Sore ThroatNCT04297878
The BLIS Study: a Feasibility Study Assessing Compliance, Acceptability and Colonisation With Different Dosing Regimens of the Probiotic Supplement Streptococcus Salivarius K12 (Bactoblis®) in Adults
A study testing probiotic supplement Streptococcus salivarius K12 (Bactoblis®) in people with Sore Throat and Tonsillitis, run by University of Southampton.
Trial summary
Short title The BLIS study Full title A feasibility study assessing compliance, acceptability and colonisation with different dosing regimens of the probiotic supplement Streptococcus salivarius K12 (Bactoblis®) in adults Population 50 human adults with or without a history of significant sore throat in the past 12… Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- Conditions the study is for
- Sore Throat, Tonsillitis, Pharyngitis
- What is being tested?
- probiotic supplement Streptococcus salivarius K12 (Bactoblis®)
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 50 participants
- Where
- No sites listed yet
- Study dates
- 5 Mar 2020to 1 Jan 2022
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Adults over 18 years of age
- Fully conversant in the English language
- Able and willing (in the investigator's opinion) to comply with all study requirements
- Willing to take SsK12 and return throat swabs according to the study protocol
- We primarily aim to recruit participants with a history of sore throat, however we will also recruit healthy individuals with no history of sore throat if we are struggling to meet our recruitment target of 50. We are defining a 'history' of sore throat as two or more episodes of significant (as judged by the participant) sore throat/pharyngo-tonsillitis episodes in the past 12 months. However, if we are struggling to recruit, a decision may be made by the chief investigator to alter this definition to one or more episodes in the last 12 months, after consultation with the study team.
Who cannot join
- Involvement in a study involving the receipt of an investigational medical product within 30 days prior to, or during, the study period.
- Active symptoms of sore throat or other infection at the time of recruitment
- Presence of a chronic disease/condition (such as those affecting the oropharynx) which, in the view of the investigator, might impact on colonisation, impede analysis of the study results, put the participant at increased risk, or impact on the ability of the participant to follow the study procedures
- Participant unable to give informed consent
- Any confirmed or suspected immunosuppressive or immunodeficient state, or use of immunosuppressant medication (including oral steroids) within the last 30 days
- History of allergic disease or reactions likely to be exacerbated by any of the study treatment
- Current smokers (including e-cigarettes/vaping)
- Any other clinically significant (as determined by the investigator) abnormality on clinical examination
Trial locations and contacts
No sites are listed yet.
Merlin Willcox contact
About this study
Short title The BLIS study
Full title A feasibility study assessing compliance, acceptability and colonisation with different dosing regimens of the probiotic supplement Streptococcus salivarius K12 (Bactoblis®) in adults
Read more
Population 50 human adults with or without a history of significant sore throat in the past 12 months. We primarily aim to recruit participants with a history of sore throat, however we will also recruit healthy individuals if we are struggling to meet our recruitment target.
Interventions
Two groups will receive two different dosing regimens of Ssk12 probiotic oral lozenges:
- Group A: two SsK12 lozenges at night on days 1, 7 and 14.
- Group B: one SsK12 daily at night for 14 days. Throat swabs will be taken at baseline, and days 2, 7, 14, 21, 35
Objectives
- To evaluate the prevalence of colonisation with SsK12 (as determined by real-time Polymerase Chain Reaction [PCR] and culture of participant-take whole-mouth swabs at pre-determined time points during the study)
- To evaluate the acceptability of the two dosing regimens (as measured by participant-completed questionnaires)
- To evaluate participants compliance with the two dosing regimens (as reported by participants during completion of the questionnaires)
Rationale SsK12 probiotic supplements are recognised as safe food ingredients, and there is preliminary evidence to support their use as prophylactic therapy to prevent episodes of pharyngo-tonsillitis. Existing clinical trials have all given SsK12 once daily over a period of months. It remains unclear whether a once-daily dosing regimen is needed in order to establish and maintain colonisation.
