Preheat oven to 375 degrees (F) and line a 8.5 x 4.5†loaf pan with parchment paper; liberally grease. (Make sure you use a 8.5 x 4.5 loaf pan. If you don't, and use a 9 x 5, your loaf will spread out and bake out, instead of baking up like pictured.)In the bowl of an electric mixer, whisk together the sorghum flour, tapioca starch, millet flour, brown rice flour, flax seeds, baking powder, instant yeast, xanthan gum, and organic cane sugar.Mix in the sea salt.Add the honey and olive oil and turn the mixer to low. Slowly pour in the club soda.Mix on medium to medium-high until the batter is smooth and there are no lumps, about 45 seconds.Pour the batter into the prepared loaf pan and use a spatula to evenly spread the dough and smooth the top.Bake for 50-55 minutes, or until the top is golden brown and the inside of the loaf measures 200 degrees (F) with an instant read thermometer. Remove from pan and cool completely before enjoying.