Topic hub
Everything you need to know about Probiotics
Everything SupplementScore knows about probiotics — strain-specific evidence for IBS, antibiotic-associated diarrhea, infant colic, eczema, mood, and respiratory infection prevention.
Probiotic benefits are strain-specific. There is no single best product, and choosing by brand or "CFU count" without matching strain to indication wastes most of what you spend.
The short version
What the evidence shows: Tier 1 evidence for L. rhamnosus GG (AAD, pediatric diarrhea), S. boulardii (C. difficile, travel diarrhea), L. reuteri DSM 17938 (infant colic). Tier 2 for B. animalis (URTIs), B. infantis 35624 (IBS), L. gasseri (weight, women). Tier 3 / emerging for Akkermansia muciniphila.
Top three picks: L. rhamnosus GG (antibiotic-associated diarrhea); S. boulardii CNCM I-745 (travel / C. diff); L. reuteri DSM 17938 (infant colic).
Probiotics are one of the most-purchased and least-understood supplement categories. The single most important fact: benefits are strain-specific, not species-specific and certainly not generic. Lactobacillus rhamnosus GG has the best evidence for antibiotic-associated diarrhea and pediatric infectious diarrhea. Saccharomyces boulardii CNCM I-745 is the only yeast probiotic with strong trial data — used for travel diarrhea and C. difficile recurrence prevention. Bifidobacterium animalis subsp. lactis lowers respiratory infection frequency. Lactobacillus reuteri DSM 17938 is the most-studied probiotic in pediatrics, for infant colic. Lactobacillus gasseri has emerging weight and women's-health data. Akkermansia muciniphila is a next-generation strain with promising but early metabolic data. SupplementScore tracks 21 individual probiotic strains, 24 articles, and 7 conditions where strain selection actually matters.
Top supplements in the probiotics cluster
Each card shows the SupplementScore composite rating, evidence sub-scores, and a one-line summary. Click through for full dosing, timing, and safety detail.
Probiotic benefits are strain-specific — no single product works for everything. A 2025 meta-analysis found B. animalis reduced respiratory infections by 21%.…
The most studied probiotic strain in the world, with decades of clinical research. The 2020 Cochrane review (Collinson, previously Allen) concluded probiotics…
A unique probiotic yeast that antibiotics cannot kill, making it the only probiotic you can take during an antibiotic course without it being destroyed.…
A specific strain of the probiotic yeast S. boulardii with the strongest evidence for preventing antibiotic-associated diarrhoea and C. difficile recurrence.…
Helps reduce stress through the gut-brain connection. A 2024 review of 16 trials found the 1714 strain significantly reduces perceived stress and the morning…
A versatile probiotic strain with evidence across multiple health areas. The Protectis strain significantly reduces crying time in colicky infants. The ATCC…
One of the most studied probiotic strains in paediatrics. Cochrane reviews confirm L. reuteri DSM 17938 significantly reduces crying time in breastfed infants…
The most studied probiotic strain specifically for irritable bowel syndrome. Multiple trials show it significantly reduces IBS symptoms including bloating,…
A probiotic strain naturally abundant in breastfed infants, playing a key role in early immune development. Trials show it reduces eczema severity in children…
A naturally dominant species in healthy vaginal and gut microbiomes with the most consistent weight-management evidence of any probiotic strain. The Kadooka et…
A next-generation probiotic that lives in the mucus layer of your gut and strengthens the intestinal barrier. Low levels of Akkermansia are consistently linked…
One of the most well-studied probiotic strains available today. A 2024 review found it significantly reduces IBS symptoms including bloating, gas, and…
Articles in this hub
In-depth explainers, breakthrough research updates, and myth checks — grouped by editorial category.
Research updates
- The Gut-Brain Connection: How Probiotics Affect Your MoodThe gut-brain connection — how probiotics affect mood.
- Probiotics and Antibiotics: Timing MattersProbiotics and antibiotics — timing matters.
- The Gut-Immune Connection: Probiotics and Respiratory HealthProbiotics and respiratory infections — the gut-immune connection.
- Akkermansia muciniphila: the next-generation probiotic and what trials have actually shownAkkermansia muciniphila — the next-generation probiotic.
- Lactobacillus gasseri: The Probiotic Strain for Weight and Women's HealthL. gasseri — the strain for weight and women's health.
- Berberine for SIBO: the 2024-2025 evidence updateBerberine for SIBO — the 2024-2025 evidence update.
- Berberine and Gut Health: A Double-Edged SwordBerberine and gut health — a double-edged sword.
- Polyphenols and the Gut Microbiome: Prebiotic Effects Beyond FiberPolyphenols and the gut microbiome — prebiotic effects beyond fiber.
- Tributyrin: The Butyrate Prodrug and Its Gut Barrier EvidenceTributyrin and butyrate — the gut-barrier evidence.
Guides
- The Science of Gut Health: Beyond ProbioticsThe science of gut health beyond probiotics.
