Mentor's Desk— Stories about life, education, and learning.

Is A Human Being Truly Autonomous? 

We often hear people say, “I don’t depend on anybody. I don’t need anybody’s help. I can completely manage myself.” Truly, this cannot be so. From birth until we leave this world, dependence is essential - physical, emotional, intellectual, economic. Most of it comes from our families and neighbourhood, from outside the individual. Even the physical body we inherit depends on support we rarely recognise. Apart from human cells, our bodies host a staggering number of living entities, mostly in the gut, on which our survival, growth and capabilities depend. Let's see if we are truly autonomous.  

As we enter the world, our mother passes down a protective layer of microscopic companions, bacteria that immediately set up home on our skin and in our internal systems. For generations, we were taught to fear all bacteria as invaders to be scrubbed away. Modern medicine tells a different story. Every person is a living ecosystem, sharing their body with around thirty-nine trillion friendly microbes. Without them, we simply cannot survive. 

Deep in the digestive system, this community works like a pharmacy that never closes. When we eat, simple sugars, proteins and fats are absorbed in the stomach and small intestine, but complex plant fibres pass through untouched - useless to human enzymes, yet a feast for bacteria waiting in the colon. Scientists have even begun engineering strains like E. coli Nissle 1917 to live in the gut and produce medicines directly where needed, with research exploring inflammatory bowel disease, cancer therapy, and metabolic disorders, though much remains experimental. 

As these microbes break down fibre, they produce short-chain fatty acids, notably butyrate — the primary fuel for the cells lining the intestinal wall, keeping it strong and preventing toxins from leaking into the bloodstream. Butyrate also signals immune cells to calm inflammation, while these microbes manufacture Vitamin K and Vitamin B. 

This living workforce also acts as our body's security team. On the skin, residents like Staphylococcus epidermidis occupy space so harmful bacteria can't land and multiply, producing their own antimicrobial peptides as tiny, localised antibiotics. 

From birth, bacteria train our immune cells to distinguish harmless substances from real threats. Without this training, immune systems can grow confused, leading to allergies, intolerances or autoimmune conditions. 

Perhaps most surprising is their influence on mind and mood. The gut and brain communicate constantly through the vagus nerve, and gut bacteria produce or influence most of the brain's chemical messengers. Roughly ninety percent of the body's serotonin is produced in the gut, heavily shaped by microbial activity, while other strains produce GABA, which soothes stress and anxiety. A balanced microbial garden promotes calm and focus; a disrupted one can send distress signals upward, contributing to brain fog, mood swings, and anxiety. 

Modern life, however, is harsh on this inner sanctuary. Decades of ultra-processed, fibre-stripped food have left our microbial partners starving. Stress, poor sleep and overused antibiotics can wipe out beneficial populations within days. Antibiotics are lifesaving against dangerous infections, but unnecessary use can leave the gut's microbial landscape vulnerable for months. 

Restoring this partnership doesn't require supplements or medical intervention - just mindful, everyday care. A variety of high-fibre plant foods gives bacteria what they need to manufacture medicine. Fermented foods like yogurt introduce beneficial live strains. Time outdoors, contact with garden soil and quality sleep help cultivate a richer inner ecosystem. 

For human survival, we require multiple dependencies. We are not truly independent, we are interdependent. Amid rising lifestyle diseases, the answer isn't drastic action or broad-spectrum antibiotics that kill indiscriminately. It's simply remembering not to harm the helpful bacteria within us. They don't need our praise - only our restraint. That would be the truest tribute to the bacteria because of which we are what we are.