There were 6 x 8 = <<6*8=48>>48 bananas from the bunches with 8 bananas in a bunch.
There were 5 x 7 = <<5*7=35>>35 bananas from the bunches with 7 bananas in a bunch.
Therefore, Nathan had 48 + 35 = <<48+35=83>>83 bananas.
#### 83