alt Hacker News> This opens up the possibility that the bacterium under investigation could be used as a probiotic to help preserve muscle strength during aging
Maybe, but it's really hard to control for other variables here. They don't know what's causing this bacteria to diminish over time in older adults in the first place.
It could totally just be dietary habits getting worse over time as people let themselves go. Regardless of age, most people already don't eat enough protein and when they do they might not be getting "complete" proteins either (missing amino acids is common with plant-based foods).
For me personally, as I've gotten older I have continued to eat better and more consistently than I ever did earlier in life. I think the long term study of your own life tends to show you that diet is one of, if not the, primary factor in short and long term health and well being.