- Probiotic Strains for IBS: Which Species the Evidence Actually SupportsWhich strains actually have IBS evidence.
- Lactobacillus rhamnosus GG: The Most-Studied Probiotic StrainL. rhamnosus GG — the most-studied probiotic strain.
- Saccharomyces boulardii: The Yeast Probiotic Backed by Strong TrialsSaccharomyces boulardii — the yeast probiotic backed by strong trials.
- Zinc-carnosine for gastric ulcers and leaky gut: the Japanese trial recordZinc-carnosine for gastric ulcers and leaky gut.
Myths & misconceptions
Kids & pediatric
- Probiotics for Babies: What Pediatric Research ShowsProbiotics for babies — what pediatric research shows.
- Lactobacillus reuteri DSM 17938 for Infant Colic: What the RCTs ShowL. reuteri DSM 17938 for infant colic — what the RCTs show.
- L. reuteri DSM 17938 for Infant Colic: The Strongest Probiotic Evidence in PediatricsL. reuteri DSM 17938 — the strongest probiotic evidence in pediatrics.
- Probiotics for Infant Eczema: What 12 RCTs Show and Which Strain Actually MattersProbiotics for infant eczema — 12 RCTs and which strain matters.
- Probiotics for Infant Atopic Dermatitis: What the LGG and Perinatal Trials ShowProbiotics for infant atopic dermatitis — the LGG and perinatal evidence.
- Probiotic Strains for Antibiotic-Associated Diarrhea in Children: Which Species WorkAntibiotic-associated diarrhea in children — which strains work.
- Probiotics for pediatric functional abdominal pain: which strains have evidencePediatric functional abdominal pain — which strains have evidence.
- Probiotics for Kids After AntibioticsProbiotics for kids after antibiotics.
Conditions where probiotics is part of the protocol
Head-to-head comparisons
Common questions
What is the best probiotic?
Wrong question — there is no single best probiotic. The right question is "best for what?" For antibiotic-associated diarrhea: Lactobacillus rhamnosus GG or Saccharomyces boulardii. For travel diarrhea or C. difficile prevention: S. boulardii CNCM I-745. For IBS-D: L. rhamnosus GG or Bifidobacterium infantis 35624. For infant colic: L. reuteri DSM 17938. For respiratory infection prevention: B. animalis subsp. lactis. Buying a "broad-spectrum" 50-billion CFU product without matching strain to indication wastes most of what you spend.
Do probiotics actually survive stomach acid?
Most do not, in meaningful numbers — but it does not matter as much as marketing suggests. The mechanism for many strains is transient: they pass through the gut, interact with the immune system and existing microbes, and trigger downstream effects without colonising. Enteric-coated capsules and acid-resistant strains (like S. boulardii, which is a yeast) survive better, but for most indications the trial-tested product is the right answer regardless of survival claims.
Should I take probiotics with antibiotics?
Yes, but timing matters. Take probiotics 2 hours apart from the antibiotic dose so the antibiotic does not kill the probiotic. Continue for 1–2 weeks after finishing the antibiotic. The 2018 Cochrane review found L. rhamnosus GG and S. boulardii each cut antibiotic-associated diarrhea risk by roughly half in adults and children.
Can I get probiotics from food instead?
Fermented foods (yogurt, kefir, sauerkraut, kimchi) provide live bacteria but not the specific clinically-tested strains. For general gut health, fermented foods + dietary fiber + a varied plant intake outperform supplements for most healthy adults. For specific indications (IBS, AAD, infant colic, eczema prevention), a strain-matched supplement is the better tool.
Are probiotics safe?
Very safe in healthy people. The main risks are in severely immunocompromised patients, hospitalised patients with central venous catheters, and very premature infants — where rare cases of probiotic bacteremia or fungemia have been reported. Healthy outpatients can use trial-tested probiotics indefinitely with no known harm.
Evidence sources
- PMID 29257353 — Goldenberg JZ et al. 2017 — Probiotics for AAD in children, Cochrane Review.
- PMID 25927096 — Szajewska H et al. 2014 — L. rhamnosus GG for diarrhea, meta-analysis.
- PMID 27914762 — Goldenberg JZ et al. 2017 — Probiotics for C. difficile, Cochrane.
- PMID 29445213 — Sung V et al. 2018 — L. reuteri DSM 17938 for infant colic IPD meta-analysis.
- PMID 30873402 — Hao Q et al. 2015 — Probiotics for upper respiratory tract infections, Cochrane.
- PMID 30580726 — Ford AC et al. 2018 — Probiotics for IBS, AGA evidence review.
- PMID 30733721 — Depommier C et al. 2019 — Akkermansia muciniphila first-in-human trial.
- PMID 22529959 — Kalliomäki M et al. 2003 — L. rhamnosus GG for atopic eczema prevention.
- PMID 27158839 — Ouwehand AC et al. 2018 — Probiotic strain identification and CFU labeling adequacy.