“Genetics may not explain most nutritional differences among people,” said Spector. “Most of this variation that affects our weight, risk of diabetes and heart problems is potentially modifiable for an individual.” The researchers also analyzed how a person's metabolism may influence food choices, such as if it drives them to prefer savory or sweet foods or vice versa. However, Spector said that it was still unknown "how food preferences relate to food responses, but we do have the data.” Spector’s study also found that microbiomes differ between identical twins, who shared only about 37% of their gut microbes with each other. By comparison, the study found that unrelated people share about 35% of the same gut microbiota. - abcnews.go.com