Study design This is a prospective study for which we will recruit healthy adult participants with and without a history of sore throat/ pharyngo-tonsillitis. We will evaluate [1] the acceptability and feasibility of two different dosing regimens of SsK12 supplements (taken as oral dissolvable lozenges), and [2] compare the prevalence of colonisation with SsK12 at various time points in order to determine how long colonisation is maintained following a loading dose. A baseline whole-mouth swab will be taken, and participants will be randomly assigned (in a 1:1 ratio) to one of two groups ('A' or 'B'). Group A will take two SsK12 lozenges at night on days 1, 7 and 14. Group B will take SsK12 at night for 14 days. Participants will be provided with instruction on how to perform a self-taken whole-mouth swab, and asked to take swabs on days 2, 7, 14, 21, and 35, and return these to the study team by post. They will also be asked to complete two short online questionnaires (on day 14 and day 35) about their compliance with the probiotic, as well as their views on the dosing regimen and other aspects of the study. Maintenance of colonisation will be assessed using analysis of the returned throat swabs. No follow-up will be undertaken after day 35.
Sample size Total = 50 (25 in group A, and 25 in group B)
Setting
- NIHR Clinical Research Facility, Southampton General Hospital
- Cowley Road Medical Practice, Oxford
- Conditions
- Sore Throat, Tonsillitis, Pharyngitis
- Being tested
- probiotic supplement Streptococcus salivarius K12 (Bactoblis®)
- Medical subject headings
- Pharyngitis, Tonsillitis
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
probiotic supplement Streptococcus salivarius K12 (Bactoblis®)Dietary supplement
Probiotic food supplement
| Study group | Role | What they receive |
|---|---|---|
| Group A | Experimental | Taking two SsK12 lozenges at night on days 1, 7 and 14. Receives: Dietary Supplement: probiotic supplement Streptococcus salivarius K12 (Bactoblis®) |
| Group B | Active comparator | One SsK12 daily at night for 14 days. Receives: Dietary Supplement: probiotic supplement Streptococcus salivarius K12 (Bactoblis®) |
What is being measured
The primary outcome is the main question the study is designed to answer.
Prevalence of colonisation with SsK12
To evaluate the prevalence of colonisation with SsK12 (as determined by real-time Polymerase Chain Reaction [PCR] and culture of participant-take whole-mouth swabs at pre-determined time points during the study)
Measured: During study involvement (days 1-35)
Acceptability of dosing regimens
To evaluate the acceptability of the two dosing regimens as measured by participant questionnaires completed on day 14 and day 35 (which include questions on a 1-5 Likert scale, as well as an opportunity to write open comments),
Measured: During study involvement (days 1-35)
Compliance with dosing regimens
To evaluate participants compliance with the two dosing regimens. This will be self-reported by participants as part of the questionnaires completed on day 14 and day 35.
Measured: During study involvement (days 1-35)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted6 Mar 2020
- Study start5 Mar 2020 (estimated)
- Primary completion1 Jan 2022 (estimated)
- Study completion1 Jan 2022 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Sore ThroatStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- Two parallel groups
- Masking
- None (open label)
- Enrolment
- 50 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Southampton
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04297878
- Sponsor's protocol ID
- 52107.P
- Status last verified
- Mar 2020
- First submitted
- 28 Feb 2020
- Last updated
- 6 Mar 2020
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Wilcox CR, Cleary DW, Augustine M, Anderson R, Francis N, Lown M, Moore M, Little P, Clarke SC, Willcox M. BLIS study: a feasibility randomised controlled trial assessing compliance, acceptability and colonisation with different dosing regimens of the probiotic supplement Streptococcus salivarius K12 (Bactoblis) in adults in England. BMJ Open. 2026 Sep 15;16(9):e120406. doi: 10.1136/bmjopen-2026-120406.
