Lactobacillus paracasei (K71 / LP33) for Irritable Bowel Syndrome
Verdict: Published with Warning
Across 6 PubMed studies, the evidence for Lactobacillus paracasei (K71 / LP33) in Irritable Bowel Syndrome grades Tier C — weak evidence. Effective, but with safety or population caveats.
C 🟠 C Weak Evidence Published with Warning
Why this grade7-layer evidence engine
⚖️
Scoring transparency
All scores computed by a 7-layer evidence engine — fully auditableRaw score 0.43
D
C
B
A
S
← counter-evidence / ineffectiveeffective / strong evidence →
Final grade
C · Published with Warning
Confidence
76%
Broadly consistent
Evidence level
E2
Multiple high-quality MAs (≥2 independent, consistent)
▸View the full decision path (audit trail)
- compute_raw_score — 加權公式: L2×0.30 + L3×0.25 + L5×0.25 + L11×0.10 + L1×0.10 = 0.43
- tier_from_score — 依分數區間映射至 tier letter
- apply_hec_rules — 高品質 SR/MA 顯示 positive (1 篇 > 0 negative)
- tier_strict_requirement_check — Tier 條件達標，未降階
- detect_disputes — 偵測到 0 個 hard + 1 個 soft dispute
- decide_status — 依 tier + dispute 結果決定 status
PubMed studies (6)L2 · primary research & systematic reviews
Strain-Specific Systematic Review with Meta-Analysis of Probiotics Efficacy in the Treatment of Irritable Bowel Syndrome
— See PubMed for details
View on PubMed Probiotics for the management of irritable bowel syndrome: a systematic review and three-level meta-analysis
— See PubMed for details
View on PubMed Efficacy of Lactobacillus paracasei HA-196 and Bifidobacterium longum R0175 in Alleviating Symptoms of Irritable Bowel Syndrome (IBS): A Randomized, Placebo-Controlled Study
Finding: Overall IBS symptom-severity improvement with L. paracasei HA-196 was NOT significantly different from placebo; only subgroup/secondary signals emerged (complete spontaneous bowel movements rose in IBS-C and fell in IBS-D, p=0.013; emotional well-being improved vs baseline).
View on PubMed Effect of Lactobacillus paracasei CNCM I-1572 on symptoms, gut microbiota, short chain fatty acids, and immune activation in patients with irritable bowel syndrome: A pilot randomized clinical trial
Finding: L. paracasei CNCM I-1572 did NOT significantly improve the primary clinical endpoints (abdominal pain/discomfort or degree of relief); it only altered surrogate markers (reduced Ruminococcus, increased acetate/butyrate, lowered IL-15).
View on PubMed Efficacy of a Synbiotic Containing Lactobacillus paracasei DKGF1 and Opuntia humifusa in Elderly Patients with Irritable Bowel Syndrome: A Randomized, Double-Blind, Placebo-Controlled Trial
Finding: The L. paracasei DKGF1 + Opuntia humifusa synbiotic gave a significantly higher overall responder rate than placebo (51.5% vs 23.5%, p=0.017), with improved abdominal pain and psychological well-being; note this is a synbiotic, not paracasei monotherapy.
View on PubMed Efficacy and Safety of New Lactobacilli Probiotics for Unconstipated Irritable Bowel Syndrome: A Randomized, Double-Blind, Placebo-Controlled Trial
Finding: A 3-strain mix containing L. paracasei (with L. salivarius and L. plantarum, 5:4:1) significantly increased SGA responder rate vs placebo (80.8% vs 45.8%, p=0.009; VAS responders 69.2% vs 41.7%, p=0.048), but the paracasei effect cannot be isolated from the co-administered strains.
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
The bugs that seem to help the most are called Bifidobacterium and Lactobacillus. However, not all experts recommend probiotics for IBS because the scientific evidence is limited. source↗