What are the differences of the two statistical models (fitFeature vs fitZig) in metagenomeSeq?

There are two statistical models according to which data has been fitted or reshaped in metagenomeSeq to perform differential analysis:

  • fitFeature model: It is based on a zero-inflated Log-Normal mixture model. This approach is recommended by the author. Note this model currently only supports two-group comparisons.
  • zero-inflated Gaussian fit (fitZig model): It is based on a zero-inflated Gaussian mixture model. It can be used when multiple groups are present for differential abundance testing.