It’s the hormone/nutrient/total health link, once again. Hormones, nutrients, and food function (and dysfunction) together, and in so doing affect multiple tissues, especially our gut walls. And brains. (Safe Hormones, Smart Women (Awakened Medicine 2010), Journal of Physiology 2009 American Journal of Physiological Gastrointestinal & Liver Physiology 2011 Microvascular Research 2011)
Perhaps yet another way that antibiotics potentially damage gut linings is not only by killing friendly bacteria, but they may also injure JAM-A cells. I recommend to people that need to take antibiotics that they add some thiamine along with vitamin A to their probiotic regime to protect their gut walls. It also seems prudent to do in other situations that can erode gut linings, such as with chemotherapy and in chronic use of NSAIDs (non-steroidal anti-inflammatory drugs) and even aspirin.
It may also be that after a serious illness, surgery, or accident, especially if we are already on hormone replacement, hormone levels, that could have shifted due to the stress, should be retested. Of course, JAM-A cells are not all that simple. JAM-A cells protect other tissues, not just the intestinal tract, such as diverse cells in the brain, thyroid and lungs. But in certain situations, JAM-A cells may even protect cancer cells, not something we like to hear. So the unfolding story of JAM-A is, of course, complicated. But inside our guts, and inside our brains, we want our JAM-A to keep jamming away and to protect us.