Effects of Probiotic Metabolites on iPSC Proliferation, Differentiation and Maturation

Abstract

Recent studies discovered that bacteria can maintain and benefit human health. Probiotics, the live and benign bacteria, in yogurt could modulate the bacterial profiles in human gut, and thus have health benefits. We examined five different brands of yogurts often sold in the supermarkets (Oikos, Stonyfield, Yoplait, Chobani and Activia) by Gram‐staining bacteria, culturing bacteria, and identifying certain bacteria by PCR and DNA sequencing with bacterial fingerprinting 16s rRNA gene. We found that not all yogurts are produced equally, and some yogurts, such as Chobani Yogurt, contain more viable bacteria and they lived longer than bacteria from other brands. Sequencing analysis identified the presence of different probiotic bacterial strains in different yogurts. To evaluate the probiotic health benefits, we determined the effects of probiotic metabolites on human cardiac fibroblast derived induced pluripotent stem cells (iPSC). Using conditioned media from probiotic bacteria Lactobacillus reuteri (LRCM), we found that bacterial metabolites induced iPSC proliferation at lower doses while inhibited iPSC proliferation at higher doses. Additionally, the proliferating cell nuclear antigen PCNA was up‐regulated in iPSCs treated with LRCM and more interestingly, LRCM treatment potentiated the expression of pluripotent stem cell factors OCT4, SOX2 and NANOG in iPSCs. Consistently, a defined bacterial metabolite‐short chain fatty acid, sodium butyrate, had similar effect on iPSC proliferation. Furthermore, LRCM and butyrate exhibited similar effects on the differentiation of iPSC into cardiomyocytes, as indicated by myocyte beating and analysis of myocyte transcript markers. The results of cardiac myocyte differentiation and maturation will be discussed at the meeting as the experiments are ongoing. In summary, we have determined that probiotics in different brands of yogurts are different in viability and stains. Using conditioned media from a probiotic bacteria and a defined bacterial metabolite, we have further demonstrated the direct effects of probiotic metabolites on iPSC proliferation, differentiation and maturation. These studies have established a good platform to further study how the yogurt changes human microbiome and affects human health and disease.