Hopefully, new life-long longitudinal studies or continuations of existing ones will cover this gap.Īt present, the best way of grasping the adaptive pattern of human GM as humans age is represented by cross-sectional studies embracing a wide age range in well-defined populations that are relatively homogeneous in genetics and lifestyles.
BAHN HUA THANON AS POTENT AS SUPER STRAIN FULL
To date, this kind of analyses has not been possible because attention towards the GM is quite a recent development, while the most reliable and robust longitudinal studies have not collected stool samples across the full life span of individuals. In this elaborate scenario, the most informative approach for understanding the role of the GM in its lifelong maintenance of host homeostasis would clearly be by longitudinal studies monitoring individuals over time (years and decades) to identify and follow the specific trajectories of their age-related GM modifications. Thus, a healthy adult GM structure is properly defined as a set of many possible configurations which, even when differing in composition, share a comparable degree of diversity and evenness (meaning the number of species with an equal distribution in the ecosystem), and the ability to preserve the homeostasis of the human host. Indeed, the GM has emerged as a dynamic community able to adapt its composition and functionality to the varying conditions in which the human host lives to meet the changing demands of host metabolism. This adaptive nature of the GM is functional to calibrating the immune and metabolic pathways in response to individual needs, and has a profound impact on health and disease. These factors over a lifetime impinge on the GM, resulting in huge variability and heterogeneity of this ecosystem in human beings.
The composition of the GM is affected by a plethora of individual, population and environmental variables, e.g., age, gender, genetic background, biography (type of delivery, breastfeeding or formula feeding, use of antibiotics), immuno-biography (lifelong immunological experience) and geography (ethnicity, cultural habits, nutrition). This niche establishes a complex, multi-species apparatus in which every occupant plays a role and modulates its own activity in response to signals coming from inside and outside the human host. The human gut microbiota (GM) is a highly diverse ecosystem made up of trillions of bacteria populating the gastrointestinal tract. Finally, it is argued that longitudinal studies combining metagenomics sequencing and in-depth phylogenetic analysis with a comprehensive phenotypic characterization of centenarians and patients using up-to-date omics (metabolomics, transcriptomics and meta-transcriptomics) are urgently needed. We likewise address the role of GM in neurodegenerative diseases such as Parkinson’s and Alzheimer’s, and its possible therapeutic use, taking advantage of the fact that centenarians are characterized by an extreme (healthy) phenotype versus patients suffering from age-related pathologies. The feedback impact of age-associated GM variation on the GM–brain axis and GM metabolomics is also discussed.
BAHN HUA THANON AS POTENT AS SUPER STRAIN DRIVERS
The current review focuses on the role of population, gender and host genetics as possible drivers of GM modification along the human aging process. We argue that comparison among studies on centenarians-the best model of healthy aging and longevity-recruited from different geographical areas/populations (different genetics and dietary habits) can help to disentangle the contribution of aging and non-aging-related variables to GM remodeling with age. However, the basic question of how much these changes may be ascribed to variables such as population, diet, genetics and gender, and/or to the aging process per se is still largely unanswered. The GM is highly dynamic, being sensitive to environmental stimuli, and its composition changes over the host’s entire lifespan.
The gut microbiota (GM) is a complex, evolutionarily molded ecological system, which contributes to a variety of physiological functions.