We further explored the distribution and trends in the published documents dealing with the various hallmarks of aging (Figure ). The cellular senescence is clearly the aging attribute attracting most attention (Figure ). This should come as no surprise since cellular senescence is the aging denominator closely related to all other aging features (Figure ). It has been also connected to multiple age-related disorders, including cancer, diabetes, osteoporosis and osteoarthritis, cardiovascular disease, stroke, Alzheimer's disease and other dementias; furthermore, it has also been linked to deteriorations in eyesight, mobility, and cognitive capability. With respect to the annual trends in the aging hallmarks related publications, steady annual growth has been seen in those related to the stem cell exhaustion, altered intercellular communication, impaired autophagy, and especially dysbiosis (Figure ). Indeed, the extreme significance of gut microbiome in multiple aspects of human health is recently becoming well renowned and a hot topic in scientific research. Substantial data suggest the gut microbiome plays a role in virtually all physiological processes in the human body, including metabolism and immune homeostasis. Alterations to these processes can disturb the balance in the microbiome -a process termed dysbiosis -and trigger a range of pathological processes fundamental to mental health, metabolism, including multiple age-related diseases. 526 We examined also the distribution and trends in the published documents dealing with prominent anti-aging strategies (Figure ). The physical exercise comes up as the most studied approach, along with the metabolic manipulation (Figure ). This can be well anticipated considering the fact that these strategies are the ones related with the highest number of aging attributes (Figure ). Indeed, physical exercise has been well justified as one of the particularly effective and highly recommended anti-aging practice. Regular physical activity of the elderly has a proven vital role at a multisystem level, avoiding muscle atrophy, mending or maintaining cardiorespiratory health and cognitive performance, and boosting metabolic activity. Next, the inhibition of the mTOR pathway has been shown to exhibit profound effects on longevity and age-related phenotypes across a wide variety of organisms. With respect to the annual trends in the anti-aging strategies related publications, parabiosis (blood exchange) attracts substantial recent attention (Figure ). It has been suggested that blood exchange reverses the age-associated decline by targeting multiple attributes of aging including stem cell exhaustion, cellular senescence, altered intercellular communication, and chronic inflammation (Figure ). A steady growth in the number of recent publications have been documented with respect to the prebiotic/probiotics and fecal transplantation as well (Figure ). Multiple studies have conveyed evidence that microbiota-targeted interventions can have a strong therapeutic power not only for ageassociated diseases, but also for delaying aging and stimulating longevity. Indeed, longevity has been correlated to certain bacteria phyla alterations: Firmicutes rearrangement and Proteobacteria enrichment, decrease in Faecalibacterium prausnitzii and elevation of Eubacterium limosum. Furthermore, microbiota composition can be intensely modulated by activities and interventions including diet, probiotics/prebiotics/synbiotics, physical activity, drugs, and psychological stress. Fecal transplantation is another recently emerging intervention being looked at for a wide range of conditions including pathologies commonly associated with aging such as diabetes, metabolic syndrome, atherosclerosis, and neurodegenerative diseases. Remarkably, recent animal studies showed that, similarly to blood exchange, transfer of young donor microbiota into older animals can reverse age-related central nervous system and retinal inflammations, and cytokine signaling, effects which are coincident with increased intestinal barrier permeability. 527 Thus, microbial modulation emerges as therapeutically beneficial in preventing inflammation-associated tissue decay in later life. 527 Next, we explored the correlations between the hallmarks of aging and the anti-aging strategies as reflected by the number of documents in the CAS Content Collection (Figure ). Along with some foreseeable strong correlations such as stem cell exhaustion -stem cell therapies, lipid metabolic disorders -metabolic manipulations, impaired autophagy -autophagy enhancement, cellular senescence -senotherapy, and dysbiosis -prebiotic/probiotic/fecal transplantation, there are some less anticipated and instructive: