Gut Microbiome’s Key Role In Aging And Longevity –

Of all the scientific and medical breakthroughs in our lifetimes, one of the most exciting of all has been discovery of the microbiome, the colonies of bacteria that thrive within each of us. Like a fingerprint, each person’s microbiota is unique. The gut microbiome is an integral component of the body, but its importance in the human aging process is unclear. Increasing evidence suggests that the gut microbiome lies at the core of many age-associated changes, including immune system dysregulation and susceptibility to disease, according to research published in Nature Metabolism (February 2021). This column will briefly examine how in this research, scientists connected gut microbiome to healthy aging and longevity.

The microbiome market includes probiotics, prebiotics and medical foods, and is expected to grow substantially during the next several years. Probiotics hold the largest market share, owing to its proven benefits in gut microbiota and health of the patient (Market Study Report LLC, Delaware. 302-273-0910). Analysts credit market growth to consumers’ heightened awareness of preventive health care, as well as their increasing knowledge of the impact that the gut microbiome has on holistic health.

The gut microbiome is an important part of our physiology. The body needs a healthy balance of good intestinal bacteria. Scientists have discovered that specific gut bacteria considered beneficial to human health are dominant in the gut microbiome of Italian and Chinese nonagenarians (90-99 years old), centenarians (99-104 years old), and super-centenarians (105 years and older), all strong evidence for a functional link between healthy gut microbiome and healthy aging.

These bacteria are frequently depleted by consumption of antibiotics, steroids, acid-blocking medicines, laxatives, artificial sweeteners, processed foods, poor diet, stress and sedentary lifestyle. Yet, the right mix of these bacteria prevent a host of diseases. The bacteria diversity and overall balance are intimately related to our states of health and disease.1

The type of bacteria living on the skin and in the gut are fundamentally different according to Sophie Shotter MD. The bacteria in the gut are predominantly anaerobic, meaning they can survive without oxygen. Skin’s microbiome largely depends on the environment, whereas gut microbiome depends on the location within the gut, as well as extrinsic factors such as diet. More than 70% of the human immune system is found in the gut lining.2 When the gut microbiome is balanced and thriving, the body digests and absorbs nutrients efficiently while excreting toxins and pathogens, before they are absorbed into the bloodstream.

According to Leslie Baumann MD, a balanced gut microbiome contributes to overall wellness, including skin health. In contrast, an unbalanced microbiome, known as “dysbiosis,” has been connected with certain autoimmune diseases such as diabetes, rheumatoid arthritis, muscular dystrophy and fibromyalgia. Chronic dysbiosis of the gut microbiome has been implicated in leaky gut syndrome, inflammation, weight gain and it also influences the health or appearance of skin.3

In the largest and most detailed study of its kind, researchers explored the gut microbiome’s link to diet and disease. The research was conducted by the Institute for Systems Biology (ISB) and collaborators from Oregon Health and Science University, University of California San Diego, University of Pittsburgh, University of California Davis and University of Washington. Their research was supported by the National Institute on Aging.

Researchers analyzed gut microbiome and clinical data from more than 9,000 people between the ages of 18 and 101. The data showed that gut bacteria in healthy old people becomes increasingly unique as they age while their microbiome generates life extending chemicals. Researchers identified distinct signatures in the gut microbiome that are associated with either healthy or unhealthy trajectories. In healthy individuals, gut microbiomes become increasingly unique, diverging in different ways that are specific to the individual compared to unhealthy individuals. The uniqueness is strongly associated with microbially-produced amino acid derivatives circulating in the bloodstream, suggestive of life-extending chemicals. It can be safely concluded that microbiomes can be used to predict survival in a population of older individuals, according to the experts. Study conclusions further say that adult gut microbiomes continue to develop with advanced age in healthy individuals, but not in unhealthy ones.

According to the ISB’s Nathan Price PhD, this research is exciting work that will have major clinical implications for monitoring and modifying gut microbiome health throughout a person’s life. Researchers concluded that participants who consumed lots of healthy, minimally processed, plant-based foods had higher levels of beneficial gut microbes. An abundance of these favorable gut microbes was associated with a lower risk of developing conditions such as obesity, type-2 diabetes and cardiovascular disease. The study further suggests, adjusting your diet to support your gut microbiome may be pivotal for long and healthy life.

The study concluded that little of the microbiome is pre-determined by heredity; and therefore, it can be modified by diet. A microbiome that is healthy for a 20-year-old is not at all healthy for an 80-year-old. It seems that it’s good to have a changing microbiome when you are old. It means that the bugs that are in your system are adjusting appropriately to an aging body.4 The researchers could not be certain whether changes in the gut microbiome helped to drive healthy aging or vice versa, The people who had most changes in their microbial compositions tended to have better health and longer lifespans. They also had better physical health, demonstrating faster walking speeds and greater mobility. ISB’s Tomasz Wilmanski PhD, found that people whose gut microbes did not undergo much change as they got older, were in poorer health. For example, they had higher cholesterol and triglycerides and lower levels of vitamin D. They were also less active and could not walk as fast. They used more medications and they were nearly twice as likely to die during the study period. The researchers speculated that some gut bugs that might be innocuous or beneficial in early adulthood could turn harmful in old age.

Diet has a substantial impact on the composition of microbiome. The use of prebiotics and probiotics has been shown to help stabilize the gut microbiome and ultimately have a positive effect on the skin, including improving conditions like skin aging, acne, atopic dermatitis and rosacea.5 Eating more fiber and fish, consuming less highly processed foods and staying physically active is the best way to remain healthy.

It is becoming clear that microbiome diversity is very important for human health. Extrinsic factors such as lifestyle and diet are shown to be essential for healthy aging, and ultimately, longevity. Scientists are just beginning to understand the important role of the bacterial colonies that thrive inside our gut. There is a lot more to our digestive systems than absorbing vitamins and minerals.


  1. Khanna S. et al Mayo Clin Proc.2014, 89(1) :107-14
  2. Vighi G, et al Clin. Exp Immunol. 2008:153 (supp/1): 3-6.
  3. J. Sanford et al, Seminars on immunology 25, #5 November 2013, 370-77
  4. What goes on in the Gut, A. O’Connor, NY Times 3/23/21
  5. K. Baqerizo N. et al, J. of American Academy of Dermatology 71, No. 4 June 2014, 821-41

Navin Geria
Chief Scientific Officer
Ayurderm Technologies, LLC
Navin Geria, former Pfizer Research Fellow is a cosmetic and pharmaceutical product development chemist and the chief scientific officer of AyurDerm Technologies LLC, which provides Ayurvedic, natural and cosmeceutical custom formulation development and consulting services to the spa-wellness-dermatology industries. He has launched dozens of cosmeceutical and ayurvedic anti-aging products. Geria has more than 30 years of experience in the personal care industry and was previously with Clairol, Warner-Lambert, Schick-Energizer, Bristol-Myers and Spa Dermaceuticals. He has nearly 20 US patents and has been published extensively. Geria edited the Handbook of Skin-Aging Theories for Cosmetic Formulation Development focus book published in April 2016 by Harry’s Cosmeticology. He is a speaker, moderator and chairman at cosmetic industry events. 

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