
13 Di Pierro F, Donato G, Fomia F, Adami T, Careddu D, Cassandro C, Albera R. Preliminary pediatric clinical evaluation of the oral probiotic Streptococcus salivarius K12 in preventing recurrent pharyngitis and/or tonsillitis caused by Streptococcus pyogenes and recurrent acute otitis media. Int J Gen Med. 2012;5:991-7.
14 Burton JP, Chilcott CN, Power DA, Dawes PJ, Tagg JR. Preliminary Study: Effect of Streptococcus salivarius K12 on Otitis Media. Unpublished, internal report. 5 pgs.
15 Masdea L, Kulik EM, Hauser-Gerspach I, Ramseier AM, Filippi A, Waltimo T. Antimicrobial activity of Streptococcus salivarius K12 on bacteria involved in oral malodour. Arch Oral Biol. 2012 Aug;57(8):1041-7.
16 Burton JP, Chilcott CN, Moore CJ, Speiser G, Tagg JR. A preliminary study of the effect of probiotic Streptococcus salivarius K12 on oral malodour parameters. J Appl Microbiol. 2006 Apr;100(4):754-64.
17 Burton JP, Chilcott CN, Tagg JR. The rationale and potential for the reduction of oral malodour using Streptococcus salivarius probiotics. Oral Dis. 2005;11 Suppl 1:29-31.
Gene Bruno, MS, MHS, the dean of academics for Huntington College of Health Sciences, is a nutritionist, herbalist, writer and educator. For more than 30 years he has educated and trained natural product retailers and health care professionals, has researched and formulated natural products for dozens of dietary supplement companies, and has written articles on nutrition, herbal medicine, nutraceuticals and integrative health issues for trade, consumer magazines and peer-reviewed publications. He can be reached at firstname.lastname@example.org.