New Research Details Subtype Competition and Therapeutic Potential

The Korea Food Research Institute (KFRI) has reported new findings on how core members of the human gut microbiota regulate their growth.

The study focused on Akkermansia muciniphila, a gut bacterium considered a promising candidate for microbiome-based therapies. Common in healthy individuals, A. muciniphila plays a role in maintaining gut balance and influences immune function and insulin sensitivity.

A research team led by Dr. Young-Do Nam at KFRI, in collaboration with Professor Kwang-Soon Kim at POSTECH and the company EnteroBiome Co., Ltd., conducted a large-scale analysis of gut microbiota from Korean individuals. They found that A. muciniphila is not a single species but consists of four distinct subtypes (clades I–IV), with most individuals carrying only one subtype.

Based on these results, the researchers proposed that the different subtypes compete with each other. They tested this through genomic and physiological comparisons, in vitro co-culture experiments, and tests in germ-free mice.

The results showed that clade II (AmII), which has limited ability to use mucin, can eliminate clade I (AmI), a subtype known for its more efficient mucin use. This helps AmII establish itself in the gut.

Further analysis revealed that AmII releases extracellular vesicles carrying proteins that specifically target and break down AmI cells. These vesicles damage the cell walls of AmI, leading to their removal.

In addition, the vesicles from AmII also promote its colonization by triggering an AmII-specific IgA antibody response in the host.

This study highlights a distinct growth regulation strategy in which certain A. muciniphila subtypes use extracellular vesicles to suppress competitors. The findings suggest that these subtypes may have evolved this mechanism as an adaptive response to competition for limited nutrients.

By elucidating the competitive dynamics among A. muciniphila subtypes based on large-scale gut microbiota data from Koreans, our research could contribute to the development of precision dietary interventions aimed at selectively modulating specific A. muciniphila subtypes.

Dr. Young-Do Nam, Korea Food Research Institute