By vegan naturopath Robyn Chuter
As I see more and more clients with complex, chronic health conditions, I am frequently reminded of Hippocrates’ statement from over 2000 years ago:
All disease begins in the gut.
Now, like a lot of pithy sayings, there will always be some exceptions to the rule, but as researchers delve into the inner workings of the digestive tract, more and more health conditions are turning out to have a significant gut component.
And as Dr Corey Howard explained in his presentation at the 2015 International Plant-Based Nutrition Healthcare Conference, that gut component of disease doesn’t just involve our own, human cells. Here are some startling facts to ponder:
- Our bodies are comprised of around 37 trillion cells (in numerals, that’s 37 000 000 000 000).
- The human genome contains approximately 21 000 genes.
- 1.5% of those genes, or around 300 of them, code for proteins (that is, they contain the instructions for making particular proteins).
- The remaining 20 700 genes regulate the expression of the 300 that code for proteins.
- 100 trillion bacteria (that’s 100 000 000 000 000) reside in and on the human body – on our skin, in our nose, ears, lungs, eyeballs, the vagina in females, and of course in our gut.
- There are more than 9 million unique genes in the human gut bacterial community, or over 400 times the number of human genes.
If you’re feeling a little creeped out by the discovery that you are more ‘bug’ than human, you’re not alone. We have been conditioned to think of bacteria as our mortal enemies, to be eradicated by any means necessary. Think of those advertisements you’ve seen for mouthwashes, kitchen sprays and toilet cleaners that proudly trumpet the claim that they ‘kill 99% of bacteria’. The market for antibacterial hand sanitisers has exploded in recent years, and many parents will beg their GP for an antibiotic if they even suspect that their child has a middle ear infection.
But as researchers delve deeper into the human microbiome and how it affects our physical and mental health, it’s becoming more and more clear that attempting to eradicate bacteria from our bodies and living environments is a Very Bad Idea.
Dr Howard focused his presentation on the gut microbiome, although the composition and function of bacteria that live on and in other parts of our bodies is a fascinating subject in itself.
The probiotic or ‘good bacteria’ that inhabit our intestines carry out several vital functions for us. They:
- Produce some vitamins, including vitamin K and biotin, which we can absorb and utilise;
- Synthesise amino acids – the building blocks of protein, which we can also absorb and utilise to build our own body proteins;
- Carry out biotransformation of bile acids – metabolic waste products that contribute to bowel cancer and gallstones – so that they can be safely removed from the body;
- Produce short chain fatty acids including butyrate, which decreases intestinal inflammation, heals ‘leaky gut’, modulates the sensitivity of visceral organs and improves intestinal motility (helping to overcome IBS), protects against colorectal cancer, lowers cholesterol and reduces insulin resistance… among many other benefits;
- Secrete antimicrobial substances which inhibit the growth of ‘bad’ bacteria that can cause intestinal infections, leaky gut and inflammatory conditions including cardiovascular and autoimmune disease.
- Interact with toll-like receptors, helping the immune system to identify and destroy harmful bacteria while tolerating beneficial bacteria, human cells and normal components of food.
- Interact with dendritic cells, a type of immune cell, helping to calm them and reduce their production of inflammatory chemicals.
That’s the good news. The bad news is that the delicate balance of the gut microbiome can be thrown out by a host of factors, setting the stage for all manner of ill-health.
- Babies born by caesarean section are not colonised by the healthy bacteria that a vaginally-delivered baby will encounter on its way through the birth canal. Instead of its mother’s flora, the c-section baby’s gut ends up being populated by bacteria from the air in the operating theatre, and the garments of the doctors and nurses.
- Breast-fed babies receive probiotic bacteria in their mother’s milk, as well as prebiotic oligosaccharides (carbohydrates that can’t be digested by humans, but feed the gut bacteria instead); while formula-fed babies miss out on both.
- Antibiotics, whether prescribed for infectious illnesses (most of which are not life-threatening and would resolve spontaneously if left untreated), or consumed in dairy products, eggs and meat from factory-farmed land and marine animals that are routinely fed antibiotics, dramatically reduce the diversity of the gut microbiome and can set the stage for colonisation by pathogens such as Clostridium difficule.
- A wide range of other drugs, including proton pump inhibitors (acid suppressors such as Losec and Nexium); non-steroidal anti-inflammatories and oral contraceptives, decrease the number of beneficial bacteria inhabiting the gut.
As Dr Howard explained, if you have acquired imbalances in your gut microbiome that are contributing to digestive discomfort and poor health, just taking probiotics won’t get you well again. You’ll need a total dietary overhaul to remove the substances that derange your microbial colonies (artificial sweeteners, animal products laced with antibiotics, refined carbohydrates) and add in the substances that restore balance (fibre, resistant starch, fermented foods); you need to get off drugs that wreak havoc on your gut flora; quit smoking and excessive drinking; and get regular exercise.
Does all of this sound familiar? The same lifestyle measures which promote the health of your human cells also promote the health of your microbiome… and perhaps that is no coincidence.