Highlights:
- The composition of our gut microbiome can adversely change with age and contribute to chronic diseases.
- These changes can potentially be prevented by eating a fiber-rich diet.
- Consuming probiotics (beneficial gut bacteria) and prebiotics (molecules that beneficial bacteria thrive on) can improve the health of older adults.
It is becoming more widely accepted that maintaining a healthy gut microbiome is essential for overall well-being, and this importance increases as we age. The gut microbiome, a complex community of trillions of microorganisms, plays a crucial role in digestion, immune function, and even mental health. As we grow older, changes in diet, lifestyle, and physiology can impact the balance of these microorganisms, leading to potential health issues. However, several strategies can help support and cultivate a healthy gut microbiome throughout the aging process.
Understanding the Gut Microbiome
The gut microbiome consists of bacteria, viruses, fungi, and other microorganisms that inhabit the digestive tract. These microorganisms (primarily bacteria) perform a variety of functions, including:
- Digesting foods we can’t digest and extracting nutrients
- Producing vitamins (such as B vitamins and vitamin K)
- Regulating the immune system
- Protecting against harmful pathogens
A diverse and balanced gut microbiome is associated with better health outcomes, while imbalances (dysbiosis) can contribute to conditions such as irritable bowel syndrome (IBS), inflammatory bowel disease (IBD), obesity, type 2 diabetes, and mental health disorders.
As we age, several factors can influence the composition and diversity of our gut microbiome:
- Dietary Changes: Older adults may consume less fiber and nutrients due to changes in taste, dental issues, or reduced appetite.
- Medications: Increased use of medications, especially antibiotics, can disrupt the balance of gut bacteria.
- Reduced Immune Function: The aging immune system can alter the gut microbiome, leading to increased susceptibility to infections and inflammation.
- Decreased Physical Activity: Reduced physical activity can negatively impact gut health.
Strategies to Cultivate a Healthy Gut Microbiome with Age
1. Prioritize a Fiber-Rich Diet
Dietary fiber is a fuel source for beneficial gut bacteria. Consuming a variety of fiber-rich foods can help maintain a diverse and balanced microbiome. Such foods include the following:
- Fruits and vegetables: Apples, berries, leafy greens, and root vegetables.
- Whole grains: Oats, quinoa, brown rice, and whole wheat products.
- Legumes: Beans, lentils, chickpeas, and peas.
- Nuts and seeds: Almonds, flaxseeds, chia seeds, and walnuts.
The recommended daily intake of dietary fiber is 14 g/kcal in the U.S. As such, if one is consuming 2,000 calories in a day, getting about 28 g of fiber is recommended.
By definition, consuming ultra-processed foods — characterized as rich in energy (calories), fats, sugars, and salt, but deficient in nutrients and dietary fiber — runs counter to a fiber-rich diet. Indeed, ultra-processed foods are associated with gut dysbiosis, cognitive impairment, and psychological stress. Moreover, ultra-processed foods are typically thought to be responsible for increasing the risk of chronic diseases like obesity, type 2 diabetes, cardiovascular disease, and dementia.
The Mediterranean Diet — characterized by the increased intake of vegetables, fruits, legumes, fish, olive oil, and nuts and reduced consumption of red meat, dairy products, and saturated fats — is linked to reduced mortality and reduced risk of multiple chronic diseases. A keystone study showed that adhering to a Mediterranean Diet for 1-year led to improved gut microbiome composition and overall health. Thus, consuming a fiber-rich diet like the Mediterranean Diet and avoiding ultra-processed foods can promote a healthy gut microbiome, potentially leading to a longer life without disease.
2. Incorporate Probiotics and Prebiotics
Probiotics
Probiotics are beneficial bacteria that can help restore and maintain a healthy gut microbiome. By counteracting age-related microbiome changes, supplementing with probiotics and prebiotics may reverse signs of aging. Examples of probiotics include Lactobacillus rhamnosus, which improves the cognition of older adults with cognitive impairment, and Lactobacillus reuteri, which prevents bone loss in older women with low bone mineral density.
Furthermore, in healthy older adults, combining the probiotics Bifidobacterium bifidum and Bifidobacterium longum improves mental flexibility and reduces stress. Additionally, Akkermansia muciniphila probiotic supplementation was shown to reduce the body weight and fat mass of overweight and obese individuals while reducing markers of cardiometabolic aging. This latter study suggests that probiotics can be used to potentially prevent conditions like cardiovascular disease and diabetes.
Prebiotics
Prebiotics are non-digestible molecules (like fiber) that feed beneficial bacteria. Older adults who took the prebiotics inulin and fructooligosaccharides saw a reduction in frailty, especially those who began the study with higher levels of frailty. Frailty is a measure of the overall health of an individual and was assessed using 62 health-related variables. Additionally, older adults who took a prebiotic called digestion-resistant starch exhibited improved glucose and insulin levels.
Probiotics and prebiotics can also be found in food:
- Probiotics: Yogurt, kefir, sauerkraut, kimchi, and other fermented foods.
- Prebiotics: Chicory root, garlic, onions, leeks, asparagus, bananas, and other fiber-rich foods.
A Lifelong Commitment
Maintaining a healthy gut microbiome is a lifelong commitment that becomes increasingly important as we age. In addition to staying active, staying hydrated, and managing stress, prioritizing a fiber-rich diet and incorporating probiotics and prebiotics can support a balanced and diverse gut microbiome. These strategies can help promote overall health, improve digestion, and enhance the immune system, contributing to a healthier and more vibrant life in our later years.
Comments