The human intestinal flora is the vast collection of bacteria and other microorganisms that live symbiotically in the gut. These microorganisms and the metabolites they produce play an important role in influencing human health and immune function.

The immune system is critical for defense against a variety of invading pathogens, including bacteria and viruses. Individuals with weakened immune systems, such as the elderly, are more susceptible to infections, autoimmune diseases and inflammatory diseases. Gut flora imbalance (ecological dysbiosis) is associated with many age-related diseases.

The composition of the intestinal flora changes with age. In addition, diet and exercise play a crucial role in shaping the composition and diversity of the gut microbiota.

Changes in diet and nutritional intake are common in older adults due to changes in appetite, digestive capacity, food sensitivity or access to proper nutrition. Studies have shown that older adults consume less than recommended amounts of vitamins and minerals, which are critical for anti-inflammatory responses and immune regulation. Decreased protein intake has also been noted in older adults, leading to various health complications, such as a decrease in lean body mass.

In older adults, altered dietary patterns lead to dysbiosis of the gut microbiota, characterized by a decrease in microbial diversity and butyrate-producing microbes and an increase in parthenogenic anaerobic microbes. Together, these changes lead to the development of a chronic, low-grade inflammatory state, which is a hallmark of many age-related diseases.

Several studies have been conducted to identify dietary interventions that can improve the structure and function of the gut microbiota in older adults. Several probiotics have been found to increase the growth of beneficial flora and decrease the growth of opportunistic bacteria in older adults. Similarly, prebiotic galacto-oligosaccharides have been found to restore intestinal flora composition and reduce inflammation in older adults.

As scientists have mentioned, more research is needed to understand the extent to which dietary patterns affect the structure and function of the gut microbiota in older adults. Well-controlled trials are also needed to identify effective dietary interventions to improve the overall health of older adults by modulating the intestinal microbiota.