The aging of the microbiome, the collective bacteria, fungi, protozoa and viruses that live on and inside our bodies, has become a popular research topic in recent years.
The microbiome appears to influence aging
There has been increasing interest in the influence of this microbial community, especially those living in the gut, in the context of aging and disease.
The gut microbiome is a complicated community of microbial life that constantly changes and shifts in response to diet, lifestyle, and other stimuli. Studies have shown that there is a great deal of crosstalk between the microbiome, the immune system, and other parts of the metabolism. It is becoming increasingly clear that the microbiome is a mediator that stands between diet and health.
Unfortunately, as we age, the microbiome changes with a tendency for beneficial bacteria to decline and for harmful ones to increase. An increasing number of researchers are engaged in investigating those changes and countering them, but despite considerable progress in the last few years, understanding these changes is still a relatively new area of research that has yet to reach maturity.
The researchers of today’s highlighted review have proposed that a new term, “gerobiotics“, be used to describe the bacteria that beneficially influence the aging processes to potentially slow, delay, or reverse some aspects of aging and increase the healthspan or even lifespan of the host [1].
The review provides a summary of the past research in this field and also the needs, challenges, and direction that this proposed gerobiotics field might take. The researchers also consider and suggest how biomarkers and gerobiotic interventions might be developed as part of this new field.
Aging is recognized as a common risk factor for many chronic diseases and functional decline. The newly emerging field of geroscience is an interdisciplinary field that aims to understand the molecular and cellular mechanisms of aging. Several fundamental biological processes have been proposed as hallmarks of aging. The proposition of the geroscience hypothesis is that targeting holistically these highly integrated hallmarks could be an effective approach to preventing the pathogenesis of age-related diseases jointly, thereby improving the health span of most individuals. There is a growing awareness concerning the benefits of the prophylactic use of probiotics in maintaining health and improving quality of life in the elderly population. In view of the rapid progress in geroscience research, a new emphasis on geroscience-based probiotics is in high demand, and such probiotics require extensive preclinical and clinical research to support their functional efficacy. Here we propose a new term, “gerobiotics”, to define those probiotic strains and their derived postbiotics and para-probiotics that are able to beneficially attenuate the fundamental mechanisms of aging, reduce physiological aging processes, and thereby expand the health span of the host. We provide a thorough discussion of why the coining of a new term is warranted instead of just referring to these probiotics as anti-aging probiotics or with other similar terms. In this review, we highlight the needs and importance of the new field of gerobiotics, past and currently on-going research and development in the field, biomarkers for potential targets, and recommended steps for the development of gerobiotic products. Use of gerobiotics could be a promising intervention strategy to improve health span and longevity of humans in the future.
Conclusion
This review is a welcome addition to the area of microbiome research, and it would be great to see the near-future emergence of a gerobiotics field that seeks to identify pro-longevity bacteria and ways to reliably introduce them into our bodies.
In the meantime, there are already potential solutions to the age-related decline of microbiome diversity, though they are not for the faint-hearted. Fecal transplants have seen some success in animal studies, in which samples of young microbiome are transferred to older individuals via fecal matter that contains enough beneficial bacteria to “seed” the aged gut [2].
It may also be possible for probiotics to deliver the correct mixture of pro-longevity microbes to the aged gut microbiome, though this area of research is poorly understood at this time, and success has been limited so far.
It also might be potentially possible for prebiotics to deliver microbial enzyme inhibitors to the aged gut microbiome in order to block or reduce the production of deleterious bacterial metabolites such as TMA, the precursor of TMAO, which is potentially linked to vascular aging. This is an appealing path, as it targets the problematic metabolites and sidesteps the complexity of needing to take into account the complex interplay of thousands of types of bacteria.
Literature
[1] TSAI, Y. C., CHENG, L. H., LIU, Y. W., JENG, O. J., & LEE, Y. K. (2020). Gerobiotics: probiotics targeting fundamental aging processes. Bioscience of Microbiota, Food and Health.
[2] Bárcena, C., Valdés-Mas, R., Mayoral, P., Garabaya, C., Durand, S., Rodríguez, F., … & López-Otín, C. (2019). Healthspan and lifespan extension by fecal microbiota transplantation into progeroid mice. Nature medicine, 25(8), 1234-1242.
