The gut microbiome constitutes bacteria, viruses, yeast, and parasites that reside in the gut. There are an estimated 100 trillion organisms that live in the gut, and more than 1,000 subspecies have been identified to date. Most bacteria in the gut reside in the large intestine and are involved in every aspect of gut function, performing many tasks that are essential to life. The functions of the microbiome are expansive and include assisting with digestion and absorption of foods and nutrients, protecting against pathogenic organisms, regulating and training the immune system, and synthesizing essential vitamins that we are not able to produce.
Functions of The Microbiome
The major functions of the microbiome can be divided into three major parts:
- Protect: against pathogens and overgrowth of potential pathogens by crowding out or displacing noxious organisms.
- Structure: barrier fortification, strengthening of tight junctions between intestinal cells, and development of a healthy immune system capable of appropriately responding to harmful and benign stimuli.
- Metabolism: synthesis of vitamins and fermentation of non-digestible dietary fiber to produce short-chain fatty acids (SCFAs), which are important for nutrition and energy for intestinal cells. SCFAs have also been implicated in ant-inflammatory modulation and satiety signaling.
Microbes in the gut fall into three major categories:
- Symbionts represent different organisms that live together. Microbes are sub-divided into mutualistic (both organisms benefit), commensals (one benefits, the other is unaffected), and parasitic (one benefits, the other is harmed). Most of the gut microbiome is composed of commensal or ‘friendly’ organisms that provide balance in gut ecology.
- Pathobionts represent organisms that have the capability to cause harm to the host under the right environmental circumstances in which they are allowed to overgrow. An example of a pathobiont is dificile overgrowth and infection in the setting of antibiotic wipeout of commensals. Pathobionts may also be associated with chronic inflammatory conditions.
- Pathogens cause harm to the host and produce disease. These are classical organisms that cause acute infection.
There are four major classifications that constitute the majority of microbes in the gut: bacteroidetes, firmicutes, actinobacteria, and proteobacteria. Ecological shifts in the relative proportion of bacteria in these four categories may be one factor that leads to the initiation of disease. “Dysbiosis” is the scientific term used to describe alterations in the gut microbiome that lead to the start of the disease. Dysbiosis represents an imbalance in the microbial ecosystem that leaves it vulnerable to overgrowth of pathobionts and pathogens, compromise of gut barrier function, inflammation, and changes in metabolic functions.
There are multiple types of dysbiosis:
- Loss of good bacteria
- Loss of microbial diversity
- Shifts in metabolic capacity, usually a result of growing more bad bacteria that harvest excess energy from food
- Blooms of pathogens (yeast overgrowth or parasites)
- Displacement of bacteria from the large to small intestine (small intestinal bacterial overgrowth (SIBO)- Ask Joe about our SIBO Supplement Protocol!)
What can cause/trigger dysbiosis?
- Antibiotics (often the primary culprit)
- Poor nutrition
- Chronic stress
- Alcohol use
- Proton-Pump Inhibitors (PPIs)
- Nonsteroidal Anti-Inflammatory Drugs (NSAIDs)
There is a great focus on the role of our poor lifestyle choices as a trigger for gut dysbiosis, which also affects how we develop immune and metabolic diseases.
Clinically, symptoms of gut dysbiosis vary tremendously from person to person and may include:
- Frequent gas, bloating, belching
- Loose stools, diarrhea, constipation
- Acid reflux
- Unexplained weight gain and/or difficult weight loss
- Irritable bowel syndrome (IBS)
- Irritable bowel disease (IBD)
- Depression and/or frequent low mood
- Halitosis (chronic bad breath)
- Brain fog
- Joint pain
- Skin conditions (acne, eczema, psoriasis)
- Low energy and chronic fatigue
- Diagnosis of an autoimmune condition (like Hashimoto’s or RA)
- Allergies and food sensitivities
- Chronic yeast or fungal infections
Joe uses a functional medicine approach to diagnose dysbiosis with our patients who come in for Nutrition Response Testing, one of the protocols we use to determine your risk for gut dysbiosis. There is no “gold standard” test, and multiple testing styles may be used to establish the health of the gut microbiome.
If you would like to learn more or schedule a visit with Joe to discuss your health needs and care, click here to schedule online, or text us at (203) 257-7550!