Microbiota Transplant Therapy for Pulmonary Arterial Hypertension: Early Safety and Feasibility Study

Pulmonary arterial hypertension (PAH) is a chronic disease characterized by pulmonary vascular remodeling of precapillary pulmonary arteries resulting in obstruction, increased pulmonary vascular resistance, right-sided cardiac failure, and ultimately death. Although pharmacologic therapies have been developed, these modestly improve cardiac function and primarily act to improve symptoms and quality of life; therefore, PAH remains a very lethal disease. Perivascular lung inflammation drives these vascular changes in PAH. This inflammatory profile could be driven by an imbalance of pro- and anti-inflammatory intestinal microbial metabolites, cytokines, other mediators, and/or direct effects of circulating bacteria all stemming from dysbiosis, gut-barrier dysfunction, and possibly, decreased hepatic filtration. Because PAH is characterized by a microbiome distinct from healthy controls, the investigators hypothesize that intestinal microbiota transplant (IMT) will help to reduce severity of PAH and improve quality of life, and that the healthy microbiome may exert these effects by decreasing inflammation. In this pilot clinical trial, the investigators aim to test the safety and feasibility of IMT from healthy donors into patients with PAH. Additionally, in the exploratory objectives, the investigators will obtain limited data to study pharmacokinetics of IMT, including engraftment and stability of donor intestinal microbiota, and pharmacodynamics to include circulating microbial products and markers of inflammation. Proposed circulating markers that may be assessed include interleukin-6, C-reactive protein, soluble CD14, lipopolysaccharide (LPS), phenylacetylglutamine, trimethylamine N-oxide, intestinal fatty acid binding protein, zonulin, claudin, short-chain fatty acids (SCFAs), tumor necrosis factor-α, interleukin-1β, and transforming growth factor-β.