Streptococcus salivarius K12 and sore throat
What 2 graded rows on streptococcus salivarius k12 agree on for sore throat, and where they differ. Counted side by side, never averaged.
Consensus finder Rows from the Streptococcus salivarius K12 page, reviewed Oct 21, 2026 How it decides
What the rows agree on
Each block and row is one graded row from the Streptococcus salivarius K12 page, with its PubMed record.
Your question
Streptococcus salivarius K12 and sore throat
2 rows · 3,160 peopleSplit. 1 row found no difference and 1 had mixed results.
- CGrade C× 1
- ∅No effect× 1
- Rows
- 2
- Trials
- 5
- People
- 3,160
- Pooled reviews may count some twice
What the rows share
From the rowsThe best-graded row, grade C, is a systematic review of 1,846 people (2019) and reported mixed results. 1 row is graded No effect, our grade for adequately powered trials that found no effect.
The rows run from 1,314 to 1,846 people, published from 2018 to 2019: 1 pooled review and 1 single study.
The rows
1 no difference · 1 mixed- ∅No effectStrep-positive sore throats in schoolchildren · No difference
RCT · n 1,314 · 2018 · Children aged 5 to 14 at high risk of rheumatic fever (New Zealand)
2.5 billion CFU per lozenge · One school year
7.8% of swabs from the K12 group and 8.8% from the placebo group grew group A streptococcus, a nonsignificant 11.2% relative reduction.
Row on the Streptococcus salivarius K12 page · PubMed 29189607 (opens PubMed)
- CGrade CStrep throat and tonsillitis · Mixed
Systematic review, 4 studies · n 1,846 · 2019 · Children and adults in 4 trials
Daily K12 (doses varied by trial) · 3 months to four school terms
All 4 trials were rated poor quality. An unblinded trial in 222 young children reported fewer strep infections (16.2% vs 48.6%), but a placebo-controlled trial in 1,314 schoolchildren found no difference (7.8% vs 8.8%). In adults given K12 with penicillin there was no benefit. K12 was well tolerated.
Row on the Streptococcus salivarius K12 page · PubMed 30616011 (opens PubMed)