There is lots of anecdotal evidence that ketones help lungs function better and promote healing. Your body will produce its own ketones during fasting or when on a very low carbohydrate diet. A shortcut is using ketone esters. We were able to improve my wife's oxygen levels in the ICU. After fasting she went from requiring 85% oxygen down to 55%. You can read more details here . I wish I'd of known about ketone esters as that can go into effect within half an hour vs 18 to 72 hours of fasting. My sister suffered for months from respiratory issues and other symptoms after having COVID-19. After trying a strict low carb high fat ketogenic diet, within 2 days felt much better. She's since added some intermittent fasting to help lose weight and added ketone esters. Her lungs are doing great and other symptoms are gradually now dissipating. Others are having similar experiences. Unfortunately, there are no completed clinical trials on humans. ...