Bifidobacterium breve. Image credit:  Advanced Microscopy team.

Bifidobacterium are a key group of ‘y’-shaped bacteria that make up a healthy gut microbiome.

There are many different strains, or types, of Bifidobacterium, including Bifidobacterium longum subspecies infantis (B. infantis), which is well known for its role in breaking down breastmilk sugars.

Bifidobacterium are one of the first and most common gut bacteria to grow in a newborn’s gut, shaping our microbiome early on in life and influencing our gut health in the longer term.

Foods like some yoghurts and supplements often contain Bifidobacterium as a beneficial bacterium. When taken in the right quantities, this friendly microbe can deliver a range of health benefits.

Digesting ‘undigestible’ sugars in breastmilk

Bifidobacterium is beneficial for our health because it breaks down complex carbohydrates from our diet, helping with digestion.

In particular, some Bifidobacterium like B. infantis digest human milk oligosaccharides well. Human milk oligosaccharides are complex sugars found in human breastmilk which a baby needs for development but pass undigested into the baby’s gut.

This is where Bifidobacterium excels: it crunches on the complex milk sugars in breastmilk, breaking them down into short-chain fatty acids so that babies can benefit from the full nutrition of breastmilk.

Short-chain fatty acids are compounds that provide a range of health benefits like strengthening gut barrier function, reducing inflammation and protecting our gut from disease-causing microbes. They also act as prebiotics, feeding the other good microbes in our gut.

Its sugar crunching role helps Bifidobacterium colonise the infant gut quickly after childbirth, where it starts impacting health outcomes early on in life. This becomes apparent when we study the gut microbiome in preterm babies.

Protecting preterm babies through probiotics

Premature babies are at high risk of developing serious gut conditions like necrotising enterocolitis because they lack helpful gut microbiome residents like Bifidobacterium. This can be made worse by antibiotic use which further depletes the infant microbiome.

The Baby-Associated MicroBiota of the Intestine (BAMBI) study led by Norfolk and Norwich University Hospital and Quadram Institute researchers – including Professor Lindsay Hall – investigated how Bifidobacterium supplements for preterm babies could give them a better start at life.

They found that disease risk was lower in preterm babies that were given Bifidobacterium to boost microbiome diversity and milk digestion compared to babies without supplementation.

The BAMBI study marked an important point in research on the mechanisms responsible for the beneficial impact of Bifidobacterium supplementation on preterm babies. In 2022, the World Health Organisation used these findings in their recommendations for premature infants.

Where do we get Bifidobacterium from

We’re learning more about Bifidobacterium and its role in pregnancy, early life and ageing here at the Quadram Institute.

The Pregnancy and Early Life (PEARL) study enrolled pregnant mothers and monitored their microbiome throughout pregnancy, as well as the infant’s microbiome after birth.

Our scientists wanted to understand how antibiotics, baby delivery and diet affect how the infant microbiome is shaped in early life. They collected samples across multiple years and locations in Norfolk, and are in the process of analysing the data.

As part of the PEARL study, we’ve been investigating how our gut microbiome residents change from infancy into old age.

More recently, the PEARL-Age study is enrolling family members to see how gut microbes, including Bifidobacterium along with many other gut microbes, are shared between family members across three generations.

Reprogramming the immune system for health

The beneficial compounds produced by Bifidobacterium fermentation can help control and reprogramme our immune system to our benefit.

Research shows that infants with healthy levels of Bifidobacterium in their gut almost always show improved results when it comes to vaccination.

We aren’t sure exactly why, but we do know that Bifidobacterium helps with immune cell development, like B cells, which trigger the production of beneficial antibodies.

This suggests that Bifidobacterium might raise vaccine efficacy in children. The future of research on the role of the microbiome in vaccination immune response is promising.

We’ve also studied how using Bifidobacterium’s ability to influence the immune system could help treat cancer. Cancer is caused by our immune systems glitching. Our previous research points to specific sugars produced by Bifidobacterium interacting with gut immune cells, redirecting them to tumours to shrink them.

So far, this has been shown in mice, but there’s a unique opportunity to explore whether these microbial compounds could be used to produce anti-cancer therapies in humans.

Diversity of Bifidobacterium across the animal kingdom

Although it’s great news for us that Bifidobacterium give humans a health boost, they don’t exclusively like us.

A new study from Quadram Institute and University of Birmingham scientists shows that zoo animals – including rodents, pigs and birds – also host Bifidobacterium living in their guts.

These Bifidobacterium from animals are new, previously undiscovered species that have adapted to the different animals’ diets and physiology.

Studying how Bifidobacterium has adapted to non-human animal hosts opens the door to developing new prebiotics and probiotics that can continue to benefit our health in the future.