This is not rollicking sci-fi with some imaginative and dark touches, scrabbling for treasure amid alien detritus. It’s about a real world we live day in day out. This is about science and not for average young adult territory, who might find it boring for the story that it tells. Still, it’s good to know the bug that saves your life and lives with you. We have to start somewhere. No baby is born eating rice pudding (sangom kheer in Manipuri; rather half Manipuri and half Mayang).
Microbes have been around our planet for 3.5 billion years. Multi-celled complex life has been for 500 million years. We, as their offspring appeared merely 200,000 years ago. Microbes (microscopic organisms) are tiny cells, vastly smaller than human cells in which they often live and help us or cause diseases. They are rounded, rod-like or spiral. They are the root of life. While all bacteria (germs) are microbes, all microbes are not just bacteria. They include fungi (eg penicillium that grows in old damp shoes) and green algae (eg kung in Manipuri that grows in ponds).
Speaking about penicillium, I’m very proud that there’s an internationally renowned Manipuri microbiologist Professor Khumanthem’O Ranjana MD, ICMR-IF, Department of Microbiology, RIMS, Imphal, who in 1998 for the first time in India, isolated a Manipuri strain of the fungus Penicillium marneffei from HIV infected patients. It was first discovered in 1956 in Vietnam in bamboo rats. They usually infect patients with AIDS with generalised signs and symptoms. Her finding is of tremendous importance in diagnosing and saving patients in Manipur where the disease is endemic.
That microbes evolved and changed the Earth’s surface and climate since life began is agreed by scientists, but the exact time when life begin on earth based on isotope proportions in organic carbon (Author, The Turin Shroud, 2010), previously understood to be 3.85 Gyr (1996), has yet no general consensus because of lack of oxygen in the atmosphere and the lack of clear evidence for cyanobacteria (oxygen producing green algae) before 2.9 Gyr (2004).(Gyr = Gigayear = 1 billion years).
The way we live and die are changing. Bizarrely for something so clichéd like sexually transmitted diseases (STDs) that are often simple infections by germs and not diseases (ie infections with symptoms) but waiting to pounce on others are giving rise to social mores. Researchers in Canada and Germany have found out STDs are the reason why our prehistory hunter-gatherer ancestors settled to monogamy. This also has led to research that germs (microbes) are not all our enemies. Scientists are working out how the microbial world has been saving our life.
Gliding over the Darwinian evolution, I’ve touched recently on the ‘Plankton and The origin of Forests’ and how humans and forests developed from single-celled microbes that are neither plants nor animals. In the beginning they were minding their own business. Later, they must have evolved to adapt to the landscape. Since Robert Koch established in 1876 that microbes can cause disease (anthrax), we think all germs are horrible and to be eradicated. Only late in human history, scientists are stunning us into silence with the proof that we need microbes for our healthy living. Microbes can also be turned into workhorses for human benefit by altering their genetic makeup eg to produce ‘human’ insulin’ for diabetic patients.
Microbiologists are trying to identify the microbiome (community of microbes that live with us) for what they do for us. DNA studies show we are ecosystems, living in different environments, with a unique set of biotic (living) and abiotic (nonliving) factors. The genes of all human microbiome are considered to be similar to the human genome, as well as to plants and other animals.
Microbes save our lives by defending us from disease producing bacteria. They educate our immune system, guide our behaviour, bombard our genome with their genes to grant us incredible abilities. Some microbes are associated with our good moods. Among the beneficial bacteria, Lactobacillus species, normally found in the mouth, gut and vagina, are superstars like Lactobacillus rhamnosus that acts as anti-depressant.
Breastfeeding mother’s milk contains friendly bacteria that help to build up baby’s normal gut flora. It contains over 700 different types of bacteria, Lactobacillus being the commonest. It also contains “prebiotics” (non-digestible food ingredient normally present in the intestines) ie food for these bacteria. The bacteria species in your colon today are more or less the same you had when you were six months old. About 80% of a person’s gut microflora are transmitted from the mother during birth.
