How does DoseRank decide what ranks #1?

Each product gets a composite score blending clinical strength, evidence, dose fit, trust and value. The #1 on the DoseRank tab has the highest composite; the other tabs re-rank the same products by Value, Trust, or Popularity. Placement is never paid.

Is a higher dose always better?

No. Dose-fit rewards landing inside the range studied for the outcome — over-dosing (common with melatonin) or under-dosing both lower the score. The goal is the effective dose, not the biggest number.

What does the Value score mean?

The Value score compares a product's price per serving with clinically relevant products ranked for the same outcome. A score of 50 is the typical price; above 50 means better value than typical, while below 50 means the product costs more than typical. It is a 0–100 value signal, not a percentile.

Why is the cheapest product not #1?

Cost is only one input. The cheapest pick here is a citrate form with weaker absorption and a stock-risk flag, so it leads on Value-for-cost but trails on the composite that also weighs evidence, dose fit and availability.

Are these affiliate links?

Retailer links may be affiliate links and DoseRank may earn a commission. Rankings and placement are determined by the scoring model only — never by payment from a brand.

Is this medical advice?

No. DoseRank summarizes evidence to help you choose; it is not a substitute for a clinician, especially if you are pregnant, breastfeeding, on medication, or managing a health condition.

DOSERANKEVIDENCE-BASED SUPPLEMENTS

Reduce gastrointestinal infections

DOSERANKEVIDENCE-BASED SUPPLEMENTS

Best Supplements for Gastrointestinal infection incidence | DOSERANK

Top decision cards

Best products for gastrointestinal infection incidence

Ranking by · Composite outcome score

Best overall — the composite outcome score.

Top pick · DoseRank

Why this ranks #1 for gastrointestinal infection incidence

Swanson Vitamins, FemFlora, Probiotic For Women, 9.8 billion CFU, 60 Vegan Capsules

Swanson Vitamins$0.21 / serving4.7 · 2,698Available now

Also helps with

Oral health

Atopic dermatitis symptoms

Diarrhea

Why this ranks here

Evidence fitLimosilactobacillus reuteri has moderate human evidence for this outcome.
Dose fitLimosilactobacillus reuteri at 2400000000 CFU lands inside the studied 1000000000-10000000000 CFU window.
Price / serving$0.21 per serving — mid price tier for this outcome.
AvailabilityIn stock across major retailers; 99% availability confidence.
TrustStrong trust signals — consistently high marks from verified buyer ratings.

The numbers

2400000000 CFUIn rangeinside the studied 1000000000-10000000000 CFU window

2400000000 CFU

1000000000 CFU

Compare top 3 Product data Open at retailer

The rest of the ranking · DoseRank

Top 10 ranked products

Swanson Vitamins, L. Reuteri Plus, 30 Vegan EMBO Caps® AP

Swanson VitaminsClinical87Dose fit77Popularity91$0.59/ serving

Jarrow Formulas, Fem Dophilus®, 60 Veggie Capsules

Jarrow FormulasClinical86Dose fit71Popularity96$0.61/ serving

Life Extension, FLORASSIST® Probiotic Heart Health, 60 Vegetarian Capsules (74 mg per Capsule)

Life ExtensionClinical86Dose fit71Popularity76$0.36/ serving

Humanx, Lactobacillus Gasseri & Reuteri+, 30 Veggie Capsules

HumanxClinical88Dose fit90Popularity76$0.95/ serving

NOW Foods, Clinical Heart Health Probiotic, 60 Veg Capsules (117 mg per Capsule)

NOW FoodsClinical86Dose fit71Popularity50$0.29/ serving

Probulin, Total Care Immune Probiotic + Prebiotic & Postbiotic with Real Elderberry, 20 Billion CFU, 30 Capsules

ProbulinClinical86Dose fit69Popularity50$1.14/ serving

Bluebonnet Nutrition, S. Boulardii Probiotic, 60 Vegetable Capsules

Bluebonnet NutritionClinical88Dose fit67Popularity30$0.76/ serving

Bio-K+, Probiotic Supplement, Heart Health, 60 Capsule

Bio-K+Clinical87Dose fit77Popularity30$0.64/ serving

Probulin, Women's Health Probiotic, 20 Billion CFU, 60 Capsules

ProbulinClinical86Dose fit69Popularity30$1.00/ serving

Top decision cards

Best products for gastrointestinal infection incidence

Ranking by · Composite outcome score

Best overall — the composite outcome score.

