Biology subjects

Kodaira, Y.

Publications and source records attributed to Kodaira, Y..

3 recordsLinked to original sources

bioRxiv2026

Acquisition of Stickland-metabolizing bacteria during infancy prevents Clostridium botulinum infection

Infant botulism is caused by intestinal colonization with Clostridium botulinum, whereas healthy adults are resistant. Although the gut microbiota has long been implicated in protection against C. botulinum, its bacterial basis has remained unknown. Here, we show that specific amino acid-metabolizing bacteria confer resistance to C. botulinum colonization through nutrient competition. Longitudinally collected human infant microbiotas exhibited a transition from susceptibility to resistance after transplantation into germ-free mice. 5-Aminovalerate marked the resistant microbiota, implicating Stickland metabolism. Resistant microbiotas were enriched in Stickland-metabolizing Clostridia, including Clostridioides difficile. Metabolomics revealed overlapping amino acid utilization, and C. difficile suppressed C. botulinum expansion through amino acid competition. These findings demonstrate that acquisition of Stickland-metabolizing Clostridia during infancy prevents C. botulinum infection through competition for shared amino-acid-dependent nutritional niches.

microbiology↗

bioRxiv2025

The HDAC2-selective inhibitor KTT-1 attenuates autoimmune arthritis by inhibiting osteoclast differentiation in mice

Histone deacetylases (HDACs) are crucial epigenetic regulators of gene expression through the reversible acetylation of lysine residues, and their inhibition is known to exert anti-arthritic effects. Given the critical role of osteoclasts in bone destruction in rheumatoid arthritis (RA) pathogenesis, targeting HDAC2--whose expression is upregulated during osteoclast differentiation--represents a promising therapeutic strategy. Although the development of highly specific HDAC2 inhibitors has recently attracted considerable attention, no such inhibitor has yet been successfully developed. In the current study, we found that the kinetic-selective HDAC2 inhibitor KTT-1 effectively suppressed arthritis symptoms in the collagen-induced arthritis (CIA) mouse model without causing severe side effects. Furthermore, KTT-1 inhibited osteoclast differentiation at an early stage by downregulating c-Fos expression, suggesting that the KTT-1-mediated anti-arthritis effect was achieved by inhibiting osteoclast differentiation. These findings highlight KTT-1 as a promising therapeutic candidate for the development of targeted synthetic disease-modifying antirheumatic drugs (tsDMARDs).

immunology↗

bioRxiv2025

Dietary soy shapes murine microbiota to consolidate the mucosal IgA response through T follicular helper cells

The commensal microbiota plays a crucial role in shaping mucosal immunity, particularly in the induction of T follicular helper (Tfh) cells and IgA production. Here, we demonstrate that dietary soy elicits a robust Tfh cell and IgA response in Peyers patches of weaning mice. Soy feeding promotes the expansion of two principal commensal bacterial species, Limosilactobacillus reuteri and Muribaculum intestinale. Mechanistically, L. reuteri provides cognate antigens for Tfh cell activation, while M. intestinale functions as an adjuvant by promoting IL-1{beta} production from myeloid cells. The resulting IgA exhibits polyreactivity and enhances protection against Salmonella infection. These findings highlight the specific interplay among dietary components, intestinal microbiota, and mucosal immunity, thereby establishing a diet-microbe-immune axis that shapes host defense in early life. This axis represents a promising therapeutic target for developing novel strategies to enhance resistance to enteric pathogens. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=170 HEIGHT=200 SRC="FIGDIR/small/669459v1_ufig1.gif" ALT="Figure 1"> View larger version (50K): org.highwire.dtl.DTLVardef@1ae8277org.highwire.dtl.DTLVardef@1f787ceorg.highwire.dtl.DTLVardef@1f51fd6org.highwire.dtl.DTLVardef@1fd3439_HPS_FORMAT_FIGEXP M_FIG C_FIG HighlightsO_LIDietary soy promotes T follicular helper (Tfh) cell and IgA responses in the Peyers patches of weaning mice. C_LIO_LISoy enhances the colonization of two key commensals, Limosilactobacillus reuteri and Muribaculum intestinale, in the small intestine. C_LIO_LIThese two bacteria synergize to drive mucosal immunity: L. reuteri provides cognate antigens, while M. intestinale provides an adjuvant signal by promoting IL-1{beta} production from myeloid cells. C_LIO_LISoy-induced IgA is polyreactive and protects against Salmonella infection. C_LI

immunology↗