Can anyone explain the gut / brain axis during grief?

https://complicated.life/blog/gut-brain-connection-how-gut-health-influences-mind-wellbeing/

I found a lot of answers in a book called ‘The Grieving Brain’. It helped me understand the neuroscience of grief.

@gently
And the body keeps the score. Vagus nerve. Try as much upside distraction as you can. Not big. Something that has always pleased you. Good meaningful social interaction really helps.

I've never experienced any of the problems you describe - however. I initially had problems eating. It seemed I was never hungry enough to bother making or buying a meal, Or maybe I just ignored the hunger while I was in deep depression and grief. That lasted for about three months, lost about ten pounds, then started eating again - however, never as well as previously. Now it's a lot of soup and salads, or take out Chinese. My wife was Italian, and wonderful cook, the family enjoyed what I considered the best Italian meals possible for many years. Your question has me wondering if my current habit of not making, or ordering Italian, even when dining at an Italian Restaurant, if possible. Maybe I should find the book suggested by @thereaklenb above.
As to "social interaction" - It has helped me only during the time that I'm actively interacting. As soon as I'm home alone again it's forgotten, and I'm in that deep funk again. It's only been six month, after 72 years together - maybe, as many say - "time heals everything", have to wait and see!

@cece55 Digestive issues are common when experiencing grief. After my wife passed away unexpectedly, I lost about 35 pounds in the 3 months after her passing. Could not eat, so upset losing her and I had digestive issues. In past year, I did put some weight back on, but digestive issues remain but minor compared to a year ago. I found it important to make sure I eat and focus on high protein meals. If possible, plan meals ahead by a few days. Be well.