2019 Blood test results - more kidney function degradation :(

I have been suffering on and off from intestinal inflammation over the last four months, causing abdominal pain and discomfort. The initial attacks seem to have been triggered from eating a peanut and dried fruit trail mix (on four occasions after eating said trail mix I had symptoms within a few hours / next morning) but it's not clear whats causing the symptoms to remain three months later. An ultrasound shows no other problems except the inflammed small intestine. A specialist ordered lab tests (which I was overdue for anyway), antiparasite medication (which had no effect), and an anti-inflamation medicine, which also has had little effect. Unfortunately the lab tests show a ~10% degradation of kidney function compared to tests a year ago: I feel this degradation of kidney function may be related to the the intestinal inflammation (maybe whatever is causing this is also causing kidney inflammation) and so hope to get this resolved as soon as possible and start a renewed effort to improve my overall health with daily exercise and more careful attention to diet! Will test again after a few months of dedicated wellness activies and see if it shows any improvement.

Kidney degradation not inevitable?

The following article says a recent study shows that while kidney function tends to decline with age in more developed societies, this is not necessarily the case in less developed societies. That is, it seems like there may be something (or many things) about our "advanced" lifestyle which causes kidney degradation with age. No clues as to what that might be yet but adopting a more "primitive" diet (less processed food, more fruits and vegetables) certainly seems like it would probably benefit the kidneys.

https://www.economist.com/science-and-technology/2019/02/13/loss-of-kidney-function-in-old-age-is-not-inevitable

Since being diagnosed with chronic kidney disease (CKD) almost 10 years ago I have fortunately so far managed to avoid further measurable kidney degradation. My diet has basically been:
- Relatively small amounts of animal proteins (no beef/pork/chicken/etc., fish/seafood maybe twice a month, eggs once week, yogurt and cheese a couple of times a week, no milk).
- Limited wheat (I found that wheat seems to cause me abdominal swelling).
- Lots of fruit, vegetales and nuts (bananas, avocados, broccoli, carrots, apples, almonds, unsalted peanuts, beetroot, lettuce, tomato, beans, etc.).
- Low sugar and salt (no added salt in cooking. Avoid high salt foods).
- A certain amount of starchy foods every day: Rice, corn, oatmeal, sweet potatoes, potatoes.