Lactobacillus paracasei (K71 / LP33) for Allergic Rhinitis

Verdict: Disputed

Across 6 PubMed studies, the evidence for Lactobacillus paracasei (K71 / LP33) in Allergic Rhinitis grades Tier C — weak evidence. High-quality studies disagree — the evidence is genuinely mixed.

C 🟠 C Weak Evidence Disputed

🔬Why this grade7-layer evidence engine

⚖️

Scoring transparency

All scores computed by a 7-layer evidence engine — fully auditable
Raw score 0.56
D
C
B
A
S
← counter-evidence / ineffectiveeffective / strong evidence →
Final grade
C · Disputed
Confidence
67%
Broadly consistent
Evidence level
E2
Multiple high-quality MAs (≥2 independent, consistent)

How strongly each layer supports this effect

lower = less supportive
L5 Clinical bodiesAuthoritative stance
0.40
L1 ExamineGlobal benchmark
0.50
L11 AI re-checkIndependent read
0.50
L3 MechanismPlausibility
0.65
L2 PubMedPrimary literature
0.75
Against Mixed Supports
View the full decision path (audit trail)
  1. compute_raw_score — 加權公式: L2×0.30 + L3×0.25 + L5×0.25 + L11×0.10 + L1×0.10 = 0.558
  2. tier_from_score — 依分數區間映射至 tier letter
  3. apply_hec_rules — 高品質 SR/MA 顯示 positive (2 篇 > 0 negative)
  4. tier_strict_requirement_check — | B→C 因 scope.conflation_risk=true 且 L11 獨評較低 (B7-2 tier cap)
  5. detect_disputes — 偵測到 1 個 hard + 1 個 soft dispute
  6. decide_status — 依 tier + dispute 結果決定 status

📄PubMed studies (6)L2 · primary research & systematic reviews

Efficacy and safety of the probiotic Lactobacillus paracasei LP-33 in allergic rhinitis (GA2LEN Study)
PMID: 24569538 2014 RCT (double-blind) n = 425
Finding: RQLQ global score decreased significantly more in LP-33 group than placebo (P=0.0255); ocular symptoms significantly improved (P=0.0029); however nasal total symptom score showed NO significant difference (P=0.1288).
⚠️ Industry-funded Effect size: MD -0.286 (95% CI -0.536 to -0.035) on RQLQ
View on PubMed
Treatment of perennial allergic rhinitis with lactic acid bacteria (Wang et al., LP-33)
PMID: 15059192 2004 RCT (double-blind) n = 80
Finding: QoL frequency score improved significantly more with LP-33 vs placebo (-16.02 vs -7.27, p=0.037); bother score (-16.35 vs -6.20, p=0.022); no severe adverse effects.
Mixed funding Effect size: ~9-10 point MD on QoL scale (no SMD reported)
View on PubMed
Evaluation of L. paracasei (HF.A00232) in children with perennial allergic rhinitis: a 12-week RCT (Lin et al.)
PMID: 24269033 2014 RCT (double-blind) n = 60
Finding: LP group had significantly lower PRQLQ after levocetirizine withdrawal (p<0.01); improvements in sneezing (p=0.005), itchy nose (p=0.040), swollen eyes (p=0.038); BUT no significant difference in NTSS/TSS/TTSS/ETSS or cytokines.
⚠️ Industry-funded Effect size: Not reported (per-domain p-values only)
View on PubMed
RCT of L. paracasei K71 intake on salivary sIgA release
PMID: 28439488 2016 RCT (double-blind) n = 54
Finding: Salivary sIgA increase significantly higher in K71 vs placebo at wk 8 (105.5 vs 52.7 μg/min, p=0.047); K71 previously shown to alleviate atopic dermatitis but this trial did NOT measure AR symptoms.
🟠 Limited quality ⚠️ Industry-funded Effect size: MD 52.8 μg/min (sIgA, surrogate immune marker only)
View on PubMed
Effects of Probiotics on Allergic Rhinitis: A Systematic Review and Meta-Analysis of RCTs
PMID: 35099301 2022 統合分析 n = 1,591
Finding: Slight improvement on some clinical/immunological measures but strain-dependent; L. paracasei LP-33 nasal symptom SMD -1.61 (95% CI -4.67, 1.45) — NOT statistically significant.
Effect size: SMD -1.61 (95% CI -4.67 to 1.45) for LP-33 nasal symptoms
View on PubMed
Do probiotics have a role in the treatment of allergic rhinitis? A comprehensive systematic review and meta-analysis
PMID: 27442711 2016 統合分析
Finding: 17/22 trials showed clinical benefit; all 5 L. paracasei trials showed clinically significant improvement vs placebo; LP-33 showed homogeneity in nasal QoL outcomes; seasonal AR particularly responsive.
Effect size: Not pooled across strains (narrative subgroup)
View on PubMed

🏛️Regulatory & authoritative positionsL4/L5 · FDA / EMA / NIH ODS / Cochrane / Mayo …

L5a NIH Office of Dietary Supplements
Cautious
A review of 23 studies (1,919 participants) in which probiotics were tested for treating allergic rhinitis found some evidence that they may be helpful for improving symptoms and quality of life... because the studies tested different probiotics and measured different effects, no recommendations about the use of probiotics could be made. source↗
L5e Specialty Society (condition-mapped)
Cautious
PMID 100% verifiedevery citation checked via NCBI Entrez
🔬6 PubMed studiesindependently re-checked by multiple sub-agents
engine_version: v1.0 claim_id: CLM-COND-allergic-rhinitis-INT-lactobacillus-paracasei-001 繁體中文版 →