Royal Institution. Abermarle Street, London. I’ve come to a discourse evening. The term discourse sounds like people are going to start arguing. British scientists throwing things at each other. Can’t wait. Birthday present to myself.
Tonight’s discourse is about immunology. After my degree, I almost did a MSc in immunology. My undergrad dissertation looked at a gynaecological disease in female dogs that may have had an autoimmune aetiology. Sexy or what. I was originally supposed to count lobsters in the Cardigan Bay for my dissertation but the summer was too stormy for underwater visibility. My professional fate was decided by the weather. Typical.
This started an interest in immunology and an almost MSc. until I saw a job advert for a clinical embryologist. In the end, despite the reproductive focus, I still think immunology is the sexier science. How bodies fight disease changes from instant attack to learned response, where a whole bunch of cells are just waiting for disease to strike like Italian gangsters who never forget a face. Hello Godfather! Then, the other side of immunology is how our bodies can turn on ourselves. It’s so Mutiny on the Bounty. We could find a movie for every immunological drama.
Turns out the lecture tonight was largely about the microbiome. The microbiome is the micro-flora in your gut. It generally means the bacteria that live in your digestive system, but can also be viruses and other micro-organisms too. Ok, a scaling session since the lecture started with it and you always remember the first fifteen seconds. If an immune cell is the size of a human, bacteria are the size of rugby balls. Viruses are AA batteries. Tiny virus particles are about the size of paracetamol tablets.
This microbiome has a massive effect on our immune system. How it plays out and whether each type of healthy micro-organism has its own immunological effect – that bit wasn’t clear to me. To be honest, I don’t think Professor Sheena Cruickshank really knows herself. And I’m not criticising her. That is one brilliant lady from Manchester University, running a world class lab. It’s just that scientists are only beginning to understand the relationship between our bodies and the particular microbiome we have. We do know that problem bacterium Clostridium difficile has a specific way of restricting T-cells – a key immune cell for fighting disease. No wonder the sneaky hookworm promotes the presence of C. difficile in our microbiomes. Having C. difficile around is akin to the hookworm having an army. Oh and spoiler alert – Prof Cruickshank is not grossed out by parasites. At all. We watched a 3D movie she was really proud of. The movie consisted of entering the gut and hanging out with burrowing whipworms. Good times.
So, even though I haven’t left the lecture with a total understanding of the basics between our micro-flora and our immune system, I get this. Ninety-percent of our immune system resides in our gut. There are many examples which show our immune system needs particular microbiomes in our gut to stay healthy. In particular, immunotherapy for cancer treatment has shown levels of fibre in our gut makes a big difference in making the immunotherapy effective. Conversely, cancer patients who had antibiotics prior to immunotherapy showed a much less effective response to their immunotherapy.
This would suggest the immune system needs a healthy and varied microbiome in order to be effective. Healthy octogenarians are another example. Healthy octogenarians are found to have a more varied microbiome than younger age groups who aren’t as healthy. Can they pinpoint their longevity then to their impressively cultured microbiome? It’s a fascinating question.
Finally, here’s the million-cellular bacterial one – what changes the microbiome in our guts? Well, that one’s easy. What we eat.