An overreactive immune system can lead to allergy, sensitivity and even autoimmunity, while an unresponsive or sluggish immune system leads to an increased risk of illness. It’s a fine balance which requires a good varied diet, and a strong and diverse gut microbiome.
Our microbes break down fibre by fermentation in the colon, producing chemicals (short chain fatty acids – butyrate and others) which help reduce inflammatory conditions, and energise and communicate with the body’s immune cells, most of which are in the gut lining. When these SCFA reach the cells in our gut, they provide them with energy, keep them alive, and promote replication. They send signals to our immune cells, prevent inflammation, and keep allergies in check. These are the cells that sense when there’s an infection and send certain key white blood cells to the site of the infection.
SCFA make the gut barrier and gut lining really strong, and are important for programming the immune system. People are told they have a leaky gut, and this is what it’s referring to. Recurring infections ,poor diet and stress can cause the contents of the gut to leak into the our blood, causing further inflammation. These SCFA can spread around the body and affect other places. It’s thought that they send signals via the vagus nerve, which connects the gut to the brain, and help modulate brain immune cells.
These chemicals produced, like SCFA, are now called post-biotics, and are being suggested as a health supplement.
Good gut health needs a wide range of bacteria and microbes, and when we don’t, our immune system suffers.
Chronic inflammation in the brain is linked to depression and Parkinson’s disease.