The gastrointestinal tract is an ecosystem, with a balance between aerobic (“oxygen loving”) and anaerobic (“oxygen hating”) microorganisms. This complex microbial ecosystem is packed with over 100 trillion microbes. Each person usually hosts around 160 different microbial species (called the gut flora) that promote normal gastrointestinal function, provide protections from infection, produce needed vitamins, breakdown toxins, modulate immune responses, and balance systemic metabolism.
Probiotics are either member species of the essential intestinal microbiota or they are transient species affecting the gut as they pass through the gastrointestinal tract. The majority of bacteria are located in the colon. In a healthy gut the dominant flora is composed of beneficial bacteria of the Lactobacillus and Bifidobacteria species.
A healthy gut flora/microbiota is essential for the normal development of the GI system and immune systems. The microbiome guides the immunologic maturation and modulates immune function throughout life.
Dysbiosis is the overgrowth of harmful bacteria that cause disease and dysfunction. It can exist in the oral cavity, the GI system or vaginal cavity. In gastrointestinal dysbiosis, organisms such as yeast, bacteria and parasites induce disease/dysfunction in the following ways:
• They inhibit normal bacteria, creating deficiencies in nutrients and other problems;
• They cause inflammation in the digestive system compromising absorption and contributing to deficiencies of nutrients, protein, carbohydrates and fats;
• They produce toxins. Harmful bacteria create toxins and inhibit normal bacteria from detoxifying the bowel. Toxins can burden the liver and the body’s detoxification system, affecting every function in the body;
• They lower the levels of short chain fatty acids, thus increasing the risk of colon cancer and ulcerative colitis;
• They hydrogenate polyunsaturated fatty acids; and
• They irritate the lining of the intestine, increasing intestinal permeability (leaky gut).
Some common causes of dysbiosis include:
• Antibiotic therapy;
• Presence of xenobiotics such as chemicals and heavy metals;
• Exposure to pathogens/parasitic infections;
• Pancreatic insufficiency;
• Slow bowel transit time/bowel stasis;
• Poor immune function and low intestinal secretory IgA;
• Nutrient deficiencies;
• A fiber deficient diet; and
• Increased intestinal pH.
Dysbiosis has been associated with the following disease and disorders:
• Chronic gastrointestinal problems eg. irritable bowel syndrome or inflammatory bowel disease;
• Inflammatory or autoimmune disorders such as ankylosing spondylitis, fibromyalgia and arthritis;
• Food allergy and intolerance;
• Breast and colon cancer;
• Unexplained fatigue;
• Atopic eczema;
• Pancreatic insufficiency;
• Intestinal hyperpermeability; and
There is a close connection between the brain and gut. We speak of “gut feelings” and “gut instinct”. Courage means to “have guts”. Anxiety is “butterflies in the stomach”. Current research reveals that most of the communication along the brain-gut axis is from the gastrointestinal system to the central nervous system (CNS)/brain and that the gut activities can modulate or effect emotions, desires and mood!
Evidence is now accumulating that the gut microbiota is necessary for normal CNS maturation and impact neural circuits controlling motor function and anxiety behaviour. The brain-gut axis is now seen as including the gut microbiota in the new paradigm of the brain-gut-microbiome axis. Probiotics were first proposed as an adjunctive therapy for major depression in 2005. Since that time data from many clinical studies support the use of probiotics in the management of affective/mood disorders and other neurological conditions.
Friendly and beneficial bacteria play a crucial role with health. Supplementation with the appropriate strains of bacteria re-establishes a healthy intestinal terrain, maintains appropriate bowel transit time and offers assistance in cases of GI distress. It is part of a healing strategy, especially for constipation/diarrhea, dysbiosis, IBS, infection, mood issues, neurological issues and during and following antibiotic treatment.