Everywhere on the inner and outer surfaces of our bodies, groups of microorganisms known as microbiomes exist. One of the most important microbiomes is the one found in our guts, where it contributes to digest our food.

Breastmilk delivers the right nutrients at the right time to the infant and its gut microbiome. A microbiome is created which is dominated by Lactobacillus and Bifidobacterium bacteria; also known from yoghurt products.

However, in some cases, infant formula is the only available mode of nutrition, creating a more heterogeneous microbiome with fewer bifidobacteria and higher numbers of harmful bacteria such as clostridia and staphylococci. These entail a risk of diseases.

Together with colleagues from Department of Food Science (UCPH FOOD), University of Copenhagen, and Arla Food Ingredients, researchers from Department of Food Science at Aarhus University have examined how prebiotic carbohydrates – a kind of non-digestible carbohydrate – may help solve the problem. 

Can carbohydrates help solve the problem?

PhD student Louise M. Arildsen Jakobsen, Department of Food Science and member of the science team Differentiated & Biofunctional Foods, explains why a specific type of prebiotic carbohydrates may be the solution:

- In our study we examined oligosaccharides, which are carbohydrates found in milk from humans and cows. Previous studies indicate that oligosaccharides may help stimulate the growth of bifidobacteria in the gut and support the immune system in infants.

The study focused on oligosaccharides from cows:

- Human milk oligosaccharides (HMO) are expensive and scarcely available, whereas bovine milk oligosaccharides (BMO) are not, and some of them are similar to human oligosaccharides. Therefore, we have used BMO as a starting point in our study. We have compared it to pure lactose and to synthetic galacto oligosaccharides, which are added to infant formula today – and we demonstrated some exciting results, says Louise M. Arildsen Jakobsen. 

New knowledge on synergy effects

The researchers examined the effect of oligosaccharides and lactose on eight different bacteria, which represent a simplified model of the infant microbiome. This was accomplished by separately testing bovine milk oligosaccharides and synthetic galacto oligosaccharides, as well as testing them together and also together with lactose.

- Our results demonstrate that lactose alone stimulate the growth of bifidobacteria, but also of the harmful clostridia bacteria. On the other hand, bovine milk oligosaccharides inhibit the growth of harmful bacteria, while they stimulate the growth of bifidobacteria as well as the so-called commensal bacteria of the Parabacteriodes species. Commensal bacteria means that they are either neutral or even beneficial. The effect of Parabacteroides has not been sufficiently clarified; however, recent data indicate that bifidobacteria and parabacteroides are able to coexist – and possibly with a beneficial effect on the metabolism of the bifidobacteria, says Louise M. Arildsen Jakobsen.

While focusing on possible synergy effects, the researchers discovered new and exciting results:

- During our study, we made a very interesting discovery – for the first time, we were able to demonstrate a synergy effect between lactose and bovine oligosaccharides (BMO). By combining these two, solely bifidobacteria growth is stimulated. Thus, our results show, that the composition of oligosaccharides may have a crucial effect on the infant’s microbiome, says Louise M. Arildsen Jakobsen, and she further concludes:

- We have achieved important new knowledge, which is valuable when it comes to the development of infant formula in the future. We can use the results from this model experiment as a guideline for the effects to be examined in future studies in order to establish more valid conclusions. 

Illustration: For the first time, researchers have demonstrated a synergy effect between lactose and bovine milk oligosaccharides (BMO) in relation to stimulating the growth of the Bifidobacteria species in the infant microbiome. Printed with permission from Jakobsen LM, Sundekilde UK, Andersen HJ, Nielsen DS, Bertram HC. Lactose and Bovine Milk Oligosaccharides Synergistically Stimulate B. longum subsp. longum Growth in a Simplified Model of the Infant Gut Microbiome. J Proteome Res. ACS Publications; 2019;18 (8):3086–98. Copyright 2019 American Chemical Society.

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