New York, Aug 4 : Using real-world data and predictive models, the researchers have identified key factors that determine the success of faecal microbiota transplantation. According to the researchers, human gastrointestinal microbiota, also known as gut flora or gut microbiota, are the microorganisms, that live in the digestive tracts of humans. "When a person takes an antibiotic, it can wipe out multiple bacterial species and throw this delicate balance off-kilter. Clostridioides difficile is a common pathogen that colonizes a disrupted gut microbiota.," said study authors from the Brigham and Women's Hospital in the US. Faecal microbiota transplantation (FMT), in which stool from a healthy donor is transplanted into the colon of a recipient, is a successful treatment for recurrent C. difficile infection (rCDI). According to the researchers, C. difficile infection or (rCDI) is a bacterium that can cause symptoms ranging from diarrhoea to life-threatening inflammation of the colon.C. difficile is transmitted through the faecal-oral route -- poor hygiene or the contamination of food or water supply -- and is found all over the world. For the study, published in the journal Nature Communications, the research team explored how the dynamics of bacterial species may influence the success of FMT in treating rCDI. The team presents an algorithm to design personalised probiotic cocktails for patients with unhealthy gut microbiomes due to rCDI. "Designing a probiotic cocktail is challenging. All of the species in the cocktail interact within a complicated network," said study researcher Yang-Yu Liu. "When we look at one species that directly inhibits the growth of C. difficile, we must also make sure that it does not indirectly promote growth of C. difficile through interactions with other species in the cocktail," Liu added. The researchers began by modelling a microbial community and simulating the FMT process of treating rCDI. Next, they estimated how effective FMT would be at restoring the recipient's healthy gut microbiota. The team then analyzed real-world data from a mouse model and from human patients to validate the modelling.The theoretical model helped the team predict what factors determine the efficacy of FMT. They learned that FMT efficacy decreases as the species diversity of the infected person's gut microbiome increases. The team also developed an optimization algorithm to design a personalized probiotic cocktail to help individuals with rCDI. The algorithm is based on the ecological theory that designs a cocktail with the minimum number of bacterial species, while keeping the complicated ecological network of the species in mind. "The personalised probiotic cocktails contain species that are effective inhibitors of C. difficile and can be administered to patients with rCDI in order to restore their gut microbiota," the authors wrote. /IANS