PubMed 42744363
Study at a glance
From the registry record, last updated by the sponsor on 6 Mar 2020. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The BLIS Study: a Feasibility Study Assessing Compliance, Acceptability and Colonisation With Different Dosing Regimens of the Probiotic Supplement Streptococcus Salivarius K12 (Bactoblis®) in Adults
- ClinicalTrials.gov ID
- NCT04297878
- Acronym / sponsor ID
- 52107.P
- Conditions
- Sore Throat, Tonsillitis, Pharyngitis
- Study type
- Interventional
- Recruitment status
- Unknown status
- Enrolment
- 50 participants (estimated)
- Lead sponsor
- University of SouthamptonUniversity, hospital or other
- Study start
- 5 Mar 2020 (estimated)
- Primary completion
- 1 Jan 2022 (estimated)
- Study completion
- 1 Jan 2022 (estimated)
- First posted
- 6 Mar 2020 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Short title The BLIS study
Full title A feasibility study assessing compliance, acceptability and colonisation with different dosing regimens of the probiotic supplement Streptococcus salivarius K12 (Bactoblis®) in adults
Population 50 human adults with or without a history of significant sore throat in the past 12 months. We primarily aim to recruit participants with a history of sore throat, however we will also recruit healthy individuals if we are struggling to meet our recruitment target.
Interventions
Two groups will receive two different dosing regimens of Ssk12 probiotic oral lozenges:
- Group A: two SsK12 lozenges at night on days 1, 7 and 14.
- Group B: one SsK12 daily at night for 14 days. Throat swabs will be taken at baseline, and days 2, 7, 14, 21, 35
Objectives
- To evaluate the prevalence of colonisation with SsK12 (as determined by real-time Polymerase Chain Reaction [PCR] and culture of participant-take whole-mouth swabs at pre-determined time points during the study)
- To evaluate the acceptability of the two dosing regimens (as measured by participant-completed questionnaires)
- To evaluate participants compliance with the two dosing regimens (as reported by participants during completion of the questionnaires)
Rationale SsK12 probiotic supplements are recognised as safe food ingredients, and there is preliminary evidence to support their use as prophylactic therapy to prevent episodes of pharyngo-tonsillitis. Existing clinical trials have all given SsK12 once daily over a period of months. It remains unclear whether a once-daily dosing regimen is needed in order to establish and maintain colonisation.
Study design This is a prospective study for which we will recruit healthy adult participants with and without a history of sore throat/ pharyngo-tonsillitis. We will evaluate [1] the acceptability and feasibility of two different dosing regimens of SsK12 supplements (taken as oral dissolvable lozenges), and [2] compare the prevalence of colonisation with SsK12 at various time points in order to determine how long colonisation is maintained following a loading dose. A baseline whole-mouth swab will be taken, and participants will be randomly assigned (in a 1:1 ratio) to one of two groups ('A' or 'B'). Group A will take two SsK12 lozenges at night on days 1, 7 and 14. Group B will take SsK12 at night for 14 days. Participants will be provided with instruction on how to perform a self-taken whole-mouth swab, and asked to take swabs on days 2, 7, 14, 21, and 35, and return these to the study team by post. They will also be asked to complete two short online questionnaires (on day 14 and day 35) about their compliance with the probiotic, as well as their views on the dosing regimen and other aspects of the study. Maintenance of colonisation will be assessed using analysis of the returned throat swabs. No follow-up will be undertaken after day 35.
Sample size Total = 50 (25 in group A, and 25 in group B)
Setting
- NIHR Clinical Research Facility, Southampton General Hospital
- Cowley Road Medical Practice, Oxford
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
- Model description
- Two parallel groups
| Arm | Type | Receives |
|---|---|---|
| Group A | Experimental | Dietary Supplement: probiotic supplement Streptococcus salivarius K12 (Bactoblis®)Taking two SsK12 lozenges at night on days 1, 7 and 14. |
| Group B | Active comparator | Dietary Supplement: probiotic supplement Streptococcus salivarius K12 (Bactoblis®)One SsK12 daily at night for 14 days. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (5 listed)
- Adults over 18 years of age
- Fully conversant in the English language
- Able and willing (in the investigator's opinion) to comply with all study requirements
- Willing to take SsK12 and return throat swabs according to the study protocol
- We primarily aim to recruit participants with a history of sore throat, however we will also recruit healthy individuals with no history of sore throat if we are struggling to meet our recruitment target of 50. We are defining a 'history' of sore throat as two or more episodes of significant (as judged by the participant) sore throat/pharyngo-tonsillitis episodes in the past 12 months. However, if we are struggling to recruit, a decision may be made by the chief investigator to alter this definition to one or more episodes in the last 12 months, after consultation with the study team.
