For anyone familiar with the bleak early days of this blog back in November / December last year when the drama of this 2020 was still a thing of science fiction, I mentioned I was reading a book called Gut by Giulia Enders. Well it turns out I’m still reading it. This longevity isn’t because it’s difficult, quite the opposite in fact or boring, also quite the opposite. I just get distracted and either read other things or am too busy, but keep dipping into it when I fancy reading some more. This morning I read a little on Toxoplasma gondii. For anyone Scottish it is simply unimaginable not to be familiar with the film Trainspotting, and for those who are, they will be aware of this bacteria from the character Tommy catching it from his cat before dying from it and heroin. Naturally then this little mini-chapter grabbed my attention.
It turns out it’s actually an incredibly interesting bacteria which considering it’s size can have an enormous affect on it’s host. Cats, not all of course, carry this bacteria and it is spread to humans usually through their faeces in cat litter trays. It can find it’s way onto raw vegetables in your garden if a cat has either done it’s business or died within, as well as through animals such as pigs or chickens when we eat them. The chances of humans contracting toxoplasma are, in percentage terms, about as high as your age and about a third of the global population have them. We’re talking a reasonably high probability and billions of people. They don’t have an overly negative immediate affect on the human body, sometimes creating flu-like symptoms, so not too dissimilar to this virus for many people. Pregnant women though have to be very careful as it can damage the unborn baby and lead to miscarriages. What is fascinating about it though is the affect it has on our behaviour.
A study at Oxford University discovered rats, who would ordinarily and instinctively avoid cats urine, would when infected with toxoplasma not only be fearless of the cats urine but actively stay near it. This bacteria removed certain inhibitors in the rats brain, the bacteria which wanted to exist within the cats gut was offering up the rat, it’s host, as dinner and sacrifice. This tiny bacteria was influencing and arguably controlling the actions of a far larger creature. The rats were indifferent to human, dog and other varieties of urine, the rats and their cat loving bacteria interested in cats piss alone.
Like anything of this ilk proved on rats it wasn’t long before it was tested out on humans. She refers to a large scale experiement in which 3,890 soldiers from the Czech army were tested for toxoplasma and then over the next year the numbers of accidents they were involved in was recorded and analysed. It turned out those with the bacteria, and particularly those with rhesus negative blood type, were involved in the highest number of accidents. It turns out, and I’m going to crudely paraphrase this, that when infected the immune system activates an enzyme called IDO which breaks down a substance the invaders like to eat, forcing them to become dormant. Unfortunately this substance is also vital in the creation of serotonin, a lack of which is linked to depression and various anxiety disorders, as well as lethargy and general indifference. IDO is also highly activated during pregnancy, hence the link, and this and the immune systems response can sometimes treat the baby as a semi-alien which leads to miscarriages.
To take this further, the toxoplasma bacteria hide away in a few places but predominantly the amygdala section of the brain. This is also the area in which our fear receptors exist. This is also seemingly the part of the brain responsible for the decision making process, if you’re a parasite attempting to promote self-destructive tendencies, this is probably the best place to exist. Humans with toxoplasma were also found to have a different response to cats urine than those without, men especially seemed to prefer it with women less so. Interestingly the proportion of carriers among schizophrenics is about twice that among non-schizophrenics.
Science and medicine move slowly, unless you’re creating vaccines for pandemics of course, so it’ll still be a long time before these factors are tested for regularly and this understanding of behaviour and bacteria become common practice. It does though make you think about certain behaviours in people that just seem illogical and insane. Why someone could be so reckless is now slightly less inexplicable. Or even perhaps why you yourself have done so many stupid things over the years. I’m not suggesting we all go out and sniff cats urine to check our response of course, but this does open possibilities for how we view and understand behavioural patterns. This is just one parasite and if it’s possible for this one to create these suicidal and reckless tendencies, how do we know other bacteria don’t also affect our behaviours. There is so much we just don’t understand about our bodies yet we behave as if we know it all. The gut and the varieties of little enzymes and bacteria within can change everything about us yet we give it next to no attention. I am barely even a layman in regards to these things but it is exciting that we are starting to really see some movement and understanding of things within us that could potentially change our lives for the better. Who knows, if we can positively change our own behaviours with this, maybe science could save the whole world in a most highly unexpected of ways too. Either that or the cats may just take over the world after all.