Gut Microbial Changes, An Ageing Perspective
The human body contains a wide variety of bacterial species, and because the human gut harbors the majority of microbes, it can be considered a "microbial organ."
All the microbes in the gut are collectively known as “gut microbiota” and genomes associated with them represent the “gut microbiome.”
The microbiota is not a uniform population of microorganisms; it is made up of a complex network of microbial communities that interact with one another and the human body in ways that affect our health.
As does its role in metabolism and immune system regulation, gut microbial diversity declines with age. This allows opportunistic pathogens to invade and inflame the gut, resulting in a variety of diseases ranging from low-grade chronic illnesses to those requiring hospitalization and even death.
Diet plays a role as a microbiota manipulator throughout life, and this may be especially important in older adults. Broad-spectrum antibiotics almost certainly have a negative impact on gut bacteria.
It is established that probiotic supplementation has a significant potential to restore gut microbiota diversity and improve immune function.
Gut microbiota is established during birth and evolves with age, mostly maintaining a commensal relationship with the host. A growing body of clinical evidence suggests that the gut microbiota and the immune system have a complex relationship. The gut microbiota becomes significantly imbalanced with age, resulting in an impaired immune response.
Antimicrobial therapy is commonly used to treat infections, but it can also result in the loss of normal gut flora. This unfavorable gastrointestinal modulation can be reversed by using antibiotics sparingly and in moderation and supplementing with prebiotics and probiotics.
A healthy intestinal tract remains relatively stable throughout adulthood, but with age, perturbations occur due to exogenous factors such as antibiotic use and diet, as well as endogenous factors such as cellular stress.
Major physiological changes associated with aging include changes in gut microbial composition (dysbiosis), immune responses, and metabolism, all of which can lead to gastrointestinal (GI) tract-related inflammatory conditions and autoimmune disorders.
Modulation of Gut Microbiota for Health
Diet influences the establishment and development of stable gut microbiota and can aid in their modulation. Because of the high prevalence of malnutrition in older adults, dietary manipulation could be beneficial.
SCFA production in the gut of older adults is decreasing due to a significant shift in bacterial composition and malnutrition. This contributes to a decrease in anti-inflammatory response, which leads to an increase in infections.
A high-fiber diet is widely recommended for adults and the elderly because it increases SCFA production and lowers intestinal pH, reducing pathogenic bacteria colonization.
This information was compiled from a research article published in BioMed research international in February 2018.
Many specific therapies have been proposed for treating dysbiosis, such as the use of prebiotics, probiotics, and synbiotics (a combination of probiotics with prebiotics).
Several clinical studies demonstrated the ability of probiotics in modulating gut bacteria in infants, adults, and older adults.
These studies indicated an increase in SCFA production and an improvement in the immune system. Prebiotics alone was shown to improve the gut microbiota and help in the production of SCFA.
To control recurring infections, the concept of fecal microbiota transplantation (FMT) was introduced. A fecal sample from a healthy donor is chosen and infused into diseased patients via colonoscopy, endoscopy, sigmoidoscopy, or enema. FMT provided a 90% benefit as a treatment option for diarrhea, and many researchers have demonstrated its efficacy in IBD, Crohn's disease, and ulcerative colitis.
Making probiotics a regular part of your diet will help maintain gut symbiosis and protect against age, diet, or antibiotic-induced gut dysbiosis.