Why change something that has worked well for millennia?
Sourdough bread is what communities would have eaten for thousands of years until industrialised food production was introduced at the start of the 20th century.
It is a slow-fermented bread made with a live culture (or 'starter') of lactic acid bacteria and wild yeast which acts as a leavening agent. As such, it doesn't require commercial yeast to rise.
From a health perspective, slower fermentation unlocks the nutrients from the grains and naturally-occurring acids help to break down gluten making it more digestible for some people.