Probiotics and Gut Health

The human gut microbiome is composed of an enormous number of microorganisms, generally regarded as commensal bacteria. Without this inherent microbial community, we would be unable to digest plant polysaccharides and would have trouble extracting lipids from our diet. Resident gut bacteria are an important contributor to healthy metabolism and there is significant evidence linking gut microbiota and metabolic disorders such as obesity and diabetes. In the past few years, neuroscience research has demonstrated the importance of microbiota in the development of brain systems that are vital to both stress reactivity and stress-related behaviors.

Every living human experiences stress. Stress is a natural response to stimuli that may challenge the body’s homeostatic state. In the realm of biology, stress refers to what happens when an organism responds any unbalance in homeostasis. Understanding the biochemical interactions that constitute the stress response requires a definition of stress. Some stress, of course, can be beneficial. Stress can be brief and beneficial, or it can be long-lasting and harmful, causing depression and paralysis. Often, however, stress can reach chronic, harmful levels, and toxic consequences follow, from compromised immune function to weight gain to developmental impairment. Chronic stress affects the human body in various ways including, but not limited to, the death of brain cells, premature aging, depression, anxiety, severe disruption in the digestive system and changes in menstrual cycles for females. Proper stress management takes on great importance given the wide range of bodily systems impacted by stress hormones. Hormones and neurotransmitters released during stress are believed to be responsible for behavioral changes associated with stress exposure including effects on learning and memory. Research shows it is now clear that gut microbes have an effect on inflammation, pain, eating behaviors, food cravings, mood and other seemingly unrelated symptoms, such as depression or uncontrolled anxiety.  In addition, it is common for depression and anxiety to co-exist with disorders such as IBS (irritable bowel disorder).
The gut-brain axis provides a way of communicating both directions using signals, such as neurotransmitters, hormones and cytokines. There is proven research that microbial balance and imbalance influences emotions and immunity health.  Equally important the emotions one may feel and neurotransmitters produced by the brain have a profound effect on the gut as well. Dysfunction in the communication between gut and brain can lead to various diseases, including depression and anxiety.  The human gut is populated by more than 100 trillion microbes. As humans are exposed to stress, chemicals, antibiotics, and toxins, the diversity of the microbiome decreases, there is more susceptibility to illness and disease. Gut microbitia functions include:
●               Development of immune system function
●               Assisting with bowel movements and gut motility
●               Maintaining intestinal cell barrier integrity
●               Aiding in digestion and absorption of specific vitamins and minerals
●               Controlling fat absorption and distribution

Microbes and Stress

What is increasingly clear is that there is bi-directional communication between gut microbes influencing the central nervous system and brain and the reverse; communication between the brain influencing microbial composition.   

These are the top 3 ways that chronic stress affects the gut:

1.              Increases the levels of inflammatory cytokines (IL-6, TNF-alpha) which can changes gut microbe populations.

2.              Increases permeability of the gut lining, which is linked to many autoimmune diseases  (Hashimoto’s thyroiditis, lupus, rheumatoid arthritis, multiple sclerosis and many others).

3.              Allows bacteria to cross over into the bloodstream where the bacterial coating (LPS) can trigger an intense inflammatory response in the body

The bottom line is there is a growing body of evidence that suggests gut microbes play a large role in regulation in behavior and brain chemistry and are relevant to development of depression and anxiety. Probiotics are now a key to protecting the gut bacteria and aiding in growing new, beneficial cells!