In this millennium, new science is unfolding, with many exciting discoveries and advancements. Many old beliefs were being overturned into fallacies and myths of passing time. The landing of man on the moon is one good example of an impossible mission that turned into a ‘mission accomplished’ when astronaut Neil Armstrong and his colleagues stepped on that ‘heavenly body’ five decades ago. In the field of biology, similar great disruptive discoveries of recent times are changing our mindset.
We once believed firmly but erroneously that: “All germs are bad and dirty. They invariably cause diseases. Thus, we have been trying to kill all of them.”
These are what we were taught by our respected school teachers of those good old days. And whatever our teachers said then, was generally regarded as gospel truth. Today microbiologists from anywhere across the world would testify that, we were utterly wrong in our long-held notion that, ‘All germs are bad and dirty’.
What laymen refer to as germs are microorganisms such as viruses, bacteria, yeasts, and fungi which are collectively known as microbiomes when they are cohabitating with us. Grouping them together, they comprise 100 trillion cells. In comparison to the total number of cells of all the human organs which number about seven to 10 trillion cells, the true human cells are 10 times less than the number of microorganisms living with us, in or on our body. Thus, our own body cells are literally outnumbered – We are made up of 90 percent microorganisms and 10 percent human cells!
Fortunately, there are far more good germs than bad germs in and on us – an estimated 85 percent of the microbiomes are now known to be good health-enhancing germs. These microbiomes are essential for our survival. Without them in our body, the entire human species would have perished.
Huge numbers of bacteria were well-known to be present in the large caecum of the rabbits, cows, and other herbivores to help them digest the cellulose of the plants they eat. Through the process of evolution, herbivores evolved in stages over millions of years to become omnivorous homo sapiens (humans) where the caecum evolved into an underdeveloped shrunken vestigial leftover structure – a redundant fingerlike projection of our colon called appendix, that often got infected and required surgical removal. Nonetheless, microbiomes are present in large quantities in the human large intestine (colon) to perform multiple useful functions such as the digestion of foods, metabolism of micronutrients, detoxification of toxins and war against harmful disease-causing microbes.
In the year 2000, scientists from 20 institutions in six countries worked together for nearly three years to map out the entire human genes with a budget of $3 billion. It was hoped that such a project would enable us to understand the nature and diseases of mankind. Upon completion of this Human Genome Project, these scientists discovered a total of 24,000 genes that were presumed to be the blueprint of human genetics. Not long after, the notion is again overturned with the new realisation that these 24,000 genes that make up the human genome is only one percent of the blueprint of the total genes that determine what we are, and how we function. The other 99 percent of genes contributing to the blueprint come from the microbiomes in us.
Do you know that the types of bacteria present in our guts may determine how fat or slim we are? Researchers had recently found two “slim” bacteria known as Akkermansia muciniphilia and Christensella minuta to be strongly associated with slim individuals. The presence of these bacteria in the gut of individuals prevents them from weight gain. These gut bugs help us regulate our metabolism, control the absorption of various nutrients, and even manage our body weight. Further experiment on mice verified that the transfer of the bacteria from fat mice to thin mice via stool-transfer made the thin mice fat, and vice versa.
Researchers had also pointed out that the imbalance of the normal gut microbiomes had been found to be associated with Type 2 Diabetes (T2D). The relationship between our gut microbiomes and the rapid increase of incidence of T2D in the last half a century is an interesting subject of exploration by researchers in recent years. They had pointed out that, whether we have T2D or not, may have something to do with the types of bacteria that are present in our guts. The levels of a group of bacteria called Firmicutes and Clostridia were noted to be reduced in individuals who are having T2D.
T2D and obesity are both major contributing factors to the likelihood of getting a heart attack or stroke – the two health catastrophes with very high fatal outcomes. The type of bacteria present in our gut is not only linked to T2D and obesity but also has a direct role in the development of atherosclerosis that leads to narrowing of arteries supplying our heart and brain. Thus, having healthy microbiomes in our gut can help us in mitigating the risk of getting a heart attack or stroke by mitigating their risk factors as well as their direct effect on the narrowing of arteries to our vital life-sustaining organs.
Recently, alterations in the gut microbiomes and its metabolites had been found to be associated with high blood pressure. Heart failure has also been associated with specific gut microbial species such as increased Escherichia coli, Klebsiella penumoniae, and Streptococcus viridans. One study has shown that patients with symptomatic stroke and transient ischemic attack had altered gut microbiomes with increased opportunistic disease-causing bacteria such as Enterobacter, Megasphaera, Oscillibacter, and Desulfovibrio.
The gut microbiomes can also contribute to substantial variation in blood lipid composition, which can lead to narrowing or occlusion of heart arteries. For example, Firmicutes such as Lactobacillus reuteri are associated with higher good (HDL) cholesterol, whereas the genus Eggerthella is associated with decreased good (HDL) cholesterol.
Truly, our gut microbiome is one of the important factors that determine our health status. They play multiple critical roles including helping our nutrition and energy harvest, maintaining the integrity of our intestinal lining, drug metabolism, immune system response, and protection from harmful microbes. They can also generate microbial products such as short chain fatty acids, lipopolysaccharides, nitric oxide, vitamin K, vitamin B complex, gut hormones, and neurotransmitters, which can affect our bodily functions in health and disease states.
Thus, the father of modern medicine, Hippocrates was right when he said this 2,500 years ago, “All diseases begin in the gut.”
We are in a very interesting era where eating “poop pills” with poop from healthy donors with communities of microbiomes favourable to good health may soon be the ingenious answer to many diseases including some of the diseases with no known effective treatments. Truly, understanding and manipulating the human microbiomes many hold future answers for health and disease.
Dr Victor Ti, MD, MFAM (Malaysia), FRACGP (Australia), Dip P Dermatology (UK), Dip STDs/AIDS (Thailand), Dip. AARAM (USA), LCP of Aesthetic Med. (Malaysia) is an experienced expat specialist generalist (Family Physician) of BH Clinic, Phnom Penh. As a specialist generalist, he is skillful at diagnosing all general diseases and excluding the sinister ones. Apart from the general diseases, Dr. Victor is also known for his skill in skin diseases, sexually transmitted diseases, minor surgery, and aesthetic medicine. He can be contacted via email [email protected] Tel: 023900446 or Whatsapp: +60164122977. Facebook name: Victor Ti.