They found that weight loss surgical intervention, such as bariatric surgery, reduced the amount of endotoxin in the blood
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“Leaky gut” happens in the ileum, just after the stomach. Replace the top few inches, and digestion starts happening without leaky gut again. However, without a change in diet the new section of upper ileum becomes just porous as the old section.
People need to undergo a period of training BEFORE bariatric surgery, and their change in lifestyle must be permanent.