Beschreibung:
The gut is the main location for immunological regulation and is influenced by the flora that reside there. This flora, also known as the gut microbiome, is necessary for maintaining immune health and disruptions in the microbiome result in systemic, metabolic and inflammatory disorders including obesity, diabetes, and cardiovascular disease. Therefore a possible approach to treat these disorders involves modulating the gut microbiome through the administration of probiotics. Probiotics are defined by the World Health Organization as, “live microorganisms that confer a health benefit to the host when consumed in adequate amounts.” Data from our laboratory indicate that a specific strain of probiotic, Bifidobacterium animalis sub‐species lactis 420 (B420), reduces the extent of cardiac injury following ischemia/reperfusion in a mouse model of myocardial infarction. This cardioprotection is attributed to a reduction in cardiac inflammation, however, it is unclear precisely how B420 mediates this effect. Here, we hypothesize that the mechanism of gut‐dependent cardioprotection observed in vivo is through epigenetic and post‐translational regulation of intestinal, epithelial and immune cell function. We further hypothesize that the initiation of this mechanism is not uniform throughout the GI tract, and may be regionally localized. To this end, we developed a system to track the probiotic in the gut to better understand where and how they interact with the gut microbiome. Indocyanine Green (ICG) is a near infrared(NIR) stable aqueous, sterile, fluorescent, and clinically effective agent. In this study we aim to develop an inexpensive and effective method to track B420 bacteria in the gut‐microbiome. ICG was cultured with B420 and analyzed with LagoX imaging software at NIR wavelengths. ICG did not inhibit growth of B420 culture, and was a suitable reagent for labeling B420 bacteria. The ICG‐B420 co‐culture was gavaged in a treatment group of C57BL/6 mice at 2mg/kg, while control mice received B420 only. The GI tract was imaged in vivo and ex vivo bioluminescence. Bacterial genomic DNA from C57BL/6 treated and untreated mice gut epithelia was quantified using B420 primers and quantitative PCR(qPCR), and verified localization of bacteria colonization observed during fluorescent imaging.Support or Funding InformationCardiovascular Training Grant in Biomedical Engineering NIH T32 training grant