Probiotics for Babies: What We Know So Far

Probiotics for babies are said to treat diarrhea, ease allergies, and even help baby colic. But do they work? And are they really a good idea for babies?

We’ve enlisted the expertise of Registered Toddler Dietitian and Nutritionist (RDN) Kacie Barnes to share everything you need to know about infant probiotics.

In this article: 📝

What are probiotics for babies?

Probiotics are dietary supplements that are said to help improve the health of your gut. They can also be foods that contain live cultures

Probiotics for babies are the same — but the idea is they’re baby-friendly.

Let’s start from the top: A healthy adult gut contains bacteria, both ‘friendly’ and ‘not so friendly’. In fact, your gut is one great big collection of bacteria, AKA a ‘microbiome’, that all exists in a delicate balance.

When you become unwell — or when you take antibiotics — the sensitive balance of your microbiome can get upset, and symptoms like diarrhea, bloating, gas, and irritable bowels can result.

“Babies are also still working on developing this gut microflora,” explains Barnes, “so theirs just isn't as advanced as ours is!”

That’s where probiotics come in. These are ‘good’ bacteria you can take as a supplement — or eat in yogurt, cheese, and fermented foods — to help restore the balance in your microbiome.

By restoring that balance, you ease those uncomfortable symptoms. For adults, there is some evidence that they work. But what about babies? [1]

Are probiotics safe for baby?

The evidence suggests that probiotics are safe for babies and that they tolerate them well. That goes for healthy babies, pre-term babies, and babies with very low birth weight. [2]

But while probiotics may be perfectly safe for babies, we don’t know if they have the same positive effect that they do in adults. Though probiotics have been well tested in adults, that’s not the case with babies.

So, what’s the situation? Let’s go back to the gut again.

We know adult guts are a rich, diverse paradise for bacteria. But baby microbiomes are not that well-developed.

In fact, babies are born with sterile guts, where bacteria will develop in the future. As your baby eats and drinks, their microbiome flourishes. They get better and better at digesting food, and we know that their immune system develops, too. So, encouraging the growth of their microbiome with infant probiotics seems like a good idea, right? [3]

The trouble is that the little evidence we do have suggests something different. While probiotics are safe for babies, ‘probiotic exposure during infancy has limited effects on gut microbial composition’, as one study puts it. In other words, there might not really be any benefits. [4]

Should a baby be on a probiotic?

Many people claim that probiotics can help lots of different conditions in babies. But is this true?

Let’s take these claims one by one.

Do probiotics help fussy babies?

Here we may be in luck. Two studies have had success treating colic symptoms with probiotics.

One found that giving babies probiotics during the first three months can prevent colic. [5]

Another found that babies who take probiotics before feeding tend to cry less. [6]

But the jury is still out.

Another study found that babies treated with probiotics fussed more. [7]

Do probiotics help a baby poop?

Baby constipation can be a tough one — but there is some evidence that probiotics can help. One study found that babies taking probiotics poop more often. [8]

Do probiotics help gassy babies?

While doctors have suggested that an immature microbiome can maybe make babies gassy, there’s not much evidence to show that probiotics actually help. [9]

“Gas in infants can be caused by several other things, as well,” explains Barnes, “so it can be tricky to nail down the cause and find the right solution. Allergies and intolerances can also cause gas and fussiness.”

Does probiotics help with baby diarrhea?

There seems to be good evidence to support the idea that probiotics can help with the frequency, duration, and recovery time from diarrhea, particularly if they’re taken to counteract the side effects when your little one needs antibiotics. For this one, at least, thumbs up. [10]

Do probiotics help babies with allergies?

While it’s a common idea, there’s no evidence to support using probiotics for allergies — just yet, at least.

So, probiotics may be helpful for baby colic, baby diarrhea, and constipation. However, if you’re considering using them, it’s best to talk to your doctor first. They’ll be able to tell you everything you need to know.

Do breastfed babies need probiotics?

Short answer: usually not, but sometimes yes.

Breast milk is already pretty incredible. It naturally contains prebiotics (the food probiotics love) and beneficial bacteria that help build your baby’s gut microbiome from day one. For many breastfed babies, that’s enough to keep digestion ticking along nicely.

That said, some breastfed babies can benefit from probiotics — especially if they’ve:

• Been born via C-section
• Taken antibiotics (or you did while breastfeeding)
• Struggled with colic, reflux, gas, or constipation

According to a 2018 review, probiotics may be helpful in specific situations, but they’re not recommended as a routine supplement for all healthy infants. And ultimately, breast milk already plays a key role in supporting a baby’s gut health. [11]

Bottom line? If your breastfed baby is growing well and seems comfortable, probiotics probably aren’t necessary. If something feels off, it’s worth chatting with your pediatrician before adding anything new.

