Isn't the general advice to ingest a large variety of lactobacilli, as opposed to large quantities of just one bacillus? When I made kefir in my kitchen, I read that the cultures can contain up to 80 different genetics. Whenever I research lactobacilli, the term diversity comes up.
I gather that kefir grains are like big balls of mud, picking up lots of varieties of microbes. Over time, however, I’d guess that the number of strains might deteriorate due to more homogeneous growing medium and controlled kitchen environment.
I’ve had a lot of kefir grains from different sources over the years, and many that you order online seem to be weak and not thrive. By contrast, I’d gotten some big healthy grains from a friend of a friend who’d been culturing them in raw milk in rural MT for a lot of years, and those things were monsters that grew large and divided often. They led me on an on- again off-again quest to find such excellent grains.
I’ve heard of people introducing their grains to e.g. Icelandic skyr cultures, which results in the permanent colonization of the kefir grains by particular microbes. The skyrified kefir being qualitatively different. I could see getting a lab strain of reuteri and similarly training kefir grains to incorporate this as part of the colony.
Diversity does seem to be a good thing, but that said, some of the reported properties of this particular strain seem especially interesting.
I think taking a single strain is not something you'd want to do long term, I'd assume it's better just as a short course to try and improve your gut bacteria balance, if you're having problems or have just had antibiotics. With a good balanced diet (prebiotic fibre etc.) I don't think people should really need to constantly be taking probiotic tablets, but kefir and yoghurt seem good generally.
