Glycobiology connex with status of oral Rothia species

A healthy mouth is home to billions of bacteria that, together with the human host, form a delicately balanced oral ecosystem. When this balance is disrupted, harmful species can flourish and trigger tooth decay (caries) and gum disease (periodontitis) - two of the most common oral biofilm diseases worldwide. These infections are not only painful and expensive to treat but are also linked to wider health problems, including diabetes and cardiovascular disease. Yet some bacteria play a protective role, helping to stabilize the ecosystem and support oral health. Two such beneficial bacteria are Rothia dentocariosa and Rothia mucilaginosa. Although naturally present in many healthy mouths, these bacteria have been surprisingly understudied. Growing evidence suggests that Rothia species help reduce inflammation, inhibit disease-causing bacteria, and contribute to the production of nitric oxide - a molecule important for blood vessel and heart health. However, the molecular mechanisms that allow Rothia to thrive and interact beneficially with the microbial biofilm community and the human host remain largely unknown. Every cell in our body and many bacteria are covered with intricate patterns of sugar molecules called glycans. These sugars act like molecular identification tags, guiding how cells recognize, attach to, and communicate with one another. Early findings from the international project research team led by Christina Schäffer (BOKU University, Vienna, Austria) reveal that Rothia species possess a rich repertoire of glycans and that they are especially abundant in individuals whose cells naturally express a specific human glycan called the Lewis b antigen. This striking connection suggests the existence of a molecular dialogue between Rothia and its human host, written in the language of sugars, called glycocode. The project aims to decode this glycocode using state-of-the-art microbiological analytical, molecular, and bioinformatics technologies. The researchers will elucidate and map Rothias glycan structures, investigate how these bacteria recognize human glycans, explore whether they use the host sugars as nutrient sources, and determine how glycan-mediated interactions support a stable, health- promoting oral ecosystem. By uncovering these mechanisms, the team envisages to establish Rothia as a next-generation oral probiotic - a naturally occurring bacterium that could help prevent disease. Ultimately, this research may pave the way for innovative sugar-based strategies, including new probiotics and prebiotics, designed to support both oral and overall health without relying on antibiotics or aggressive treatments. By translating the sugar language of Rothia, this project moves oral microbiology beyond its traditional focus on pathogens and disease, toward a deeper understanding of health, resilience, and the remarkable molecular conversation that allow humans and their microbes to coexist in harmony.