Top pick · DoseRank

Why this ranks #1 for gastrointestinal infection incidence

Swanson Vitamins, FemFlora, Probiotic For Women, 9.8 billion CFU, 60 Vegan Capsules

Swanson Vitamins$0.21 / serving4.7 · 2,698Available now

Also helps with

Oral health

Atopic dermatitis symptoms

Diarrhea

Why this ranks here

Evidence fitLimosilactobacillus reuteri has moderate human evidence for this outcome.
Dose fitLimosilactobacillus reuteri at 2400000000 CFU lands inside the studied 1000000000-10000000000 CFU window.
Price / serving$0.21 per serving — mid price tier for this outcome.
AvailabilityIn stock across major retailers; 99% availability confidence.
TrustStrong trust signals — consistently high marks from verified buyer ratings.

The numbers

2400000000 CFUIn rangeinside the studied 1000000000-10000000000 CFU window

2400000000 CFU

1000000000 CFU

Compare top 3 Product data Open at retailer

The rest of the ranking · DoseRank

Top 10 ranked products

Swanson Vitamins, L. Reuteri Plus, 30 Vegan EMBO Caps® AP

Swanson VitaminsClinical87Dose fit77Popularity91$0.59/ serving

Jarrow Formulas, Fem Dophilus®, 60 Veggie Capsules

Jarrow FormulasClinical86Dose fit71Popularity96$0.61/ serving

Life Extension, FLORASSIST® Probiotic Heart Health, 60 Vegetarian Capsules (74 mg per Capsule)

Life ExtensionClinical86Dose fit71Popularity76$0.36/ serving

Humanx, Lactobacillus Gasseri & Reuteri+, 30 Veggie Capsules

HumanxClinical88Dose fit90Popularity76$0.95/ serving

NOW Foods, Clinical Heart Health Probiotic, 60 Veg Capsules (117 mg per Capsule)

NOW FoodsClinical86Dose fit71Popularity50$0.29/ serving

Probulin, Total Care Immune Probiotic + Prebiotic & Postbiotic with Real Elderberry, 20 Billion CFU, 30 Capsules

ProbulinClinical86Dose fit69Popularity50$1.14/ serving

Bluebonnet Nutrition, S. Boulardii Probiotic, 60 Vegetable Capsules

Bluebonnet NutritionClinical88Dose fit67Popularity30$0.76/ serving

Bio-K+, Probiotic Supplement, Heart Health, 60 Capsule

Bio-K+Clinical87Dose fit77Popularity30$0.64/ serving

Probulin, Women's Health Probiotic, 20 Billion CFU, 60 Capsules

ProbulinClinical86Dose fit69Popularity30$1.00/ serving

Reduce gastrointestinal infections

Reduce gastrointestinal infections

Which ingredient types matter for gastrointestinal infection incidenceOpen to see which ingredient types matter for gastrointestinal infection incidence

Probiotics & Microorganisms

Fibers & Prebiotics

Best products for gastrointestinal infection incidence

Swanson Vitamins, FemFlora, Probiotic For Women, 9.8 billion CFU, 60 Vegan Capsules

Swanson Vitamins, L. Reuteri Plus, 30 Vegan EMBO Caps® AP

Jarrow Formulas, Fem Dophilus®, 60 Veggie Capsules

Life Extension, FLORASSIST® Probiotic Heart Health, 60 Vegetarian Capsules (74 mg per Capsule)

Humanx, Lactobacillus Gasseri & Reuteri+, 30 Veggie Capsules

NOW Foods, Clinical Heart Health Probiotic, 60 Veg Capsules (117 mg per Capsule)

Probulin, Total Care Immune Probiotic + Prebiotic & Postbiotic with Real Elderberry, 20 Billion CFU, 30 Capsules

Bluebonnet Nutrition, S. Boulardii Probiotic, 60 Vegetable Capsules

Bio-K+, Probiotic Supplement, Heart Health, 60 Capsule

Probulin, Women's Health Probiotic, 20 Billion CFU, 60 Capsules

What every metric means

Compare the top 3, side by side

Not sure which is right for you?

