Research

Research Introduction1: Elucidating the Molecular Mechanisms by Which Dietary Lipids Influence Host–Microbiota Symbiosis

Dietary lipids not only serve as a major energy source but also contribute to dietary diversity and palatability. However, excessive lipid intake can disrupt the symbiotic relationship between the host and gut microbiota,thereby contributing to the development of various metabolic disorders. In our research unit, we aim to elucidate how dietary lipids affect both the host’s regulatory mechanisms of gut microbiota and the structural characteristics of bacterial cells. Through these analyses, we seek to generate novel insights into preventing the disruption of host–microbiota symbiosis induced by excessive lipid consumption.

Research Introduction2: Elucidating the Role of Gut Microbiota in Human Diseases

Recent studies have revealed that alterations in the gut microbiota(dysbiosis) are associated with a wide range of human diseases. Our research unit aims to identify specific gut microbial profiles that contribute to the exacerbation of conditions such as graft-versus-host disease (GVHD) following hematopoietic stem cell transplantation,periodontitis, cancer, and non-alcoholic steatohepatitis (NASH). Using model animals, we are investigating the underlying mechanisms by which these microbial changes aggravate disease progression.Based on the findings obtained, we ultimately aim to propose novel strategies to prevent the onset and progression of these diseases by targeting the gut microbiota.

Research Introduction3: Elucidation of the pathogenicity of the periodontal pathogen Porphyromonas gingivalis

Oral bacteria not only cause dental caries and periodontal disease, but can also be involved in the onset and progression of systemic diseases such as diabetes and cardiovascular disease. One proposed mechanisms is the translocation of oral bacteria to the intestinal tract, where they disrupt the intestinal flora and negatively impact systemic health. Porphyromonas gingivalis is a representative periodontal disease bacterium, and its major virulence factor is gingipain, which has strong proteolytic activity. Gingipain and several other proteins are secreted extracellularly via the type 9 secretion system. We have identified a group of genes (operon) in the P. gingivalis genome that is essential for the proper function of gingipain. Our research aims to contribute to the development of a method to control this bacterium by clarifying the role of each gene in this operon and the effect of gingipain on the host.