The composition of human gut microbiota changes with age, and the most drastic change happens 2-3 years post-birth and then a steady-state arrives as we transit into adulthood. At older ages, the decline in human physiological functions leads to a decrease in the number of these beneficial microorganisms in the intestinal microflora and consequently, the occurrence of various intestinal diseases.
A plant-based diet and eating prebiotics/probiotics supplements may increase the number of intestinal probiotics, thereby preventing intestinal diseases. However, the connection among diet, microorganisms, and host has not been fully elucidated. Genome-scale metabolism models can help clarify their relationship, deepen the understanding of intestinal microbial metabolism, and predict the metabolic changes of the intestinal microflora during aging, so as to screen out better probiotics/prebiotics.
Gut microbiota of healthy young people
Microbiology's non-cultivation technology testing shows a large gap in the intestinal microflora between individuals caused by many factors such as diet, geography, health care level, host genetic characteristics, and early microbial exposure. It is also affected by birth method, antibiotic application, feeding type, hospital environment, and the type of probiotics/prebiotics. Vaginal delivery and breastfeeding are considered to be the best options for maintaining a healthy gut microflora for the newborn.
Gut microbiota in healthy aging
A diet rich in fiber is conducive to the balance of intestinal microbes. As the content of Firmicutes in the intestinal flora of the elderly decreases, the overall flora diversity also declines. The change of intestinal microbiota during the aging process provides a favorable environment for the growth of intestinal pathogens.
According to some studies, the gut microbiota in the elderly with C. difficile infection showed a higher diversity of Lactobacillus and Clostridium, and a lower diversity of Bacteroides, Prevotella, and Bifidobacterium.
The influence of gut microbiota on the human body as we age
As the human body ages, the content of Gram-negative bacteria and other pathogens in the intestinal microflora increases. The level of short-chain fatty acids (SCFAs), especially acetate, butyrate, and propionate, has decreased, adversely affecting human health. Gram-negative bacteria can secrete lipopolysaccharide, which may be an endotoxin. Lipopolysaccharide is a carbohydrate-fat complex that can cause intestinal inflammation. Butyrate can improve the anti-inflammatory activity of the immune system. Butyrate-mediated epigenetic modification in immune cells (such as macrophages) can reduce the secretion of inflammatory factors such as IL-6. Some studies have proved the anti-inflammatory activity of acetate and propionate.
More research is still needed to fill the knowledge gap between the age-related changes in gut microbial ecology and human health and reveal more specific interventions to treat or delay intestinal-related diseases in the elderly.
At present, combining 16S rRNA high-throughput sequencing with various omics technologies has greatly promoted the rapid development of intestinal microbial research. Creative Proteomics can provide you with gut microbiome services, including 16s sequencing, gut metagenomic sequencing, microbial proteomics services, microbial metabolomics services, etc.