Key exclusion criteria (8 listed)
- Involvement in a study involving the receipt of an investigational medical product within 30 days prior to, or during, the study period.
- Active symptoms of sore throat or other infection at the time of recruitment
- Presence of a chronic disease/condition (such as those affecting the oropharynx) which, in the view of the investigator, might impact on colonisation, impede analysis of the study results, put the participant at increased risk, or impact on the ability of the participant to follow the study procedures
- Participant unable to give informed consent
- Any confirmed or suspected immunosuppressive or immunodeficient state, or use of immunosuppressant medication (including oral steroids) within the last 30 days
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| probiotic supplement Streptococcus salivarius K12 (Bactoblis®)Probiotic food supplement | Dietary supplement | Group A, Group B |
Primary outcome
Prevalence of colonisation with SsK12
Time frame: During study involvement (days 1-35)
To evaluate the prevalence of colonisation with SsK12 (as determined by real-time Polymerase Chain Reaction [PCR] and culture of participant-take whole-mouth swabs at pre-determined time points during the study)
Acceptability of dosing regimens
Time frame: During study involvement (days 1-35)
To evaluate the acceptability of the two dosing regimens as measured by participant questionnaires completed on day 14 and day 35 (which include questions on a 1-5 Likert scale, as well as an opportunity to write open comments),
Compliance with dosing regimens
Time frame: During study involvement (days 1-35)
To evaluate participants compliance with the two dosing regimens. This will be self-reported by participants as part of the questionnaires completed on day 14 and day 35.
Results and safety
Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 6 Mar 2020.
- Derived from this study: PubMed 42744363Wilcox CR, Cleary DW, Augustine M, Anderson R, Francis N, Lown M, Moore M, Little P, Clarke SC, Willcox M. BLIS study: a feasibility randomised controlled trial assessing compliance, acceptability and colonisation with different dosing regimens of the probiotic supplement Streptococcus salivarius K12 (Bactoblis) in adults in England. BMJ Open. 2026 Sep 15;16(9):e120406. doi: 10.1136/bmjopen-2026-120406.
- Individual participant dataSharing planned: No
Related trials for Sore Throat
Not yet recruiting
Enhanced Telemedicine in Primary Care for Acute Respiratory Tract Infections Study
Acute Respiratory Tract Infection, Ear Infection
Not yet recruiting
The Effect of Compound Chamomile and Lidocaine Hydronchloride Gel as an Endotracheal Tube Lubricant on Postoperative Pharyngeal and Laryngeal Complications in Thoracic Surgery Patients
Postoperative Sore Throat
Active, not recruitingObservational study
Dexmedetomidine Nasal Spray and Postoperative Sore Throat After Bronchoscopy
Postoperative Sore Throat, Bronchoscopy
Not yet recruitingPhase 4
A Single Dose of Intravenous Penicillin as an Adjunct to Oral Penicillin in the Treatment of Acute Tonsillitis, Peritonsillar Phlegmon, and Peritonsillar Abscess
Acute Tonsillitis, Peritonsillar Abscess
Not yet recruitingObservational study
A Multicenter Evaluation of SalivIQ™ Strep A for Detecting Group A Streptococcus From Saliva and Throat Swabs in Patients With Acute Pharyngitis
Streptococcal Pharyngitis, Group A Streptococcal Infection
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Merlin Willcox contact
Questions about this trial
What is this clinical trial studying?
A study testing probiotic supplement Streptococcus salivarius K12 (Bactoblis®) in people with Sore Throat and Tonsillitis, run by University of Southampton.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 8 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: status not confirmed, as of the sponsor's last update on 6 Mar 2020. Status can change between updates, so confirm with the study contact before making plans.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
Results are not available in the source record.
How can a doctor refer a patient or contact the research team?
Contact Christopher Wilcox, MBBCh (07828219938, christopher.wilcox@soton.ac.uk), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Prevalence of colonisation with SsK12 (time frame: During study involvement (days 1-35)). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT04297878, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 6 Mar 2020; AzTrials last refreshed its copy on 27 Oct 2026.