“…In similar analyses, the genus Peptococcaceae , identified to both negatively contribute to TMAO levels and in vivo clot formation, was remarkably decreased in old mice versus young mice ( Zhu et al., 2016 ). As shown in Figure 2 B, aging was associated with a significant increase in the proportions of Desulfovibrio , known for producing trimethylamine (TMA), a precursor of TMAO ( Zeisel and Warrier, 2017 ), and for modulating the production of proinflammatory cytokines ( Zhang-Sun et al., 2015 ), and of genera Ileibacterium , in particular I. valens , a genus which is highly abundant in the intestinal microbiota of mice with heart failure ( Khannous-Lleiffe et al., 2020 ). In line, these taxonomic shifts were accompanied by age-dependent alteration in microbiota-derived metabolites levels, so that age is known to be both significantly positively associated with plasma TMAO levels (p < 0.0001, Figure 2 C) and negatively associated with fecal levels of SCFAs, acetate, and propionate, seen in old versus young mice (for both p < 0.0001, Figures 2 D and 2E).…”