What is Bifidobacterium, and does it work?
It’s a family of gut bacteria, not one probiotic. A few types have helped IBS or slow bowels in trials. But each result belongs to one exact strain, shown by a code on the label.
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What is Bifidobacterium?
Bifidobacterium is a group of bacteria that lives in your gut. They were first found in the poo of breastfed babies in 1899, and they make up most of the gut bacteria in healthy breastfed babies.
In adults they settle at about 3 to 6% of gut bacteria. Over 65, numbers usually fall.
Makers add them to yoghurts and supplements as a probiotic, which the NHS calls live bacteria promoted as having health benefits.
Think of a label like a full name. Bifidobacterium is the surname and lactis or longum the first name.
The code, such as BB-12, is like an ID number for one exact strain.
| Part of the name | Example | What it tells you |
|---|---|---|
| Family (genus) | Bifidobacterium, often shortened to B. | The whole group. Too broad to judge. |
| Type (species) | B. animalis lactis, also written B. lactis | A narrower group. Still not enough. |
| Strain code | BB-12 or HN019 | One exact strain. Trials test this. |
Sources: NHS; Eskesen 2015; Ibarra 2018
That code matters. The NHS says a type that helps one problem may not help others, and other types may not work as well.
So check the pack for a strain code before you buy. Without a code, you can’t look up the trial behind it.
What do BB-12, HN019 and other strains do?
Three of these were tested in IBS (irritable bowel syndrome, a long-lasting tummy problem with pain, bloating and changes in your poo). The NHS explains it on its IBS symptoms page.
| Strain | Who was tested | What the trial found |
|---|---|---|
| B. lactis BB-12 | 1,248 adults with few poos and tummy discomfort | More frequent poos than on dummy pills. Comfort no different. |
| B. lactis HN019 | 100 adults with gut symptoms, then 228 with constipation | Food passed faster in trial one, not trial two. |
| B. infantis 35624 | 362 women with IBS | Less pain and bloating, at only one of three doses. |
| B. bifidum MIMBb75 | 122, then 443 people with IBS | More felt relief than on dummy pills. The second used killed bacteria. |
| B. longum NCC3001 | 44 adults with IBS and low mood or worry | Low mood scores fell. IBS symptoms did not change. |
| B. breve BBG-001 | 1,315 very premature babies in England | No fewer cases of a serious bowel illness in premature babies (NEC), blood infections or deaths than dummy drops. |
Sources: Eskesen 2015; Waller 2011; Ibarra 2018; Whorwell 2006; Guglielmetti 2011; Andresen 2020; Pinto-Sanchez 2017; Costeloe 2016
BB-12 is the most searched. In its big trial, people taking it went more often than those on dummy pills, at 1 or 10 billion CFU a day.
CFU is a count of live bacteria. Both doses worked about the same.
HN019 is the same type as BB-12, but a different strain. In one trial, the time food took to pass fell from 49 hours to 21 on the higher dose, with no change on dummy pills. In people with constipation, it made no difference overall.
With B. infantis 35624, only the middle dose helped. The authors said each product needs testing at its final dose.
Several of these trials were paid for or run by the makers. Treat each as one result, not proof. Pick a strain that was tested on the problem you want help with.
Lactobacillus or Bifidobacterium: which is better?
Neither has been shown to win.
UK gut doctors (the British Society of Gastroenterology) pooled 45 trials in 6,352 people with IBS. Probiotics as a group may ease IBS symptoms or pain. In the pooled trials, Lactobacillus, Bifidobacterium and mixes of probiotics each helped.
But they say it’s not possible to recommend one type or strain. The evidence is very low quality.
Most probiotic foods use one or both. So pick by strain code and the problem it was tested on, not by family.
For the wider picture, see do probiotics work and prebiotics vs probiotics.
Is Bifidobacterium infantis for babies?
It’s named for them. B. infantis is unusually good at digesting the sugars in breast milk. In lab tests it grows better on them than other gut bacteria.
Very premature babies are a hospital matter. A UK trial gave B. breve to 1,315 of them and found no evidence of benefit. The US regulator warns probiotics may present serious risks to premature babies in hospital.
If your baby was born early or has a health condition, ask their doctor before giving any probiotic.
How to try a Bifidobacterium probiotic
For most people, probiotics appear to be safe. They’re sold as food, so a pack may not hold the bacteria listed, or enough of them, alive.
Five steps for a fair trial
- Choose a strain code that was tested on your problem.
- Take the trial dose every day.
- Give it a month, as the NHS suggests for IBS.
- For IBS, stop by 12 weeks if you’re no better.
- Ask a doctor first if you have a health condition or weak immune system.
Jot down your symptoms each week, so you can tell if anything changed.
A probiotic doesn’t replace anything your doctor prescribed. Never stop or change a prescribed medicine without your prescriber.
Bloated or on antibiotics? See the best probiotic for bloating and probiotics with antibiotics.
When to speak to a GP
See a GP if you think you have IBS and have had symptoms for over 4 weeks. They can check for IBS and rule out other problems.
Ask for an urgent GP appointment or call 111 if:
- you’ve lost a lot of weight for no reason
- you’re bleeding from your bottom or have bloody diarrhoea
- you find a hard lump or swelling in your tummy
- you’re short of breath, can feel your heartbeat (palpitations) and your skin is paler than usual
These could be signs of something more serious. A probiotic won’t fix them, so don’t wait to see if one helps.
Want to know what a blood test can check? See IBS blood tests.