As a result of damaged intestinal lining there is increased intestinal permeability which is called leaky gut syndrome. For a layman, it can be explained like this- whatever the food that we eat goes into the stomach and digestion process starts, from the stomach it goes to intestine where all the absorption of digested food and nutrients happen. This intestine is like a filter which allows only a selective food particle, to be absorbed into the blood, but when this filter is damaged all the unwanted substances like bacteria, undigested food, toxic waste products get absorbed into the blood which can trigger our immune system.
Our immune system is like an army on alert which on finding any foreign particle in the blood would attack. Now due to leaky gut when all the unwanted substances are absorbed into the blood our immune system would react to all of those substances and would lead to systemic inflammation in the body.
Systemic inflammation is the main reason for all the chronic diseases like autoimmune and allergic diseases which are psoriasis, eczema, food allergies, asthma, allergic bronchitis, sensitive skin, rashes, flushes, achy joints, rheumatoid arthritis even autism.
The main factors involved can be summarised into 4 parts Diet, Chronic stress, chronic inflammation and Bacterial imbalance.