Gut Microbiome and Probiotics

Probiotics are live micro-organisms in your gut that benefit health – called the gut microbiota, flora, or microbiome. Approximately 100 trillion micro-organisms (mostly bacteria, but also viruses, fungi, and protozoa) exist in our gastrointestinal tracts. Most of the gut flora is found in your colon, or large intestine. The metabolic activities of gut flora resemble those of an organ.

The microbiome consists of microbes that are both helpful and potentially harmful. Most are symbiotic (where both the human body and microbiota benefit) and some, in smaller numbers, are pathogenic (promoting disease). In a healthy body, pathogenic and symbiotic microbiota co-exist without problems. If there is a disturbance in microbiota balance - brought on by infectious illnesses, certain diets, or the prolonged use of

antibiotics or other bacteria-destroying medications - dysbiosis occurs.

Lipopolysaccharides (LPS) are bacterial toxins (part of E. coli and Salmonella) that can cause inflammation if they travel from the gut to the bloodstream. This generally occurs if you have an infection, “leaky gut”, or eat too many fatty foods.

Gut microbiome functions include:

1/ Metabolism > synthesize certain vitamins and amino acids, including the B vitamins and vitamin K (eg. the key enzymes needed to form vitamin B12 are only found in bacteria). > certain bacteria use enzymes to digest complex carbohydrates, producing short-chain fatty acids (SCFAs) which: [a] provide energy, oxygen and nutrients for bacterial growth and proliferation

[b] help ulcerative colitis, Crohn’s disease, and antibiotic-associated diarrhoea.

[c] stimulate your immune system

[d] strengthen your gut wall => prevent unwanted substances entering your bloodstream.

[e] regulate blood glucose and cholesterol levels

[f] improve satiety

2/ Host Protection and Immune-system Development >Intestinal bacteria [a] produce anti-microbial compounds and [b]compete for nutrients and sites of attachment in the gut lining => thereby preventing colonization by pathogens. >The cells of the intestinal lining signal the immune system, leading to the host’s immune response and release of protective cells. The result can be [a] a protective response to good bacteria, [b] an inflammatory response to pathogenic organisms, or [c] a trigger for a host’s cell death (anti-cancer). >The microbiome is also implicated in allergy prevention (ie, a disproportionate reaction of the immune system to non-harmful antigens). 3/ The Gut–Brain Axis >This communication system uses nerves, hormones and immune cells to signal between the gut and the brain. >Stress influences the gut microbiota’s composition and the bi-directional communication between the gut and the central nervous system influences a host’s stress response. >Stress reduces the integrity of the gut lining and alters peristalsis, secretions, and mucin production, thereby altering the intestinal microbiota’s habitat and promoting changes in microbial composition and/or metabolism.

How to Develop a Healthy Gut Microbiome Diet, genes, environment, and medication use create your unique microbiome. The gut microbiota evolves throughout life and plays a pivotal role in both health and disease. As you grow, your gut microbiome begins to diversify. Higher microbiome diversity is considered good for your health. 1/ Vaginal birth (if possible) - first exposure to microbes is passing through the birth canal. 2/ Breastfeed for at least six months to increase beneficial Bifidobacteria. 3/ The food you eat affects the diversity of your gut bacteria. Your gut flora is highly sensitive to diet, and an unbalanced gut flora is linked to numerous diseases including obesity, type 2 diabetes, metabolic syndrome, heart disease, colorectal cancer, Alzheimer’s, and depression.​

• Eat a diverse range of foods (legumes, beans and fruit) => diverse microbiome.

• Probiotics prevent the overgrowth of ‘bad’ bacteria by competing for nutrients & attachment sites. Probiotic foods are fermented and contain 'good' bacteria – yogurt, kefir, sauerkraut, and kimchi.

• Prebiotics are indigestible carbohydrates and fibres such as inulin that feed the good bacteria - raw garlic, onions, leeks, asparagus, dandelion greens, apples and bananas,

• Whole grains (wheat, oats, barley) contain fibre and beneficial carbs which are digested by gut flora.

• Limit artificial sweeteners - aspartame increases blood sugar by stimulating the growth of unhealthy bacteria.

• Plant-based diet - reduces levels of disease-causing bacteria such as E. coli.

• Eat foods rich in polyphenols (plant compounds) - broken down by the microbiome to increase growth of good bacteria - found in red wine, green tea, dark chocolate, olive oil and whole grains.

• Take antibiotics only when necessary - they kill both bad and good bacteria!

• Take a probiotic supplement - to restore the gut to a healthy state after dysbiosis.

Probiotic Supplements Supplements can be a very effective and inexpensive method of improving your gut health. Products that contain both prebiotics and probiotics are referred to as synbiotics. Synbiotic products usually combine friendly bacteria along with some food for the bacteria to eat (the prebiotics). The most common probiotic bacteria are Lactobacillus and Bifidobacteria. Other common kinds are Saccharomyces, Streptococcus, Enterococcus, Escherichia, and Bacillus.

Probiotic Supplements can: 1. restore the natural balance of gut bacteria. An imbalance means there are too many bad & not enough good bacteria. It can happen due to illness, medication (eg. antibiotics) or poor diet. Consequences include digestive issues, allergies, mental health problems and obesity. 2. help prevent travellers’ diarrhoea and treat diarrhoea (due to infection or medication) 3. help reduce symptoms of ulcerative colitis and IBS, 4. improve gut issues such as bloating, gas, flatulence and stomach cramps. 5. reduce the severity of allergies and eczema. 6. reduce number and duration of infections (> 70% of your immune system is in your gut!). 7. improve anxiety, depression, autism, OCD and memory. 8. promotes brain health - bad bacteria can send confusing signals via your spinal cord, leading to stress, brain fog or memory lapses. 9. lower “bad” cholesterol and blood pressure. Certain lactic acid-producing bacteria may reduce cholesterol by breaking down bile and preventing reabsorption as cholesterol. 10. prevent the absorption of dietary fat in the intestine. The fat is then excreted. 11. reduce systemic inflammation, a leading driver of many diseases. 12. increase the ability of cells to replicate themselves => possibly extend lifespan. What To Look For in Supplements? > 8-10 strains of Bifidobacterium + Lactobacillus – 2 very effective probiotic species. > 25-30B CFU - ensure that your probiotic delivers sufficient CFU (colony forming units). > includes around 75 to 100mg of prebiotic inulin (food for the good bacteria). (adapted from: www.healthline.com; clinical-reviews.com; www.bmj.com)