Question

what are the most common bacteria in the guts of each group? (italians vs hadza)

Explanation:

This requires knowledge of gut - microbiome studies in different populations. Research on gut bacteria in Italians and Hadza would involve microbiological analysis to identify the dominant bacterial species in each group.

Answer:

This information would need to be obtained from specific scientific studies on the gut microbiomes of Italians and Hadza. Without access to such research data, a specific answer cannot be provided.