A study of 575 people in Cameroon showed that parasitic infections are strongly linked to the structure of thegut microbiome. This suggests that modulating the microbiome can reduce the risk of diseases caused by intestinal parasites. Experts assume that almost a quarter of the world's population is infected with an intestinal parasite.
What can prevent parasitic infections?
Humans evolved with parasitic worms that theirgenetic diversityinfluenced by more than just climate, diet, bacteria or viruses. Today, tapeworm infections are relatively common, but in developed countries the overall rate of gastrointestinal parasites is relatively low. This is primarily because the work is relocated to more hygienic conditions and outside the country. However, in rural populations with more traditional lifestyles, intestinal parasites remain a part of daily life. The impact this has on the intestine and, more precisely, on the community of “good” bacteria living there is still unknown.
In a new study appearing in the journal Genome Biology, scientists at the University of Pennsylvania led a research team that examined the connection between parasites and the microbiome in people from Cameroon in central Africa. They found that parasitic infections are strongly linked to the composition of the gut microbiome. In some cases, the microbiome was able to predict the presence of intestinal parasites with 80% accuracy.
The role of good bacteria
The microbiome describes the community of microorganisms that live in and on our bodies and perform basic tasks. These would be, for example, protecting the body from pathogens, breaking down food and producing vitamins. The researchers behind the new study examined the connection between these helpful bacteria and parasitic infections in 575 people from Cameroon. The participants came from nine different villages that differed in terms of typical lifestyle. For example, Mbororo Fulani pastoralists herd cattle and eat a diet rich in meat and dairy products. In contrast, the people of Baka and Bagyeli live in the rainforest. They are hunter-gatherers, while Bantu-speaking agropastoralists grow crops and manage livestock.
Over a period of 6 months, the research team collected stool and blood samples from participants to study the bacteria in their gut. They also tested people for HIV and forMalaria and other parasites, which can infect the blood and gastrointestinal tract. The scientists also examined the gut health of a smaller number of people living in urban areas of the United States. They later treated everyone they found to have parasitic infections.
Results on parasitic infections
So the researchers found that almost 40% of the participants from Cameroon had an infection with more than one parasite. Subjects with a hunter-gatherer lifestyle most likely had multiple parasitic infections. The most common co-occurring parasites were soil-borne intestinal parasites. These are known as Ascaris lumbricoides, Necator americanus, Trichuris trichiura and Strongyloides stercoralis (ANTS). When the researchers combined parasite analysis with microbiome findings, they found that they could use a person's microbiome to predict with about 80% accuracy whether they were infected with ANTS parasites. They also found helpof the studyfound that the composition of intestinal bacteria can predict even more accurately whether a person comes from Cameroon or the USA and what their lifestyle is. For example, city dwellers, shepherds or hunters.
