Immunostimulating Commensal Bacteria and Their Potential Use as Therapeutics

Abstract

The gut microbiome is intimately intertwined with the host immune system, having effects on the systemic immune system. Dysbiosis of the gut microbiome has been linked not only to gastrointestinal disorders but also conditions of the skin, lungs, and brain. Commensal bacteria can affect the immune status of the host through a stimulation of the innate immune system, training of the adaptive immune system, and competitive exclusion of pathogens. Commensal bacteria improve immune response through the production of immunomodulating compounds such as microbe-associated molecular patterns (MAMPs), short-chain fatty acids (SCFAs), and secondary bile acids. The microbiome, especially when in dysbiosis, is plastic and can be manipulated through the introduction of beneficial bacteria or the adjustment of nutrients to stimulate the expansion of beneficial taxa. The complex nature of the gastrointestinal tract (GIT) ecosystem complicates the use of these methods, as similar treatments have various results in individuals with different residential microbiomes and differential health statuses. A more complete understanding of the interaction between commensal species, host genetics, and the host immune system is needed for effective microbiome interventions to be developed and implemented in a clinical setting.

Microbiome manipulation – the future of inflammatory skin disease treatment?

“…Not only microorganisms but also different microbial compounds (vitamins) and metabolic products play an important role in the interaction of the microbiome with the immune system. Any sort of changes in the gut microbiome composition can potentially lead to some sort of inflammation, which manifest on the skin as well (McCuaig & Goto, 2023). Several therapeutic strategies therefore strive to improve the well-being of the gut microbiome and fortify its ability to remain in balance, indirectly contributing to skin health as well.…”

“…The most common prebiotics are considered indigestible fibers, which remain undigested by the host and can only be fermented by commensal bacteria in the lower gastrointestinal tract. The benefits of these prebiotics are typically associated with the stimulation of short chain fatty acids (SCFAs) producing bacteria(Costa et al, 2021), but they may also improve immune response through the production of immunomodulating compounds and secondary bile acids and training the immune system by providing microbe-associated molecular patterns (MAMPs)(McCuaig & Goto, 2023). The pectins, for example, have been found to promote SCFA production, particularly acetate.…”