Nutrition Considerations for Microbiota Health in Diabetes
Recently, it has become accepted that the tiny microbial cells harbored by the human gut play a significant role in health and in certain disease states, including obesity, diabetes, and cardiovascular disease. Although many details remain unclear, new technologies have uncovered many of the physiological benefits the human microbiota provides the host. A healthy gut microbiota plays a role in health, but imbalances can become pathological, increasing inflammation and contributing to metabolic dysfunction. Diet plays a significant role in shaping the composition and function of the microbiota. Eating patterns high in fruits, vegetables, whole grains, and legumes promote the abundance of healthier bacteria that produce short-chain fatty acids and other health-promoting metabolites. This article reviews the functions of the microbiota, how it is formed, and nutritional strategies to improve gut health.
Functions of the Microbiota
The human body harbors >100 trillion organisms; these are mostly bacteria, but also include archaea, viruses, parasites, and fungi, which together make up the microbiota (1,2). In the human body, these tiny microbial cells outnumber human cells by 10 to 1 (2–5). The microbiome, which is the collective genome of the microbiota community living in our gut, outnumbers the human genome by 100- to 200-fold (2–5).
New nonculture-dependent technologies have led to the identification of 1,000 species and >3 million microbial genes, providing evidence of the symbiotic relationship this “organ” has with the human host (1,2,4). Known functions of the microbiota include degradation of nondigestible polysaccharides, synthesis of vitamins, strengthening of the microvilli, and protection of the host from pathogens by maintaining healthy gut barrier integrity (3,5–7). The gut microbiota is instrumental in the normal development of innate and adaptive immunity (4).
Factors Shaping the Composition of the Microbiota
The composition of the human gut microbiota is highly individualized, with …