Laboratory of Parasitic therapy (Kateřina Jirků)
The gut is not merely a bacterial world. Alongside bacteria, it is also home to intestinal protists and helminths — organisms that parasitology has long viewed mainly as infectious agents. Today, however, it is becoming clear that their story is more complex: some may cause harm, others may persist silently in the gut, and some may be associated with microbiome stability and immune balance. In our laboratory, we study this overlooked layer of the gut ecosystem, with a particular focus on commensal and benign eukaryotes. We are interested in how they relate to the host, the bacterial microbiota, diet, environment, animal contact, and inflammatory bowel diseases. Our research connects population-level mapping with molecular and microbiome analyses and extends to experimental testing of the potential effects of selected organisms on intestinal inflammation. We aim to understand under which conditions intestinal eukaryotes are harmful, when they represent a subtle part of the microbiome, and when they may contribute to a more stable gut ecosystem.
Research projects
Intestinal helminths and the regulation of inflammation
Intestinal worms, or helminths, have long been viewed mainly as undesirable organisms. Their relationship with the host, however, is far more complex. Over millions of years of shared evolution, they have developed the ability to influence the immune system and dampen inflammatory responses that would threaten their own survival. This ability raises an important question: Could the loss of helminths from industrialized societies be linked to disturbed immune balance and the rise of chronic inflammatory diseases such as Crohn’s disease, multiple sclerosis, asthma, or allergies?
In our laboratory, we focus on the rat tapeworm (Hymenolepis diminuta), which usually causes no symptoms in humans but, according to our results, may under certain conditions alleviate intestinal inflammation. We do not study it as an isolated organism, but as part of the gut ecosystem, where its effects are shaped by the host, the microbiome, immune status, and diet.
The aim of this project is to understand how H. diminuta enters the interactions between diet, the microbiome, and the immune system, and under which conditions it may contribute to the regulation of inflammation. This research helps explain why the loss of some helminths from the modern environment may be associated with chronic inflammatory diseases, while also exploring whether their biological effects could inspire new therapeutic approaches.
Protists and Human Health: A New Perspective on an Old Coexistence
Not every intestinal protist detected in a sample indicates a problem. To properly interpret findings in patients with gastrointestinal symptoms, we first need to understand what these organisms commonly look like in healthy people and animals. Healthy populations show that some protists may be a natural part of the gut microbiome without being associated with disease.
In our laboratory, we therefore study their occurrence, genetic variability, and possible sharing between hosts. We focus especially on situations in which humans and animals live in close contact, such as human–dog relationships or interactions between humans and non-human primates. We are interested in how animal contact, rural or urban environments, and other lifestyle-related factors shape the occurrence of intestinal protists.
This project creates a reference map of intestinal protists outside the clinical context. It shows that their significance cannot be understood only from samples collected from
Blastocystis: A gut protist at the crossroad of heath and inflammation
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Blastocystis is one of the most frequently detected intestinal protists in humans and animals. It was previously associated mainly with gastrointestinal symptoms and inflammatory diseases, but today it is often found in healthy individuals and in microbiomes with higher bacterial diversity. This is why we ask what its presence in the gut actually means: Is it a risk factor, a subtle part of the microbiome, or a sign of a more stable gut ecosystem?
Detection alone, however, does not equal function. Population-level and microbiome data reveal important associations, but they cannot determine whether Blastocystis actively influences the gut ecosystem or merely reflects its state. Its role is likely shaped by the broader context of the microbiome, immunity, lifestyle, and diet.
In our laboratory, we therefore combine population-level data with an experimental rat model of intestinal inflammation. We investigate whether Blastocystis colonization affects disease progression, the microbiome, and host immune responses, and under which conditions it may have a beneficial effect.
