Precarious health of migrants arriving in Italy reflected in their gut microbiome

“The journey undertaken by migrants to reach Italy — characterised by trauma, dietary changes, and extreme living conditions — leaves a measurable imprint on their gut health. These alterations may increase vulnerability to infection and inflammation, further compromising a population already exposed to multiple health risks”, says Marco Candela, a Professor at the University of Bologna’s Department of Pharmacy and Biotechnology and the coordinator of the study on the gut microbiome of asylum seekers arriving in Italy.

Published in Scientific Reports , the study revealed a strong imbalance in the intestinal bacterial ecosystem, probably due to the extreme conditions faced during migration. Specifically, researchers observed a significant reduction in microbial diversity alongside an increase in opportunistic bacteria, both of which signal potential negative consequences for refugees' health.

“Forced migration is not only a geopolitical phenomenon; it is an event with a profound impact on human health. Monitoring the microbiome of asylum seekers allows us to better understand their health requirements and intervene more effectively”, Candela says.

According to the World Migration Report by the International Organization for Migration (IOM), the global number of migrants has more than tripled since 1970. It is estimated that since 2008, an average of 21.5 million people have been forced to migrate every year. In 2024, Italy received the highest number of sea arrivals in Europe, totalling 41,617 individuals.

While health data for those arriving on Italian shores remains scarce, researchers emphasise the critical need to monitor the physical impact of the migratory journey. Consequently, following a year of microbiological surveillance at the Borgo Mezzanone asylum seeker reception centre (in the province of Foggia, in southern Italy), the team analysed the gut microbiome of 79 newly arrived asylum seekers from African countries. The findings were compared against the microbiomes of rural and urban populations across various continents, as well as a group of Italian citizens.

The analysis reveals that the refugees’ microbiome exhibits a unique profile: it retains certain characteristics typical of the rural populations of origin while showing clear signs of stress, dysbiosis, and a loss of microbial taxa considered sensitive and beneficial.

"The microbiota of refugees is significantly less diverse than that of the rural African populations from which many presumably originate, showing an increase in opportunistic bacteria often associated with inflammation or psycho-physical stress," explains Giorgia Palladino, a research fellow at the University of Bologna’s Department of Pharmacy and Biotechnology and the study’s first author. "We observed the loss of several microorganisms typical of the microbiota of non-industrialised populations, which are known to support functions crucial to gut health.This represents an early sign of microbial imbalance that warrants clinical and public health attention."

The researchers emphasise the urgent need to consider the microbiome as a health indicator within refugee reception policies. They hope these findings will encourage greater focus on the health of refugees arriving in European countries.

"Understanding how the journey and transit conditions affect the microbiota can help us design targeted interventions," Palladino says. "These data could prove useful, for example, in nutritional support, infection prevention, and stress management."

The study was published in Scientific Reports  with the title “Gut microbiome structure in asylum seekers newly arrived in Italy from Africa”. The authors are Giorgia Palladino, Daniel Scicchitano, Silvia Turroni, Simone Rampelli and Marco Candela from the Microbiome Science and Biotechnology Unit , operating within the Department of Pharmacy and Biotechnology at the University of Bologna, together with Marianna Marangi from the University of Foggia (Department of Clinical and Experimental Medicine).