A microbe found in the lower part of the gut that is associated with good health has been comprehensively analyzed and found to have a focused diet breaking down sugars locked away in mucus.
The new study, published in Nature Microbiology today (Friday 31 January) is a complete systematic analysis of how the human colonic beneficial microbe, Akkermansia muciniphila (AM) feeds on types of sugar found in the mucus secreted in the digestive system. The study focused on 66 enzymes that the AM microbe uses to break down mucus that is an essential part of the mucus layer that lines the human gastrointestinal tract.
Using mucus taken from a pig model, the team led by Dr. Lucy Crouch from the University of Birmingham found that a combination of enzymes from AM were able to completely break down the mucin. This establishes the first comprehensive understanding of the molecular mechanisms behind how any microbe breaks down the O-linked sugars.
This is the first time that we have comprehensively seen how microbes break down the food source O-linked sugars in the gut. This is the first time that a set of enzymes has been used to completely break down the glycan part of mucin. These newly characterized enzymes may be used in characterizing the different glycans that humans produce, which can be indicative of disease.
These glycans, and others like them, are receptors for a variety of pathogens and their toxins, such as Shiga toxin. So, if we can modify the glycans, we may be able to change the severity of disease.
AM proteins and outer membrane extracts of AM have been shown exert positive effects on the host e.g. a positive effect on metabolism. Some of these proteins interact with host receptors to likely suppress an immune response. AM is relatively close the host as it wants the mucus we produce so we probably interact with it in many different ways.
We know that AM is a hugely important microbe, and levels of the microbe can be a good indicator of overall health. The bacteria are always beneficial for the gut, and lower levels of it are associated with inflammatory diseases and diabetes. AM is hugely sensitive to decreasing levels of fiber in the diet too.”
Dr. Lucy Crouch, Sir Henry Dale Fellow, University of Birmingham and corresponding author of the study
Source:
Journal reference:
Bakshani, C. R., et al. (2025). Carbohydrate-active enzymes from Akkermansia muciniphila break down mucin O-glycans to completion. Nature Microbiology. doi.org/10.1038/s41564-024-01911-7.
