Hello readers! I apologize, I haven’t added a link to a good research article in quite a long time.
This one, by Christian Jobin, was published earlier this year in Science. It’s essentially a summary of more detailed work that is referenced in the article, and I include it because the language is plainer than those works. Here is the link to the article: http://science.sciencemag.org/content/359/6371/32.long. If you can’t download it for free from your library, try contacting the author to see if he will share a PDF (it is ridiculous the prices journals charge for paywalled articles, especially since authors are not only not paid, they often pay page charges for publication).
Essentially, the article describes work demonstrating that different cancer immunotherapies can be altered in the presence of different species of gut bacteria. We are not yet at a “This bug helps cancer immunotherapy, and this bug is bad for it” stage- and it is possible that an assortment of bacteria can all do similar things and have analogous effects on the human immune system. Right now we are at the stage of finding out a signal in one study for bug X and a signal in another study for bug Y, but people do not actually know what it is exactly about bugs X and Y that cause them to exert their effects. I have one hypothesis, others have other hypotheses, often supported by some data, and it will take another decade of research before we are past the kind of probiotic blitzing you see with fecal microbiome therapy (just replace everything) to the kind of targeted, very specific therapies designed to exert specific effects that some unscrupulous marketers are already claiming to sell.
It’s also very likely that a person’s genetic makeup influences all of this, as does their diet. So predicting the effects of any given bug X probiotic delivered to a human gut is right now not reliable- anyone claiming they can do this is probably trying to sell you something. Don’t buy it.
Most people reading this site probably want to know what they can do to help their immune system fight off disease, or stay healthy. I would argue that eating well (lots of fresh veggies, not too much processed meat, a reasonable amount of fibre, not too much sugar and fat), exercising, getting enough sleep, minimizing stress, and, if you want a probiotic, a dairy or nondairy yogurt containing live cultures is probably good enough for most people. I can’t really recommend a probiotic product, though lots of them are on the market and some might have been clinically tested by now. Most of them can’t hurt you, if used as directed, and if your immune system is not severely compromised, so talk to your doctor about giving one a try.