Maternal exposure to soy diet reduces atheroma in hyperlipidemic F1 offspring mice by promoting macrophage and T cell anti-inflammatory responses

Long-term administration of Tetragenococcus halophilus No. 1 over generations affects the immune system of mice

Japanese people have been consuming miso soup over generations; it is beneficial for health and longevity. In this study, Tetragenococcus halophilus No. 1 in miso was found to possess salient immunomodulatory functions. Recently, we also demonstrated its effect on boosting immunological robustness. Although the consumption of miso is suggested to affect health over generations, such a long-term experiment has not been conducted until now. Thus, we evaluated the effects of miso-derived T. halophilus No. 1 over generations on the immune system of mice. As the generations increase, the proportion of germinal center B cells tends to increase. Furthermore, we found that CD4⁺ T cells expressing CD69, an activation marker, were increased in the third generation of mice. In addition, the proportion of follicular helper T cells and regulatory T cells tended to increase. Among the subsets of CD4⁺ T cells in the fourth generation, effector T cells and effector memory T cells tended to increase. In contrast, central memory T cells and naive T cells decreased. Moreover, autoimmunity was suppressed by long-term administration of T. halophilus No. 1. Based on these findings, we believe that the long-term administration of T. halophilus No. 1 over generations promotes immune activation and tolerance and enhances immunological robustness.

Maximizing the Estrogenic Potential of Soy Isoflavones through the Gut Microbiome: Implication for Cardiometabolic Health in Postmenopausal Women

Soy isoflavones have been suggested as an alternative treatment for managing postmenopausal symptoms and promoting long-term health due to their structural similarity to mammalian estrogen and ability to bind to estrogen receptors. Among all soy isoflavones and their metabolites, (S)-equol is known for having the strongest estrogenic activity. Equol is a metabolite of the soy isoflavone daidzein produced through intestinal bacterial metabolism. However, more than half of the human population is not able to produce equol due to the lack of equol-producing bacteria in their gastrointestinal tract. The interpersonal variations in the gut microbiome complicate the interpretation of data collected from humans. Furthermore, because rodents are efficient equol-producers, translatability between rodent models and humans is challenging. Herein, we first summarized the current knowledge of the microbial conversion of daidzein to equol, its relation to health, and proposed the need for developing model systems by which equol production can be manipulated while controlling other known confounding factors. Determining the necessity of equol-producing capacity within a gut microbial community when consuming soy as a functional ingredient, and identifying strategies to maximize equol production by modulating the gut microbiome, may provide future therapeutic approaches to improve the health of postmenopausal women.