1. Propionate as a health-promoting microbial metabolite in the human gut
Elham Hosseini, Charlotte Grootaert, Willy Verstraete, Tom Van de Wiele Nutr Rev. 2011 May;69(5):245-58.doi: 10.1111/j.1753-4887.2011.00388.x.
Propionate is a major microbial fermentation metabolite in the human gut with putative health effects that extend beyond the gut epithelium. Propionate is thought to lower lipogenesis, serum cholesterol levels, and carcinogenesis in other tissues. Steering microbial propionate production through diet could therefore be a potent strategy to increase health effects from microbial carbohydrate fermentation. The present review first discusses the two main propionate-production pathways and provides an extended gene-based list of microorganisms with the potential to produce propionate. Second, it evaluates the promising potential of arabinoxylan, polydextrose, and L-rhamnose to act as substrates to increase microbial propionate. Third, given the complexity of the gut microbiota, propionate production is approached from a microbial-ecological perspective that includes interaction processes such as cross-feeding mechanisms. Finally, it introduces the development of functional gene-based analytical tools to detect and characterize propionate-producing microorganisms in a complex community. The information in this review may be helpful for designing functional food strategies that aim to promote propionate-associated health benefits.
2. Clascoterone for treatment of acne
Cyriac Manjaly, Jeremy Martinez, John Barbieri, Arash Mostaghimi Drugs Today (Barc). 2023 Feb;59(2):71-81.doi: 10.1358/dot.2023.59.2.3507749.
Clascoterone is a novel topical antiandrogen medication approved for the treatment of acne. Conventional oral antiandrogen treatments targeting acne such as combined oral contraceptives and spironolactone exert systemic hormonal effects which commonly preclude their usage in male patients while hampering their application in certain female patients. In contrast, clascoterone is a first-in-class antiandrogen proven to be both safe and effective for female and male patients above the age of 12. Outside of occasional localized skin irritation, clascoterone is usually well tolerated, however, some adolescents in a phase II clinical trial experienced biochemical evidence of HPA suppression, which resolved after discontinuing treatment. In this review, we provide an overview of clascoterone including its preclinical pharmacology, pharmacokinetics and metabolism, safety, clinical studies and indications.
3. Syntrophic propionate-oxidizing bacteria in methanogenic systems
Maria Westerholm, Magdalena Calusinska, Jan Dolfing FEMS Microbiol Rev. 2022 Mar 3;46(2):fuab057.doi: 10.1093/femsre/fuab057.
The mutual nutritional cooperation underpinning syntrophic propionate degradation provides a scant amount of energy for the microorganisms involved, so propionate degradation often acts as a bottleneck in methanogenic systems. Understanding the ecology, physiology and metabolic capacities of syntrophic propionate-oxidizing bacteria (SPOB) is of interest in both engineered and natural ecosystems, as it offers prospects to guide further development of technologies for biogas production and biomass-derived chemicals, and is important in forecasting contributions by biogenic methane emissions to climate change. SPOB are distributed across different phyla. They can exhibit broad metabolic capabilities in addition to syntrophy (e.g. fermentative, sulfidogenic and acetogenic metabolism) and demonstrate variations in interplay with cooperating partners, indicating nuances in their syntrophic lifestyle. In this review, we discuss distinctions in gene repertoire and organization for the methylmalonyl-CoA pathway, hydrogenases and formate dehydrogenases, and emerging facets of (formate/hydrogen/direct) electron transfer mechanisms. We also use information from cultivations, thermodynamic calculations and omic analyses as the basis for identifying environmental conditions governing propionate oxidation in various ecosystems. Overall, this review improves basic and applied understanding of SPOB and highlights knowledge gaps, hopefully encouraging future research and engineering on propionate metabolism in biotechnological processes.
