Swedish researchers have identified specific taxonomic and functional characteristics of the gut microbiota that correlate with the probability of developing type 2 diabetes. It was found that six different types of bacteria increase the risk of the disease, while representatives of the families Erysipelotrichaceae, Coprococcus catus, and certain bacteria of the class Clostridia help reduce this risk.
As data accumulates, the understanding of the role of the gut microbiome in the pathogenesis of type 2 diabetes grows. Although much evidence is based on comparative studies indicating a link between reduced microbial diversity and decreased butyrate production and the development of the disease, the causal relationship remains unclear. A group of scientists led by Gael Tubon from Chalmers University of Technology studied the characteristics of the microbiome in people who were not taking medication.
The researchers performed whole-genome sequencing of the microbiome in 4685 people over 70 years old. During five and a half years of observation, 383 of these participants were diagnosed with type 2 diabetes. The analysis did not reveal a significant dependence between alpha and beta diversity of the microbiota and the risk of the disease. However, a positive risk was identified associated with six species of bacteria: Desulfovibrio piger, Alistipes communis, Akkermansia muciniphila, Ruminococcus gnavus, Alistipes finegoldii, and a bacterium from the family Lachnospiraceae.
Three taxa were found to be inversely related to the risk of developing the disease: bacteria from the family Erysipelotrichaceae, Coprococcus catus, and an unclassified bacterium of the class Clostridia. Given the known influence of dietary fiber consumption on the proliferation of A. muciniphila, the scientists further investigated this factor. They found that low fiber intake amplified the bacteria's influence on diabetes risk. Patients with diabetes showed fewer A. muciniphila with higher fiber intake, although this correlation was insignificant. Nevertheless, a significant relationship was established between the amount of A. muciniphila, fiber intake, and C-reactive protein levels, which is an indicator of inflammation in the body (p = 0.019).
Regarding functional and metabolic changes associated with type 2 diabetes, the highest positive correlation with risk was shown by asparagine degradation activity. At the same time, mannose degradation and pentose phosphate pathway activity had an inverse correlation with risk. The scientists believe that the obtained data deepen the understanding of the role of the gut microbiome in the development of this disease. Reproducing these results will allow for improved risk assessment and the development of personalized approaches combining diet and microbiome.
