What different parameters can I use to see any effect it has on the model?

% Train the classifier

Nb = NaiveBayes.fit(Xtrain,Ytrain,'Distribution',dist);

Answer 1

[Sai Veeramachaneni]

You can try all the parameters of NaiveBayes.fit as specified here.

For your information - According to the R2018a Release Notes NaiveBayes.fit (fitNaiveBayes) is replaced with fitcnb