Gut Microbiota and the Brain – part 1
Researchers are now beginning to understand the ways in which bacteria living in the human gut—the gut microbiota—communicate with and influence brain health. The concept of a faulty “gut/brain axis” has been associated with various neurologic and psychiatric outcomes and is thought to be explained, at least in part, by immune dysfunction and inflammation triggered by poor gut health.
Recently, the gut microbiota has emerged as an important focus in the understanding of noncommunicable diseases, including type 2 diabetes and cardiovascular disease, as well as disorders of the brain. When I say, “recently”, I mean that the research is finally catching up with what we, and other like-minded natural doctors have been saying for an awefully long time. As the baby-boomer generation is aging, brain-related conditions are placing a noticable burden on society, and the limitations of current medical treatment reflects the need for an alternative view.
Biome and Brain Overview
Our human intestinal microbiome is seeded at birth; it is influenced initially by delivery and maternal feeding, and reaches an adult-like state within the first few years of life. Alterations in this essential micro-environment have been linked to a broad range of diseases, including autoimmune diseases, metabolic disorders, gastrointestinal issues, and brain disorders both in childhood and later life.
The composition of the individual’s gut microbiota is greatly influenced by factors as geography, food choices, OTC and prescription drug use, antibiotic intake, exercise, stress, and even one’s belief system. Failure to evaluate and address the gut and its enviroment may be the number one reason conventional medicine fails in treating chronic conditions.
Research is now proving that bidirectional gut/brain communication may occur directly and indirectly via the central and enteric nervous systems, the vagus nerve (CN X), and the endocrine and immunoinflammatory systems and through the modulation of neurotransmitters. Where once standard MDs laughed at us ‘natural doctors’ for suggesting that diet and gut health influenced everything from autoimmune disease to brain health, it now is indisputable. I must confess that even this past week a patient commented that their oncologist told them that diet had, “nothing to do with cancer,” so ignorance still prevails.
From a testing perspective, there is no current “gold standard” healthy intestinal microbial profile. New testing protocols coming out of Japan are proving to be exciting but it is not yet available in the US. In general, a diverse gut microbiota promotes gut health and maintains essential structural, metabolic and signaling functions. I am suggesting that the human gut can be “unhealthy” for a variety of reasons that cause a shift away from the diversity and stability. This “dysbiosis” means that the individual has lost his/her ability to sustain one or more of the functions of a healthy gut, and this may contribute to disease.
Increased intestinal permeability, often called “leaky gut,” occurs when the mucosal gut barrier fails to prevent potentially harmful molecules from entering the bloodstream; these molecules include lipopolysaccharides, which are found on the outer membrane of gram-negative bacteria and may elicit inflammatory responses in the body. However, increased permiability is of greater concern when one understands that it is not just pathological leakage past gut barriers that cause problems. Peptides of partially digested proteins that were never supposed to be absorbed cross damaged intestinal walls and become immune antigens that wreak havoc on endothelial cells (leading to CVD) and tissue cells alike. I purpose that increased intestinal permeability is a root cause of most chronic disorders, not just an unhealthy gut.