Best probiotic drops for babies

If you suspect formula intolerance contributing to fussiness, also read how to switch formula without an upset belly.

What probiotics actually do

Probiotics are live bacteria intended to improve the balance of gut flora. The reasoning: a healthy gut microbiome supports digestion, immune function, and possibly mood. Babies' gut microbiomes are still developing, especially in the first year, and certain "good" bacteria may help.

Probiotics are NOT a single product — they're a category. Different strains do different things. A probiotic marketed for adults to improve digestion is not the same as one researched for infant colic.

The one strain with real research

Lactobacillus reuteri DSM 17938 is the most-studied infant probiotic. Multiple randomized controlled trials have shown:

• Reduced crying time in breastfed infants with colic (about 50 to 60 minutes less crying per day in some studies).
• Possible benefit for regurgitation and constipation in some infants.
• No serious adverse events in trials.

It's sold as BioGaia Probiotic Drops in the US and most countries. The dose is 5 drops once daily.

The same strain is also studied for prevention of antibiotic-associated diarrhea, prevention of necrotizing enterocolitis in NICU babies (used under medical supervision), and possible benefits for atopic dermatitis prevention.

1. BioGaia Probiotic Drops — best researched

Single strain (Lactobacillus reuteri DSM 17938). 5 drops daily. Refrigerated for best potency. Comes in a 5 ml bottle that lasts about 25 days at 5 drops/day.

What we liked: most-studied infant probiotic. Recommended by many pediatricians for colic. Single strain, easy to evaluate.

What we didn't: pricey at $35 to $45 per bottle. Refrigeration required for full potency. Sunflower oil base might bother soy-allergic babies (though it's sunflower, not soy).

2. Gerber Soothe Baby Probiotic Drops — popular mid-range

Single strain (Lactobacillus reuteri DSM 17938) — same as BioGaia. Sold in the US baby aisle. Same dosing (5 drops/day).

What we liked: same active strain as BioGaia, often slightly cheaper. Easier to find in stores.

What we didn't: smaller bottle size means more frequent re-buys. Some users report different bottle valves than BioGaia.

3. Mommy's Bliss Infant Probiotic Drops

Single strain (Lactobacillus rhamnosus GG) — different strain from BioGaia. Has its own research base, primarily for diarrhea prevention and lactose intolerance support, less so for colic specifically.

What we liked: organic certification. Different strain may help if BioGaia hasn't worked.

What we didn't: the research evidence for the L. rhamnosus strain in infant colic is weaker than for L. reuteri.

4. Evivo Infant Probiotic — bifidobacterium for breastfed babies

Contains B. infantis EVC001 — a specific strain that breastfed babies' guts use to digest human milk oligosaccharides. Targets the modern decline of B. infantis in Western infant guts.

What we liked: addresses a documented gap in modern infant microbiomes. Strong research base from Stanford and UC Davis.

What we didn't: expensive ($60+ per box of 28 daily packets). Specifically for breastfed babies (not as well-studied in formula-fed).

5. Genexa Infant Probiotic Drops — additive-free option

Multi-strain (Lactobacillus rhamnosus + Bifidobacterium lactis). Allergen-free, vegan, certified organic.

What we liked: clean ingredient list. Good for babies with multiple sensitivities.

What we didn't: multi-strain mixes are harder to evaluate (different strains, different research). Less specific colic research than BioGaia.

Probiotics we don't recommend

• Multi-strain "kitchen sink" probiotics without specific strain identification. If the label doesn't list specific strains with letter codes (like "Lactobacillus reuteri DSM 17938"), you can't evaluate the research behind it.
• Probiotic gummies marketed for older kids given to infants. The dose and form aren't designed for babies.
• Heat-treated "stabilized" probiotics that don't require refrigeration. Many of these have lower live-bacteria counts than the refrigerated equivalents.

When probiotics might help

• Colic: The strongest evidence. A 3 to 4 week trial of BioGaia for fussy babies with crying lasting 3+ hours/day.
• After antibiotics: Probiotics during and 2 weeks after antibiotic courses may reduce antibiotic-associated diarrhea.
• Acid reflux: Some evidence for L. reuteri reducing regurgitation episodes.
• Constipation: Mixed evidence; some strains help some babies.
• Atopic dermatitis prevention: Limited evidence for prenatal and infant probiotic use reducing eczema risk.

When probiotics probably don't help

• Healthy babies with no symptoms. Daily probiotics for prevention aren't shown to do much.
• Spit-up that isn't reflux. Normal infant spit-up resolves on its own; probiotics don't speed it.
• General "gut health" without specific issues. The marketing pitch outpaces the science.

How to dose

1. Read the label. Most infant probiotics are 5 to 10 drops once daily.
2. Deliver to baby's lower lip or on a clean finger.
3. If breastfed, can apply to the nipple right before nursing.
4. If bottle-fed, can add to a small portion of milk (1/2 oz) at the start of a feed — don't mix into a full bottle in case baby doesn't finish it.
5. Some probiotics need refrigeration. Read the label carefully.
6. Continue for a minimum of 3 to 4 weeks to evaluate effect. Most colic-targeted studies showed benefit by week 3.

How to know if it's working

For colic:

• Track daily crying time before starting (3 to 5 days baseline).
• Continue tracking during probiotic use.
• By week 3 to 4, look for at least 30 to 60 minutes/day reduction in crying.
• If no change at 4 weeks, probiotics aren't working for your baby. Stop.

For other reasons (gas, fussiness, sleep), the placebo effect is real. Many parents feel certain probiotics worked even when randomized trials show no benefit beyond placebo. That's fine — placebo effects are real benefits — but be honest about the uncertainty.

Safety considerations

Probiotics are generally considered safe for healthy babies. Talk to your pediatrician before starting if your baby:

• Was born premature (especially under 34 weeks).
• Has any immune compromise.
• Has a central line, NG tube, or other indwelling medical device.
• Has any severe GI condition.
• Is on antibiotics or other medications.

There have been rare case reports of probiotic-associated infections in immunocompromised infants. For healthy term babies, probiotics have an excellent safety record.

The wider context: gut microbiome

Beyond probiotic drops, factors that shape an infant's microbiome:

• Mode of delivery. Vaginal birth exposes baby to maternal vaginal flora. C-section babies have different early microbiomes.
• Feeding. Breast milk provides prebiotics (HMOs) that feed B. infantis. Formula-fed babies have a different flora.
• Antibiotic exposure. Antibiotics in pregnancy, delivery, or infancy reshape the microbiome.
• Time. The microbiome largely stabilizes by age 3.

When to call your pediatrician

• You're considering probiotics for any specific symptom — get personalized advice.
• Your baby is premature, immune compromised, or has any chronic condition.
• You suspect colic and want to discuss next steps.
• Persistent reflux, vomiting, or feeding issues.
• Your baby developed unusual symptoms after starting a probiotic.