Gaby
Do you love junk food? Blame it on the Black Death — the pandemic that wiped out millions in the Middle Ages.
The second plague pandemic, which killed about 60 percent of Europeans in the mid-14th century, changed the course of history. Researchers at Penn State and the University of Adelaide suggest its effects still ripple today, especially in the health of people who eat unhealthily.
The team believes our 21st-century taste for junk food may trace back to dietary and hygiene shifts from that era.
Analysis of calcified dental plaque from medieval skeletons showed that the bacteria dominating our mouths today are linked to low-fiber, high-carbohydrate diets and dairy consumption.
The researchers say these markers line up with what we now consider unhealthy eating. The Daily Mail reported that the Black Death may have helped those bacteria become dominant.
So changes in diet and hygiene during the plague affected our oral microbiome. That community of bacteria influences immunity, heart health and brain health, and may be linked to various diseases.
What Scientists Discovered
As Professor Laura Weyrich pointed out, “Modern microbiomes are associated with a wide range of chronic diseases, including obesity, cardiovascular diseases, and poor mental health.”
Her team collected material from the teeth of 235 individuals buried at 27 archaeological sites in England and Scotland, dating from 2200 B.C. to A.D. 1835. After processing the samples, the researchers identified 954 microbial species, which fell into two distinct bacterial communities.
One community was dominated by the genus Streptococcus, commonly found in the mouths of modern humans, while the other was dominated by the genus Methanobrevibacter, which is now considered extinct. The analysis showed that nearly 11 percent of the identified variations in microbiomes can be explained by historical changes, including the Black Death pandemic.
“We know that people who survived the second plague pandemic had greater wealth and could afford more calorie-dense foods,” Professor Weyrich said. It is quite possible that the pandemic caused changes in diet, which in turn affected the composition of the oral microbiome, she added.
This is the first time scientists have shown that events like medieval pandemics could influence the human microbiome.
The findings of the study were published in the journal Nature Microbiology.
