Some types of mosquitoes transmit malaria, which is caused by a parasite. About half of the people in the world are threatened by malaria, which affected an estimated 247 million people in 2021 alone; around 619,000 people died from the disease that year. There have been recent cases in the United States again as well. Malaria can cause illnesses that range from mild to severe. Symptoms can include confusion, breathing difficulties, fatigue, and seizures. Malaria prevention is important, particularly for communities that are commonly affected. There are treatments, but antimalarial resistance is a problem, and some drugs are becoming less effective in some cases. Now scientists have learned that gut bacteria are related to the severity of malaria cases. These findings could help researchers develop new ways to prevent the worst cases of the disease.
New findings have been reported in Nature Communications showing that the presence of several specific types of gut microbes can raise the likelihood that severe malaria will develop in a person. This work used data from a mouse model and humans.
Although there are new preventive measures like insecticides, better healthcare options, and vaccines, including one that can reduce malaria-related deaths, many gains have plateaued in recent years, said Nathan Schmidt, PhD, an associate professor of pediatrics at the Indiana University (IU) School of Medicine. "This plateau highlights the need for novel approaches to prevent malaria-related fatalities. Presently, there are no approaches that target gut microbiota. Therefore, we believe that our approach represents an exciting opportunity."
Previous work by Schmidt and colleagues showed that gut microbes can affect malaria severity. In this study, the investigators demonstrated that mice that carried Bacteroides gut microbes (and in particular: Bacteroides caccae, Bacteroides uniformis, and Bacteroides ovatus) had an increased risk of severe malaria. Pediatric patients with severe malaria were also found to carry high levels of these gut microbes.
This work was made possible in part by an international team and volunteer households who have a history of being affected by severe malaria. Some children carry the malaria parasite but do not have symptoms of illness, while others are more severely affected; this can help reveal the factors that are related to more serious cases, such as gut microbes.
"This opens the way to thinking about how we might alter those combinations in the gut to try to protect children from severe malaria," noted study co-author Chandy John, MD, MS, of IU School of Medicine.
"Beyond our efforts to assess the contribution of gut bacteria towards severe malaria in diverse African populations, we have initiated pre-clinical efforts to target gut bacteria that cause susceptibility to severe malaria," added Schmidt.
Sources: Indiana University, Nature Communications
