
In a review article published within the journal Frontiers in Sports and Energetic Living, scientists discussed the impact of eating regimen and exercise on gut microbiota composition, diversity, and functions in older adults.
Study: Growing old together: What we all know in regards to the influence of eating regimen and exercise on the aging host’s gut microbiome. Image Credit: Christoph Burgstedt / Shutterstock
Background
The human gut microbiota refers to an infinite collection of bacteria and other microorganisms that symbiotically reside contained in the intestinal tract. These microorganisms and the metabolites produced by them collectively play a very important role in influencing human health and immune functioning.
The immune system is significant for defending against various invading pathogens, including bacteria and viruses. Individuals with a weakened immune system, reminiscent of older people, are more vulnerable to infections and autoimmune and inflammatory diseases. An imbalance in gut microbiota (dysbiosis) is related to many age-related diseases.
It’s well-documented within the literature that gut microbiota composition changes with increasing age. Furthermore, eating regimen and exercise play an important role in shaping gut microbiota composition and variety.
On this review, scientists have analyzed available literature to offer an outline of the impact of eating regimen and exercise on gut microbiota and its functions in older adults.
Impact of eating regimen on aging gut microbiota
Weight-reduction plan is one in every of the primary aspects accountable for regulating gut microbiota composition and variety. Individuals residing in several geographical locations exhibit significant variations in gut microbiota structure due to differences of their dietary habits.
A lack of microbial diversity has been observed amongst residents of non-western countries who’ve migrated to america. Similarly, diets enriched with food emulsifiers are known to vary the gut microbiota composition, which subsequently induces low-grade inflammation.
Dietary macro- and micronutrients are digested within the gastrointestinal (GI) tract, and the metabolites are absorbed through the intestinal mucosa into the bloodstream. The gut microbiota plays an important role in regulating digestion and absorption of dietary compounds. Evidence indicates that diets lacking healthy nutrients can induce various health adversities by changing gut microbiota composition. While fiber-rich and low-calorie diets are known to extend longevity, consumption of high-fat and low-fiber diets has been found to associate with reduced longevity.
Western diets with low fiber content and high fat, sugar, and salt content can significantly increase endotoxin-releasing bacteria, which in turn can induce immune responses through pathogen-associated molecular patterns. In contrast, the Mediterranean eating regimen that incorporates high amounts of vegetables, fruits, nuts, fibers, olive oil, and red wine can increase bacterial community that produces useful metabolites, including short-chain fatty acids (SCFAs).
An alteration in eating regimen and nutrient intake is often observed amongst older adults due to changes in appetite, digestion ability, food sensitivity, or access to proper nutrition. Studies have shown that older adults devour lower than really useful amounts of vitamins and minerals vital for anti-inflammatory responses and immune regulation. A discount in protein consumption has also been noticed in older adults, leading to varied health complications, reminiscent of lack of lean body mass.
In older adults, changes in dietary patterns induce gut microbiota dysbiosis, characterised by reduced microbial diversity and butyrate-producing microbes and increased facultative anaerobic microbes. These changes collectively result in the event of a chronic, low-grade inflammatory state, which is the hallmark of many age-related diseases.
Some studies have been done to discover dietary interventions that may improve gut microbiota structure and performance in older adults. Some probiotics have been found to extend the expansion of useful bacterial populations and reduce the expansion of opportunistic bacteria in older adults. Similarly, prebiotic galacto-oligosaccharides have been found to revive gut microbiota composition and reduce inflammation in older adults.
As mentioned by the scientists, more studies are needed to know the extent to which dietary patterns can influence gut microbiota structure and performance in older adults. Well-controlled trials are also needed to discover effective dietary interventions that may improve the general health of aging populations by modulating gut microbiota.
Impact of exercise on aging gut microbiota
Regular physical activity improves cardiorespiratory fitness and overall health by reducing the chance of chronic diseases (cardiovascular and metabolic diseases) and all-cause mortality. In older adults, inflammation and immune senescence are the numerous determinants of assorted diseases related to high mortality rates. Regular exercise can significantly reduce the chance of those diseases by reducing chronic, low-grade inflammation, improving immune functions, and increasing autophagy (a cellular process to degrade and take away cellular debris).
There may be evidence showing that regular exercise influences gut microbiota composition and variety. Nevertheless, due to a scarcity of control for eating regimen and age and exercise training regimen, these studies couldn’t conclusively determine the mechanisms and the extent to which exercise influences gut microbiota.
On this context, one well-controlled animal study has shown that six weeks of voluntary wheel running reduces gut microbiota richness in young mice in comparison with that attributable to forced treadmill running or sedentary conditions. Mice performing forced treadmill running, alternatively, exhibit enrichment of certain endotoxin-producing bacteria which can be related to GI tract pathologies.
The study’s outcomes indicate that exercise could have each useful and detrimental effects on gut microbiota, depending on the sort of stimulus.
Human studies involving skilled rugby athletes have indicated that exercise increases the functional capability of gut microbiota. Furthermore, evidence shows that athletes’ cardiorespiratory fitness level is very correlated with gut microbiota composition and variety. Furthermore, a direct association has been observed between cardiorespiratory fitness level and genes related to SCFA biosynthesis, bacterial chemotaxis, and motility.
Endurance exercise conducted for six weeks has been found to change gut microbiota composition and SCFA levels in young people depending on the body mass index (BMI). Healthy adults undergoing endurance exercise and resistance exercise for 8 weeks have been found to exhibit only minimal changes in gut microbiota composition and performance and no change in microbial diversity.
Based on the findings of those studies, scientists highlight the necessity for more longitudinal studies to know to which extent exercise modulates gut microbiota and the end result of those modifications, especially in elderly populations.