A sedentary life quietly starves your gut microbes: inactivity can lower microbial diversity and tilt your metabolism unfavorably, independent of how much you eat.
Chemotherapy targets fast-dividing tumor cells, but it also bruises the equally fast-renewing gut lining and microbiota — so protecting your gut flora is part of supportive care.
In Crohn's disease the response to FMT is weaker than in colitis, so it stays investigational and shows the most promise in the biologic-naive, ileocolonic subgroup.