Role of gut microbiota in aging processes

This review examines the fundamental role of intestinal microbiota in modulating aging processes. According to current data, age-related microbiome changes are not a consequence, but an active mechanism of aging, determining individual developmental trajectory along the path of «successful» or pathological aging. Primary focus is on analysis of cause-and-effect relationship between dysbiosis and systemic aging. Age-related disruption of microbiota (decreased diversity, reduced amount of <i>Bifidobacterium</i> and <i>Akkermansia muciniphila</i>, butyrate deficiency) leads to disruption of intestinal barrier, lipopolysaccharide translocation, and chronic systemic inflammation through TLR4/NF-κB pathway activation. This cascade of pathological processes causes immune senescence and underlies major geriatric syndromes and age-associated diseases. This review provides a detailed analysis of dysbiosis influences on various body systems: neurodegenerative diseases via the gut-brain axis, sarcopenia via suppressed muscle protein synthesis, type 2 diabetes via impairment of insulin resistance, cardiovascular disease via TMAO production, and osteoporosis via impaired bone metabolism. Particular attention is paid to unique microbiota profile in centenarians, where combination of dysbiosis and preservation of specific symbionts (<i>Christensenellaceae</i>, <i>Akkermansia muciniphila</i>) is thought to promote healthy longevity. The article concludes by substantiating potential for therapeutic modification of microbiota as a strategy for correcting the manifestations of aging.