Researchers a the University of Adelaide said their study shows the negative changes in oral bacteria resulting from dietary shifts as humans became farmers and later with the introduction of food manufacturing in the Industrial Revolution.
"This is the first record of how our evolution over the last 7,500 years has impacted the bacteria we carry with us, and the important health consequences," study leader Alan Cooper said.
"Oral bacteria in modern man are markedly less diverse than historic populations and this is thought to contribute to chronic oral and other disease in post-industrial lifestyles," he said.
"The composition of oral bacteria changed markedly with the introduction of farming, and again around 150 years ago," he said. "With the introduction of processed sugar and flour in the Industrial Revolution, we can see a dramatically decreased diversity in our oral bacteria, allowing domination by caries-causing [tooth decay] strains.
"The modern mouth basically exists in a permanent disease state," he said.