A long-term study of more than 7,000 adults in Finland has found that people with more antibiotic resistance genes in their gut microbiome faced a significantly higher risk of death over 17 years. Researchers also found that diet, gut bacteria and even income and gender were linked to the burden of resistance genes in the body.
The study, published in Nature Communications, used national health records and stool samples from participants in the FINRISK population study. People with a higher “resistance burden,” or more antibiotic resistance genes in their gut, had a 40% higher risk of death and more than double the risk of sepsis. The findings were strongest for respiratory-related deaths.
“Finnish population studies are internationally unique thanks to the national health registers, and for the first time we were able to investigate the association of antibiotic resistance with population health over nearly two decades,” said Katariina Pärnänen, Academy Research Fellow at the University of Turku and first author of the study. “The prevalence of antibiotic-resistant bacteria is constantly increasing, and large population studies help us to better understand the role of demographics and lifestyle in mitigating the problem."
While antibiotic use was the most important predictor of resistance burden, the researchers also found that certain dietary patterns played a role. Bacteria commonly associated with the Western diet, such as Escherichia coli and Bacteroides, were linked to higher resistance. These bacteria are more common in people who regularly consume processed meats, refined grains and added sugars. In contrast, Bifidobacteria and Prevotella, gut microbes associated with a fiber-rich diet, were linked to lower resistance burden. People who ate more berries, potatoes and rye bread also had lower resistance levels.
Food hygiene also mattered. Raw vegetables, salad and chicken, which can carry resistant bacteria, were linked to a higher resistance burden. So were social and lifestyle factors. Women, people living in cities, and those with higher incomes were more likely to carry higher levels of resistance genes.
“The results are interesting because these factors predicting a higher resistance burden are generally associated with better health,” Pärnänen said.
Although the study does not show causation, it suggests that resistance burden could serve as a long-term indicator of overall health status. The researchers emphasized the role of technology in helping uncover these patterns.
“Our research shows how machine learning and high-performance computing can help to solve public health challenges,” said Leo Lahti, professor of data science at the University of Turku. “The supercomputers managed by the Finnish IT Center for Science (CSC) are among the best in Europe and offer a significant international advantage for our research."
While reducing unnecessary antibiotic use remains the most effective way to lower resistance, researchers say individuals can still take meaningful steps.
“Prevention of infections, good hand hygiene, food hygiene and a balanced diet support gut health,” Pärnänen said. “By paying attention to these, everyone can help prevent the spread of antibiotic resistance.”
This research was supported by public funding agencies in Finland and the European Union.