What time of day should a baby take probiotics?

There’s no magic hour on the clock, but consistency matters more than timing. Most pediatricians suggest giving probiotics once a day, ideally around the same time each day, and often with or right after a feed. Taking them alongside a feed can help the good bacteria survive stomach acid and make it to where they’re needed most.

For many parents, that naturally ends up being a morning or bedtime feed, simply because it’s easiest to remember and fits into the rhythm of the day. Probiotics don’t work like medication that needs perfect timing, so if the schedule shifts a little now and then, that’s okay. You’re already doing enough.

If your baby was prescribed a probiotic for a specific reason, like after a course of antibiotics, it’s best to follow your healthcare provider’s instructions closely.

Which probiotic is best for babies?

Not all probiotics are created equal. While we tend to group them, there are lots of different strains of probiotics that can have lots of different effects.

“The dose is also important as well,” says Barnes. “I would recommend looking for a dose that is similar to what is used in the studies that show positive results.”

As for which one is best? That depends on what you need it for:

• Lactobacillus: One of the most common probiotics out there, it’s credited with helping baby colic and diarrhea.
• Bifidobacterium: This is the dominant strain of bacteria in the gut throughout babyhood, and it seems to help their immune system develop. [12]
• Saccharomyces boulardii: Studies suggest this one might be the best bet for diarrhea. [13]

A big heads up: Probiotic supplements aren’t regulated by any government health board. So, you can never really be sure what you’re getting. Again, it’s probably best to talk to your doctor for advice before giving your baby probiotics.

How should babies take probiotics?

Finally, what’s the best way to give your little one what they need? Here are some important tips to keep in mind before giving probiotics to babies:

Babies don’t have to take the probiotics if you’re breastfeeding

What you eat can help your baby too. It’s known that lactobacillus and bifidobacterium can be passed to your baby through breastmilk, which means that your baby doesn’t need to take probiotics at all if you are.

Babies can have too many probiotics

Particularly if they’re immunocompromised or very unwell, probiotics might not always be completely safe. We just don’t know the full impact.

Babies can get probiotics from food too

While we don’t know everything about probiotic supplements, we do know that foods that contain probiotics are incredibly healthy for humans of any age. Once your baby’s ready for solids, fiber-rich foods, yogurt, and fermented foods are all great sources of probiotics.

When should babies take probiotics?

There aren’t any hard and fast rules on the best time for taking baby probiotics — mainly as we don’t yet know enough about how they work. But the studies we do have say taking probiotics before eating could be a good idea.

In terms of age, different products are marketed at different ages. But, as noted above, if you’re taking probiotics and still breastfeeding, you won’t need to give your baby any supplements.

What are the signs my baby needs probiotics?

Babies don’t come with instruction manuals (rude), so it’s normal to wonder whether gut issues are just “baby stuff” or something more.

Some signs probiotics may be helpful include:

• Ongoing gas, bloating, or fussiness, especially after feeds
• Colic symptoms (intense crying for long stretches with no clear cause)
• Constipation or irregular stools
• Diarrhea, particularly after antibiotics
• Frequent spit-up or reflux that seems uncomfortable

A 2021 review suggests that certain probiotic strains may support gut balance in babies with digestive disruption, but they’re not a cure-all. [14]

If your baby has poor weight gain, blood in stool, fever, or persistent vomiting, skip the probiotic aisle and call your pediatrician instead.

How quickly do probiotics help a baby?

This one’s a bit of a “depends,” because babies are tiny humans with very big opinions.

For many infants, parents start to notice changes within a few days when it comes to gas or stool patterns. Improvements in colic or reflux symptoms can take a little longer, often around one to two weeks, while more subtle shifts in overall gut balance may take up to a month.

That’s because probiotics work by gradually shaping the gut microbiome, not by flipping a switch overnight. If you haven’t seen any improvement after two to four weeks, it could mean the strain isn’t the right match for your baby, or that probiotics aren’t what they need right now.

What to remember before adding probiotics to your baby’s routine

Probiotics for babies may be useful for helping with diarrhea, colic, and constipation. But we don’t yet know for sure.

“We don't have enough evidence to promote prophylactic use,” says Barnes, “but there may be some evidence that they could be helpful tools in treating certain GI discomforts.”

If you’re breastfeeding and taking probiotics at the same time, your baby can get a probiotic boost through your milk. And as soon as your little one is ready for solid foods, they can get all the probiotics they need from them.