Your Gut Microbiota Holds The Key To Better Health, Part 1

Gut Microbiota is a complex ecosystem of microorganisms, including bacteria, viruses, fungi, and parasites, that inhabit the human intestinal tract. The number of microbes in the human body is estimated to be around 39 trillion, slightly exceeding the number of human cells. However, their genetic material is much richer and has a profound impact on bodily functions.

The microbiota performs many key functions, such as aiding digestion, synthesizing vitamins, protecting against pathogens, and supporting the immune system. A healthy microbiota is key to maintaining long-term health, whereas imbalances may trigger a wide range of diseases.

How does the microbiota affect our body?

The microbiota’s impact on metabolism

Gut microbiota plays a crucial role in regulating metabolism, maintaining a healthy weight, and preventing metabolic disorders. Its imbalance can lead to obesity, insulin resistance, and chronic inflammation.

• Weight regulation: Akkermansia muciniphila and Faecalibacterium prausnitzii are associated with healthy metabolism and obesity prevention. Dysbiosis may lead to increased calorie absorption and insulin resistance, contributing to weight gain.
• SCFA production (short-chain fatty acids): Microbiota ferments dietary fibers to produce butyrate, acetate, and propionate, which improve insulin sensitivity, reduce inflammation, and support gut barrier health.

Hormonal balance and gut microbiota

Gut microbiota affects hormonal balance by regulating estrogen metabolism and stress hormone levels. Microbiota imbalances may worsen hormonal dysregulation and promote inflammation.

• Estrogen: Microbiota regulates estrogen levels, including estrogen dominance, potentially affecting risks of endometriosis, PCOS, and breast cancer.
• Cortisol: Stress and microbiota imbalance influence the hypothalamic-pituitary-adrenal axis, increasing chronic stress and weakening immune function.

Supporting body barriers

Gut microbiota plays a vital role in maintaining the body’s protective barriers, including mucous membranes and skin.

• Gut barrier: Microbiota helps preserve intestinal integrity and prevents pathogen infiltration. Damage to this barrier, known as “leaky gut,” is linked to systemic inflammation, autoimmune diseases, and allergies.
• Skin barrier: Microbiota imbalances may affect skin conditions such as acne, eczema, psoriasis, or rosacea.

Detoxification and toxin defense

Gut microbiota supports detoxification by metabolizing toxins and producing protective substances.

• Toxin metabolism: Gut bacteria help neutralize toxins, reducing the liver’s load.
• Bioactive compounds: Microbiota converts food into beneficial metabolites, promoting cell health and reducing inflammation.

Cardiovascular system impact

Microbiota influences cardiovascular health by regulating inflammation and metabolism.

• Trimethylamine-N-oxide (TMAO): A microbial metabolite that may increase cardiovascular disease risk.
• Reducing inflammation: SCFAs produced by microbiota help lower inflammation and promote heart health, reducing risks of atherosclerosis, hypertension, and other cardiovascular diseases.

Energy metabolism

Gut microbiota contributes to efficient energy metabolism, which is essential for energy levels and fatigue prevention.

• Nutrient absorption: Microbiota aids in nutrient digestion, improving energy availability and preventing chronic fatigue.

Emotional health and the gut-brain axis

Microbiota plays a significant role in mood and cognition regulation via neurotransmitters and neuroinflammation.

• Neurotransmitter production: Microbiota helps synthesize serotonin (up to 90% produced in the gut), GABA, dopamine, and other neurotransmitters affecting mood and cognition. Microbiota changes are linked to depression, anxiety, autism, and dementia.
• Neuroinflammation: Dysbiosis may promote brain inflammation, affecting memory and mood.

Gut microbiota and fertility

Normal microbiota function is critical for reproductive health by supporting fat absorption and hormone synthesis.

• Sex hormone synthesis: Fats are needed for hormone production; their poor absorption can lower fertility. Thus, gut absorption is key for fertility.
• Fat-soluble vitamin absorption: Microbiota assists in absorbing or producing fat-soluble vitamins (A, D, E, K) vital for reproductive health:
  • Vitamin A: Regulates egg maturation and reproductive tissue health.
  • Vitamin D: Supports normal ovarian function and sperm quality.
  • Vitamin E: Protects reproductive cells from oxidative stress.
  • Vitamin K: Ensures proper blood flow, crucial for embryo implantation.

