Written by: Dr. Raymond Cruz
The aging process is full of complexity, and many studies have been made in an attempt to understand the processes involved in it. Genetic and environmental factors play vital roles in its development. Recently, new techniques in cellular and molecular research have enabled scientists better understand the various hallmarks that lead to aging. These disturbances may predispose to various chronic disease, including cardiovascular disorders, infections, bowel diseases, autoimmune diseases, cancers, diabetes, obesity and neurodegenerative diseases. And one of the most recent findings is this: the type of bacteria and microorganisms that reside in our gastrointestinal tract can have profound and long-term effects on our health and well-being. The Microbiome, or the collective imprint of microorganisms in our bodies, have been shown to help in maintaining the balance of our body systems.
One of the most recent findings is this: the type of bacteria and microorganisms that reside in our gastrointestinal tract can have profound and long-term effects on our health and well-being.
Many clinical issues, such as concomitant exposure to multiple drugs and antibiotics, food intake, and the frequency of bowel movement are closely related with changes in microbiome composition, particularly in the gastrointestinal tract. All these contribute to the increased propensity for various infectious and gut-associated diseases by causing alterations in the microbiota (microorganisms in the body) of elderly people. The gut microbiota may be associated with inflammation and age-related chronic health conditions, and could serve as targets for modification in promoting health and well-being.
Most studies have revealed that highly processed foods, sugary diets, and overindulgence in alcoholic beverages harm the intestinal microbiota.
So when does the microbiome begin to influence human health? As soon as a newborn infant leaves the protective environment of the uterus, he or she may already be exposed to different microorganisms. Responses to these microbes during early life manifest during development. The microbiome keeps on fluctuating during different stages of life. It is largely influenced by whatever we take into our bodies. Most studies have revealed that highly processed foods, sugary diets, and overindulgence in alcoholic beverages harm the intestinal microbiota. While these deviations occur over time and are at first benign, certain changes could have an impact on our body’s defense mechanisms.
Our microbiota undergoes the most prominent deviations during infancy and old age. With an aging population worldwide, the prevalence of metabolic diseases has also radically increased. Dysbiosis, or an imbalance in the microorganisms making up the body, is known to be associated with aberrations in the digestive and absorptive processes. These elements can also lead to the progression of various metabolic diseases that are prevalent in old people such as adiposity, insulin resistance, fatty liver disease, atherosclerosis, and neurologic abnormalities.
Older people also have lower levels of Short Chain Fatty Acids, or SCFAs. A reduction in SCFA production has been found to be correlated with a lower fiber intake and antibiotic treatment during old age. Such decline in intestinal SCFA levels may favor intestinal populations of bacteria that cause chronic disease. Therefore, the reduced SCFAs levels in old age may increase susceptibility to inflammatory diseases. This results in gut-related diseases in old people.
Probiotics and prebiotics might prove to be promising candidates for developing dietary interventions for promotion and maintenance of healthy gut microbiota.
The idea of manipulating gut microbiota for healthy aging was put forward by Nobel laureate Elie Metchnikoff in the early 20th century. While a causal relationship has not yet been determined, the available evidence on the associations between gut microbiota, nutrition, and systemic inflammation suggest that dietary interventions for positively modulating the microbiota composition and diversity could help promote healthy aging and longevity. In this context, probiotics and prebiotics might prove to be promising candidates for developing dietary interventions for promotion and maintenance of healthy gut microbiota.
Probiotics are live microorganisms that, when administered in adequate amounts, confer a health benefit on the host. Prebiotics are non-digestible food ingredients which selectively stimulate the growth and activity of bacteria in the colon. The overall target of both probiotics and prebiotics is to restore and maintain the balance of the gut microbial ecosystem, which are crucial during old age. Since prebiotics positively affect probiotics, combining them as “synbiotics” for prevention as well as therapy are being proposed for better gut and overall health. Fermentation of prebiotics by probiotics, mainly Bifidobacteria and Lactobacilli, also increases the intestinal levels of SCFAs especially butyrate which have been shown to confer immune-modulating and anti-inflammatory effects. However, the available body of evidence is still too limited and inconsistent to interpret any substantial conclusion about the efficacy and working mechanisms of probiotics and prebiotics in the prevention of old-age related illnesses and immune-senescence. More clinical studies are warranted in this case.
Gross as it sounds, FMT is the transfer of a small amount of healthy donor’s feces into the intestinal tract of recipient or the patient. This approach has already shown promising results.
A novel approach called fecal microbiome transplantation (FMT) has gained considerable attention in recent years. Gross as it sounds, FMT is the transfer of a small amount of healthy donor’s feces into the intestinal tract of recipient or the patient. This approach has already shown promising results. Research is still in infancy regarding the safety, efficacy and validity of FMT. One of the main challenges would be the standardization of the technique so as to rule out any possible risk of infection. In the near future, we may see the advent of fecal material being introduced into our system to prevent and cure disease!
Fruits, vegetables, cereals, and other edible plants are sources of carbohydrates constituting potential prebiotics. According to Wang (2009), there are specific criteria for the classification of food components as prebiotics. One criterion assumes that prebiotics are not digested (or just partially digested) in the upper segments of the gastrointestinal tract. As a consequence, they reach the colon, where they are selectively fermented by potentially beneficial bacteria. The fermentation may lead to the increased production of different SCFAs, increased stool mass, a moderate reduction of colonic pH, reduction of nitrous end products and fecal enzymes, and an improvement of the immunological system. Selective stimulation of growth and activity of the intestinal bacteria potentially associated with health protection and wellbeing is also important. Lastly, a prebiotic must be able to withstand food processing conditions and remained unchanged and available for bacterial metabolism in the intestine.
Fruits, vegetables, cereals, and other edible plants are sources of carbohydrates constituting potential prebiotics.
Probiotics are safe for the majority of the population, but side effects can occur. The most common side effects are a temporary increase in gas, bloating, constipation and thirst. Some people can also react poorly to ingredients used in probiotic supplements. If this occurs, probiotics must be stopped. In rare cases, people with compromised immune systems, prolonged hospitalizations, or recent surgeries may develop an infection from probiotic bacteria. People with these conditions should weigh the risks and benefits before consuming probiotics. In future articles, we will try to look at certain prebiotics and probiotics, and the studies that promote or refute their clinical use.