Abstract 4141327: Alternate Day Fasting Attenuates Arterial Thrombotic Risk via Increasing Indole-3-propionic acid

Background: Arterial thrombotic disease has long been a crucial worldwide health concern. Metabolic disorders have been validated to enhance platelet reactivity, thereby augmenting the thrombotic risk. Recent investigations have highlighted the metabolic improving effect of alternate day fasting (ADF). However, its impact on thrombosis remains unclear. Hypothesis: We hypothesize that ADF may reduce arterial thrombotic risk through its metabolic modulatory effect. Aims: To investigate the effects of ADF on thrombogenesis and unravel its underlying mechanisms. Methods: Thirty male C57BL/6J mice fed with high fat diet (HFD) for 6 weeks were randomly allocated into 3 groups: HFD, ADF, or pair feeding, for another 6 weeks dietary intervention, while mice fed standard laboratory diet were set as control. In vivo carotid artery ferric chloride injury model and multiple ex vivo platelet function assays were utilized to assess the impacts of ADF on thrombogenesis and platelet reactivity. Fecal microbiota transplantation was performed to further explore the causal relationship between gut microbiota and ADF-mediating effects on thrombosis. Moreover, fecal metagenomic and plasma untargeted metabolomics analyses were conducted to identify the alterations of gut microbiota composition and metabolite profiles under ADF intervention. Results: Our study demonstrated that ADF ameliorated HFD-induced heightened platelet reactivity and thrombotic tendency in mice on a gut microbiota dependent manner. Indole-3 propionic acid (IPA), a gut microbiota-derived metabolite, was enriched under ADF and further identified as a crucial factor mediating the anti-thrombotic effect of ADF. Supplementation of IPA impeded platelet activation via suppressing intraplatelet Rho-GTPase cycle and its downstream signals, thereby alleviating thrombotic formation without affecting hemostasis. Of note, we demonstrated that plasma IPA was remarkably decreased in patients with acute arterial thrombotic events, which also exhibited a significant negative association with platelet reactivity. Conclusions: Our study uncovers the protective effect of ADF on thrombogenesis, providing mechanistic insights and a potential therapeutic strategy for arterial thrombotic diseases.