What is dysbiosis?

Dysbiosis is a condition involving an imbalance between beneficial (“good”) and harmful (“bad”) microorganisms in the gut, also known as microbiota imbalance. In a healthy state, the microbiota is composed of diverse bacteria that work together to support the body’s functions. However, various factors such as poor diet, antibiotic use, stress, and chronic illness can disrupt this balance. These changes can lead to numerous health problems:

• Overgrowth of pathogenic microorganisms: An increase in harmful microbes promotes their survival and proliferation.
• Formation of pathogenic biofilms: Pathogens create protective biofilms that shield them from immune response and antimicrobial therapy.
• Reduction in beneficial bacteria: Leads to a weakened gut barrier and reduced intestinal defenses.
• Leaky gut: Increased permeability of the gut lining allows toxins, allergens, and inflammatory molecules to enter the bloodstream.
• SIBO (Small Intestinal Bacterial Overgrowth): Characterized by bacterial growth in areas where they are usually scarce, leading to bloating, diarrhea, and other digestive issues.

Dysbiosis is associated with a wide range of health conditions, including inflammatory bowel diseases, metabolic disorders, allergies, autoimmune diseases, and even depression.

Types of dysbiosis

It can affect both the large and small intestines, leading to various health problems with overlapping symptoms.

Large intestine dysbiosis

• Bloating: Caused by gas production during fermentation of undigested carbohydrates.
• Abdominal pain: Due to irritation of the intestinal wall from pathogenic overgrowth.
• Constipation or diarrhea: Imbalance in fiber-digesting bacteria may alter stool consistency.

Main causes of large intestine dysbiosis:

• Antibiotics: Destroy both harmful and beneficial bacteria, disrupting the microbiota balance.
• Poor diet: High sugar intake, low fiber, and lack of food variety reduce microbial diversity.
• Stress: Impacts the gut-brain axis, weakening the gut barrier and promoting dysbiosis.
• Chronic illnesses: Conditions like diabetes, celiac disease, or IBD (Crohn’s or ulcerative colitis) affect gut microbiota.
• Medication use: Birth control pills, anti-inflammatory drugs, and steroids can alter microbiota composition.
• Lifestyle factors: Physical inactivity, excessive alcohol, smoking, and exposure to toxins negatively impact the microbiota.
• Aging: Natural shifts in microbiota with age may contribute to dysbiosis.
• Infections: GI infections caused by bacteria, viruses, or parasites can temporarily disrupt microbial balance.

Small intestine dysbiosis (SIBO/SIFO) key features:

• Bloating after meals: Due to fermentation by bacteria that normally reside in the colon but overgrow in the small intestine.
• Malabsorption: Bacterial overgrowth interferes with the absorption of vitamins and minerals.
• Constipation or diarrhea: Microbial imbalance alters stool consistency.

Main causes of small intestine dysbiosis:

• Gut motility issues: Slow transit due to diabetes, hormone shifts, hypothyroidism, nervous system dysfunction, valve abnormalities, aging, chronic constipation, or post-infectious changes.
• Stomach acid/enzyme deficiencies: Low gastric acid and digestive enzyme production.
• Anatomical changes: Post-surgical changes or intestinal obstruction due to adhesions or scarring.
• Immune dysfunction: Immunodeficiency and compromised gut barrier.
• Microbiota disturbances: Antibiotic use, high carbohydrate intake, and existing dysbiosis.
• Hormonal imbalances: Conditions like hypothyroidism, diabetes, and sex hormone fluctuations.
• External factors: Chronic stress, diets high in sugar and processed carbs, and low fiber intake.

To learn more about small intestinal dysbiosis (SIBO), read:

• SIBO: what lies behind the condition mistaken for a disease, part 1
• SIBO: what lies behind the condition mistaken for a disease, part 2

Conclusion

This article reviewed the role of gut microbiota in maintaining human health, its effects on metabolism, hormonal balance, barrier function, detoxification, and cardiovascular system. We also explored how microbiota imbalances (dysbiosis) can lead to various diseases and disorders, including inflammatory, autoimmune, metabolic, and mental health issues.

In the second part of the article, we will discuss diagnostic and treatment methods for dysbiosis, giving readers guidance on how to manage their microbiota for better gut health.