Bacteria and biomes
Bacteria appear to be simpler than our own cells (they do not have a nucleus for example) and reproduce frequently by simple division into two identical cells. They are incredibly adaptable, and will acquire genetic material from plants, viruses and other bacteria and so can adapt and evolve rapidly.
Bacteria occur in vast populations, generally with many different species in constant (chemical) conversation with each other. These ecosystems are referred to as biomes, or in this case microbiomes. The gut microbiome is the most well known, and has increasingly become the focus of healthy living advice. We also have sophisticated biomes in our mouth, on our skin, in our lungs, in the vagina and many other niches. Each of these plays a key part in the healthy function of their organ.
The gut microbiome helps to breakdown vitamins, nutrients and digest fibre. It is linked to our brain through the vagus nerve, as part of a relationship known as the gut-brain axis. Gut bacteria can produce and influence brain-active neurotransmitters including seratonin which can influence your food cravings, mood and even personality – current studies show that mental health may need a diverse gut microbiome.
Bacteria can produce three generations per hour and any change to their environment can quickly alter the genetic profile of the population. So they are very good at evolving to survive threats. To a population of bacteria, antibiotics are threats: any individuals that can survive an antibiotic prescription (particularly if it is a relatively low dose or the regime is halted early) will reproduce to generate many more with those attributes (Message: if you do have to use antibiotics stick to the prescription and complete the course: it will reduce the risk that you will become resistant to antibiotics when you really need them!). Frankly, it is better not to threaten our bacteria at all unless we really need to: use antibiotics only where there is a clear and pressing danger and a clear bacterial target (they are useless against viruses, fungi and other organisms).
Antimicrobial resistance (AMR) is a result of the overuse and misuse of antibiotics. It is a global health risk that experts say will soon be more dangerous than cancer. There are evidence-based natural approaches that can reduce the need for antibiotics – see Instead of Antibiotics on the College of Medicine site.
In health our bodies and bacteria are in a constant dance of synergy. Sometimes, the scale is tipped and harmful bacteria can become dominant and cause infection,. This risk is reduced by maintaining a healthy biome. For example studies have shown that regular intake of probiotics can help to keep respiratory infections at bay during the winter.