Feeding pigs yeast from trees can promote healthy gut bacteria

New research performed in the centre for research-based innovation Foods of Norway at the Norwegian University of Life Sciences (NMBU), shows that feed based on novel ingredients from the Norwegian forest can have an effect on the microbiota in pigs’ guts. Through several trials, the research team found that the alternative feed increased lactic acid-producing bacteria in the small intestines of the pigs, which may protect young pigs from common infections.

Foods of Norway researcher Stanislav Iakhno has worked with the effect of yeast from woody biomass in the feed for pigs. He has recently submitted his PhD thesis on this subject and is certain that yeast grown on sugars from trees have implications for pigs’ health.

“In our trials, we evaluated the growth performance of the pigs fed yeast-based diets, which was similar to that of the pigs fed conventional diets. We also wanted to see what changes could be observed in the pigs’ gut”, Stanislav explains.

Encouraging bacteria

In several trials, the researchers found a consistency in how the novel feed affected the microbial composition in the gut, which was a finding Stanislav expected.

“Yeast cell walls are rich in fibres that only certain gut microbes can consume. So, it is not surprising that we could see an increase in the levels of lactobacilli, which have the enzymes to digest those fibres, in the piglets’ guts”, he explains.

The presence of lactobacilli in the gut is normally a positive thing. This indicates a potential for using novel ingredients as part of microbially directed feed, which implies changing something in a diet to get an increase or decrease of certain bacteria.

Based on his research, Stanislav suggests that enhancing the growth of beneficial gut microbes already present in the pig’s intestines may have a beneficial effect comparable to that of using in–feed probiotics.

“We see a possible boost in beneficial bacteria by using certain feed ingredients for livestock”, he says. 

 Next steps

The trials were based on a diet where yeast replaced up to 40 per cent of protein ingredients, which in this case was compared with a conventional soy meal-based diet.

“The main finding of this research is that feed based on yeast affects the microbiota of pigs. The exact underlying mechanisms of this must be the object of further experiments. As of now, we can see that the microbiota changes, and that this change does not affect the health of the lower gut”, Stanislav says.

Stanislav Iakhno admits that this project was meant to have a wide reach. The next logical step is to assess whether these changes in the pigs’ gut microbiota can be related to their health.

“This work has uncovered several different approaches to this area of research, meaning that our findings can be the basis for further hypotheses”, he says.


Stanislav Iakhno will defend his PhD thesis: «Porcine gut microbiota, short chain fatty acids, and gut health in response to a high yeast-inclusion diet» at NMBU Tuesday 14 December 2021.

Published 14. December 2021 - 13:33 - Updated 14. December 2021 - 13:33