Multi-omics approaches to investigate the role of Blastocystis in health and disease

Blastocystis is a protozoan anaerobe that inhabits the gastrointestinal (GI) tract of humans and other animals. It is extremely genetically diverse and has a complicated relationship with pathogenicity. In humans, most Blastocystis-positive cases are asymptomatic. However, some studies have found an association between Blastocystis and GI symptoms. So, what role does Blastocystis play in the gut? The gut microbiome is an extremely diverse community of over 100 trillion microorganisms, with bacteria hugely dominant. Understanding the relationship between Blastocystis and the bacterial component of the gut microbiome could help elucidate understanding of Blastocystis' role in causing GI symptoms. Does Blastocystis have an impact on the gut microbiome, which affects GI health? Using a range of molecular biology, biochemical, and epidemiological techniques, this study delves into the epidemiology of Blastocystis in South East England. It also investigates the impact of Blastocystis on the gut microbiome and gut metabolome, particularly in relation to irritable bowel syndrome (IBS) and ulcerative colitis (UC). The study further explores the effects of IBS treatment with antibiotics on the gut microbiome and metabolome and how these factors influence Blastocystis presence. Additionally, it examines Blastocystis' impact on the gut metabolome in diverse regions such as Thailand, Turkey, and Korea. Significant differences in metabolome composition were detected in Thailand, Turkey and Korea, and minimal differences were detected in South East England's cohort which microbiome and metabolome composition was studied. No differences in microbiome composition between Blastocystis subtypes or between Blastocystis and different risk factors were detected. The antibiotic course correlated with a decline in microbial diversity, Blastocystis presence, and a change in the gut metabolome. Both IBS and UC affected gut microbiome composition regardless of Blastocystis colonisation. This study marks a significant milestone as the first to directly investigate the relationship between Blastocystis and the gut metabolome. It also stands as the inaugural epidemiological study of Blastocystis in South East England. Moreover, it is the first comprehensive study to explore the impact of Blastocystis on the gut microbiome, metabolome, and IBS, as well as the effects of antibiotic treatment for IBS on the gut microbiome and its influence on Blastocystis presence.