Get a personal report

Frequently asked

Which ingredient types matter for gastrointestinal infection incidenceOpen to see which ingredient types matter for gastrointestinal infection incidence

Probiotics & Microorganisms

Fibers & Prebiotics

Compare the top 3, side by side

Best products for gastrointestinal infection incidence

Swanson Vitamins, FemFlora, Probiotic For Women, 9.8 billion CFU, 60 Vegan Capsules

Swanson Vitamins, L. Reuteri Plus, 30 Vegan EMBO Caps® AP

Jarrow Formulas, Fem Dophilus®, 60 Veggie Capsules

Life Extension, FLORASSIST® Probiotic Heart Health, 60 Vegetarian Capsules (74 mg per Capsule)

Humanx, Lactobacillus Gasseri & Reuteri+, 30 Veggie Capsules

NOW Foods, Clinical Heart Health Probiotic, 60 Veg Capsules (117 mg per Capsule)

Probulin, Total Care Immune Probiotic + Prebiotic & Postbiotic with Real Elderberry, 20 Billion CFU, 30 Capsules

Bluebonnet Nutrition, S. Boulardii Probiotic, 60 Vegetable Capsules

Bio-K+, Probiotic Supplement, Heart Health, 60 Capsule

Probulin, Women's Health Probiotic, 20 Billion CFU, 60 Capsules

Reduce gastrointestinal infections

Reduce gastrointestinal infections

Which ingredient types matter for gastrointestinal infection incidenceOpen to see which ingredient types matter for gastrointestinal infection incidence

Probiotics & Microorganisms

Fibers & Prebiotics

Best products for gastrointestinal infection incidence

Swanson Vitamins, FemFlora, Probiotic For Women, 9.8 billion CFU, 60 Vegan Capsules

Swanson Vitamins, L. Reuteri Plus, 30 Vegan EMBO Caps® AP

Jarrow Formulas, Fem Dophilus®, 60 Veggie Capsules

Life Extension, FLORASSIST® Probiotic Heart Health, 60 Vegetarian Capsules (74 mg per Capsule)

Humanx, Lactobacillus Gasseri & Reuteri+, 30 Veggie Capsules

NOW Foods, Clinical Heart Health Probiotic, 60 Veg Capsules (117 mg per Capsule)

Probulin, Total Care Immune Probiotic + Prebiotic & Postbiotic with Real Elderberry, 20 Billion CFU, 30 Capsules

Bluebonnet Nutrition, S. Boulardii Probiotic, 60 Vegetable Capsules

Bio-K+, Probiotic Supplement, Heart Health, 60 Capsule

Probulin, Women's Health Probiotic, 20 Billion CFU, 60 Capsules

What every metric means

Compare the top 3, side by side

Not sure which is right for you?

Get a personal report

Frequently asked

Related outcomes

Related outcomes

Which ingredient types matter for gastrointestinal infection incidenceOpen to see which ingredient types matter for gastrointestinal infection incidence

Probiotics & Microorganisms

Fibers & Prebiotics

Compare the top 3, side by side

Best products for gastrointestinal infection incidence

Swanson Vitamins, FemFlora, Probiotic For Women, 9.8 billion CFU, 60 Vegan Capsules

Swanson Vitamins, L. Reuteri Plus, 30 Vegan EMBO Caps® AP

Jarrow Formulas, Fem Dophilus®, 60 Veggie Capsules

Life Extension, FLORASSIST® Probiotic Heart Health, 60 Vegetarian Capsules (74 mg per Capsule)

Humanx, Lactobacillus Gasseri & Reuteri+, 30 Veggie Capsules

NOW Foods, Clinical Heart Health Probiotic, 60 Veg Capsules (117 mg per Capsule)

Probulin, Total Care Immune Probiotic + Prebiotic & Postbiotic with Real Elderberry, 20 Billion CFU, 30 Capsules

Bluebonnet Nutrition, S. Boulardii Probiotic, 60 Vegetable Capsules

Bio-K+, Probiotic Supplement, Heart Health, 60 Capsule

Probulin, Women's Health Probiotic, 20 Billion CFU, 60 Capsules