Development and validation of embedded multilayer attention graph convolution neural network models for predicting...

Identifying associations between gut microbes and diseases is crucial for uncovering disease mechanisms and advancing precision medicine. However, experimentally validated microbe-disease associations remain scarce due to time-consuming and costly validation. Existing computational methods face three measurable challenges: (1) severe class imbalance (positive associations constitute only 1.89-2.56% of all possible pairs); (2) difficulty in capturing nonlinear relationships inherent in microbial community interactions; and (3) limited capacity for propagating information across heterogeneous networks with sparse connectivity (graph density < 0.03).

To address these limitations, we propose MAGMDA, a graph convolutional neural network embedded with a multi-layer attention mechanism. MAGMDA integrates known microbe-disease associations, microbial functional similarity, and disease semantic similarity into a heterogeneous network. A graph convolutional encoder learns low-dimensional embeddings of microbes and diseases, while a multi-head additive attention mechanism (8 attention heads) is incorporated into each convolutional layer. Attention weights are computed via softmax normalization over layer-wise embeddings and shared across all nodes to preserve input feature contributions and mitigate information decay. A linear decoder reconstructs the association matrix, and the model is optimized using a weighted binary cross-entropy loss to enhance sensitivity to positive associations.

Evaluated on the HMDAD dataset and independently validated on the Disbiome dataset (4,351 associations between 218 diseases and 1,052 microbes), MAGMDA achieves average AUC improvements of 1.87% (HMDAD) and 1.44% (Disbiome) over the second-best method, with an average AUPR improvement of 1.83% (HMDAD). Case studies on asthma and type 2 diabetes-both closely linked to gut microbiota-show that the top 30 predicted microbes are strongly supported by published literature. Preliminary external validation using real-world clinical data (290 osteoarthritis patients vs. 290 healthy controls) and animal experiments (6 rabbits per group for osteoarthritis; 6 mice per group for diabetic cardiomyopathy) provides supporting evidence for the model's ability to identify gut microbes associated with osteoarthritis and diabetic cardiomyopathy, though further large-scale validation is needed.

MAGMDA offers a robust computational framework for prioritizing gut microbe-disease associations, with strong potential to guide hypothesis-driven research and reduce the burden of experimental validation in microbiome studies.