The differences between peoples’ microbiomes is one reason why we each have different susceptibility to different diseases.
Microbial imbalances are thought to contribute to disease through the cross-talk between the microbes, the chemical waste products they produce and our immune cells. When toxic, this drives an inflammatory response.
Dysbiosis is the name given to an imbalance between beneficial and unbeneficial microbes; typically too many “bad” ones and too few “good” ones. Research is currently unravelling which microbes are beneficial, which ones are neutral and which ones are harmful.
Dysbiosis causes bloating, cramps and abdominal pain as the microbes produce gas and other chemicals, which can distend and irritate the gut. Mild, sub-clinical gut disorders are increasingly common these days. Many people are living with tolerable, but uncomfortable, levels of bloating, gas, digestive disorders and irregular bowel movements. They are called functional disorders, like IBS, because the functionis affected but there is no pathology. While not life threatening, such disorders can be frustrating to live with and may be a sign that your microbiome needs some attention. It’s best not to ignore these symptoms for the long term; dealing with them sooner, rather than later, may help prevent more serious conditions developing years down the line.
There is considerable mounting evidence that dysbiosis in the gut is also associated diseases, both inside or outside the gut. Gut conditions like inflammatory bowel disease, ulcerative colitis, coeliac disease, colorectal cancer and non-gut conditions like allergy, asthma, diabetes, cardiovascular disease, obesity, autoimmune conditions and some neurological diseases. As yet, it is currently debated as to whether or not dysbiosis is a cause, or consequence, of a given disease.
Let’s look at some of these.
Weight gain and obesity
Refined carbohydrates and sugar are foods which feed the unfavourable microbes and yeasts, which then grow and multiply in our gut. A fungal overgrowth, like candida, can trigger more sugary food cravings and weight gain.
The unfavourable microbes make toxic compounds, some are called lipopolysaccharides (LPS). The LPS cause irritation and inflammation when they escape the gut and get into the bloodstream. The inflammation leads to insulin resistance, weight gain and type 2 diabetes.
Diabetics commonly lack the beneficial butyrate-producing bacteria. Among other things, these bacteria help to control blood sugar and insulin levels after a meal. Foods that help the butyrate-producing bacteria to multiply are typically high in resistant starch. Resistant starch is high in cooked and cooled rice, potato and pasta, also fibre from vegetables, oats and legumes. So enjoy your cooled “left-overs” straight from the fridge! Supplements high in resistant starch are inulin (please note spelling, that is inulin, not insulin!) and potato starch.
Obese people have been typically found to have a high number of Firmicutes species compared to low numbers of Bacteroidetes species. It is thought that the Firmicutes could be extracting more calories from the food and promoting more fat storage.
Researchers are finding more and more specific species of bacteria associated with certain cancers, for example helicobacter pylori with stomach cancer; Fusobacterium nucleatum and Escherichia coli with colon cancer; Chlamydia with cervical cancer; Clostridium with liver cancer, and other mouth bacteria associated with pancreatic cancer.This doesn’t mean to say that those bacteria are causing the cancer, they may just be taking advantage of the compromised cells. Research is ongoing.
This may mean that we might be able to detect a pro-cancerous environment years before cancer is detectable, by understanding what bacteria belong where and monitoring how they change over time.
As cancer rates are rising, microbial diversity is decreasing. Is there a connection to explore? Researchers have discovered that both people and mice with cancer who had been given antibiotics, tended to have poorer cancer outcomes to immunotherapy.
Diseases such as multiple sclerosis, lupus, Hashimoto’s (low thyroid), coeliac disease and rheumatoid arthritis develop because the immune system is overactive and making autoantibodies against particular groups of body cells.
The reason why the body makes autoantibodies is through the mechanism of mistaken identity. This means that the immune cells attack and kill our own cells that have certain markers on them (a bit like a birthmark or tattoo) that may look like a pathogen.
For example, Hashimoto’s is an autoimmune disorder whereby the body makes autoantibodies against the thyroid gland in the neck. This progressively damages the gland and its ability to function to regulate our energy. Symptoms of low thyroid are chronic tiredness, hair loss, IBS, panic attacks, weight gain and constipation. It’s now easy to get a full set of thyroid tests with an at-home finger-prick blood test that you submit through the post. If you would like a test, it’s quick, cheap and easy, just ask me and I’ll have a test sent out to you,
People with psychological disorders (anxiety, depression, autism, bi-polar, schizophrenia, Parkinson’s and Alzheimer’s) have been shown to host specific species of gut bacteria, which are different to the microbial species of people with no neurological condition.
Researchers have proposed that the “bad” microbes indirectly alter brain function via inflammatory signalling molecules through the nerves that link the gut and the brain (gut-brain axis) and by directly crossing the blood brain barrier.
Specific probiotic strains have produced mixed, but promising results for improving symptoms of conditions such as anxiety, depression and memory. They have been called psychobiotics.
There is a strong connection between gum disease and heart disease. Bacteria in the mouth enter the blood stream via the inflamed gums. Immune cells in the blood then mount an inflammatory response in the arteries. If this goes on for decades, it is believed this inflammation contributes to atherosclerosis and cardiovascular disease.
Trimethylamine N-oxidase (TMAO) is a compound made by the gut bacteria when we specifically eat animal foods – fish, red meat, eggs & dairy. TMAO seems to make our platelets stickier, which increases our risk of clots, leading to heart attacks and strokes.
Lactobacillus may help to reduce cholesterol when taken as a probiotic.
I hope you are enjoying this short series, learning about your microbiome and gut health. If you have any questions, or if you would like to have a private chat about your own health, head over to this page and send me a message and we’ll arrange a time to talk.
Coming up tomorrow, Part 7, all about the latest tests and treatments available. Keep an eye on your inbox!