We are permanently covered with a layer of microbes that help us in myriad ways. They help to make vitamins, minerals, cheese, yoghurt, wine, beer. As I wrote earlier, American scientists are going to use the microbe Wolbachia to genetically modify mosquitoes to prevent the spread of Zika virus in America
The release of genetically modified sterile male mosquitoes will reduce the population of zika carrying mosquitoes below disease transmission levels. This microbe Wolbachia manipulates other insects’ sex lives eg it kills male wasps making the females reproduce by cloning themselves. It changes insect sperm so that males only can fertilise eggs that are infected with the same strain (breed) of Wolbachia.
I wrote once, how some doctors in America saved the life of a child when nothing else worked, by transplanting faeces containing the normal bacterial flora to fight the infecting bacteria (Clostridiun difficile)in the child’s intestines. This process called ‘Faecal Microbiota Transplant'(FMT) is now commonly used in the US to treat uncontrollable diarrhoea in both children and adults.
Bacteria are not all nasty. There’re good billions of them in our intestines. When I was in school, doctors in Manipur prescribed vitamin B-complex along with an antibiotic, idea being, to protect friendly gut microbes from the antibiotic. In the West, you can buy “life food” or “Probiotic yoghurt”, teeming with billions of live Lactobacillus, Bifidobacterium and Streptococcus. Probiotic = helpful to life, opposite of antibiotic. Theoretically, they’re meant to give you the right amount of ‘good bacteria’ to fight the ‘bad bacteria’ inside of your gut in the right ratio. Not all yoghurt contains probiotics. There are other types of yoghurt that are heated in such a way that all live cultures are killed.
Talking about Lactobacillus, while filtering out ignorance of childhood, I remember my mother who squeezed lemon juice to boiled warm milk in an unglazed pot, left it overnight when the milk turned into curd (yoghurt) next morning with some greenish yellow fluid. I know now that milk contains lots of things, mainly proteins (casein and whey), fat and water. Normally, the casein in groups (micelles) float around in milk. Since they are negatively charged they repulse each other. When milk is made acidic with lemon juice they become neutral and clump with each other as curd, leaving a sour liquid containing whey.
A recent book, I Contain Multitudes by Ed Young, describes a revolution in biology as a Microbe’s-Eye view of the world. He takes the reader on a grand tour of the microbial world and humans for the benefit of each other. He describes how some bacteria, Vibrio fisceri live harmoniously with squids. These bacteria do not glow when roaming in the sea but will glow blue at night when they reside in the squids’ light organs located on their underside. The light protects squids from predators as they cast no shadows to the bottom of the sea, while the bacteria get sustenance from the squids.
Young explains with splendid examples eg the only bit of flatworm that can’t regenerate is the bacteria-free head. The tail will regrow a brain but brain alone will not produce a tail. The fearsome bee-eating wasp, the female beewolf, passes onto its young a strain of bacteria that themselves produce life-saving antibiotics for the young beewolf grubs.
Bacteria are very crafty in their survival modus operandi though they have no brain or nervous system. They alter their genes to protect themselves like the hospital super bug that is resistant to all known antibiotics – MRSA (Methicillin resistant staphylococcus aureus). It’s called the horizontal gene transfer. About 1:100 people carry them in their nostril without problem. It’s a killer for others. With human ingenuity, a German microbiologist in July 2016, announced a new antibiotic using a fellow bacterium Staphylococcus lugdunensis that can see off MRSA with its toxins.
In brutal honesty, I suspect we might all go bonkers without our microbiome as we depend on them for many of our critical functions. Scientists believe much of one’s personality comes from one’s microbiome other than the family. They have introduced strains of bacteria, like Lactobacillus acidophilus in the form of capsules or tablets that could do away with many of our ills, from gut problems to depression. Multiple projects are going on in sequencing the microbiome. We have to wait to see what they discover in ten years.
Our long-held belief about cleanliness using germ killers to destroy all the microbes is meeting new challenges. Only a tiny minority of bacteria causes human illness. The question is how to distinguish bad from good bacteria in a normal household or clinic. Arizona State University scientists have developed a tool called microfluidic chip that can just do that.