Reviewing What is Known of the Role of the Gut Microbiome in Aging
A growing body of evidence suggests that composition of the gut microbiome - and changes in that composition - may be as influential on long-term health, aging, and age-related disease as well explored lifestyle factors such as exercise. Given the ability to cheaply and accurately determine the identity and size of microbial populations making up the gut microbiome via 16s rRNA sequencing, researchers are finding that many specific aspects of the microbiome both change with age and correlate with specific age-related diseases. The next step is to build robust approaches to producing permanent change in the gut microbiome, such as that achieved via fecal microbiota transplantation from a young donor to an old recipient, but with greater control over exactly what is delivered and the intended outcome.
With the introduction of novel molecular biological techniques and advances in next-generation sequencing technologies, we finally have a snapshot of the gut microbiome and its taxonomical and functional constituents. Various studies have been conducted on healthy elderly individuals to characterize their gut microbiome composition and identify alterations that help delay the onset of age-associated disorders. Although aging is a complex biological process that has yet to be fully understood, we have an increasing volume of evidence supporting the existence of a dialogue between the gut microbiome of a host and its aging process. Aging brings about changes in the gut microbiome, disrupting its balance and functionality, which can accelerate senescence through inflammatory processes and reduced production of beneficial metabolites.
Advancements in the different "omics" fields have provided us with a clear understanding of various host-microbe interactions and their influences on aging. Enrichment of certain taxa, such as Bifidobacterium, Christensenellaceae, and Akkermansia, has been shown to promote longevity and improve quality of life during senescence. To improve the gut microbiome and encourage healthy aging, techniques such as fecal microbiome transplantation (FMT) and oral probiotic treatment have been used. Administration of prebiotics and probiotics may mitigate age-related alterations linked to sarcopenia and longevity.
Since age-related disorders are known to increase intestinal permeability, regaining intestinal permeability by FMT may be a regenerative and successful medicinal technique in producing stem cells for the elderly. Nevertheless, more research is needed to determine whether FMT to old recipients from young donors restores the ability of stem cells to self-renew, regenerate, and differentiate, thereby improving lifespan. To pave the way for discovering therapeutic medications for extending lifespan and treating disorders linked to aging, more research into the interactions between intestinal stem cells and the microbiome is necessary.