Let’s love fibre- Chapter 1: Soluble Fibre
Fibre consists of non-digestible carbohydrates which are not hydrolyzed or absorbed in the small intestine, but they pass to large intestine .
In the UK, the daily recommended dietary intake for fibre is 30g/day but the majority of the population consumes less than 20 grams/day .
Fibre is so important and underrated it deserves more than a post! Chapters 1 & 2 will be dedicated to the biological mechanisms and food sources of soluble and insoluble fibre, respectively. Chapter 3 will be about potential effects of fibre intake on weight management.
Soluble fibre can dissolve in water and form a gel-like substance . In the large intestine, it undergoes fermetation by bacteria to produce short chain fatty acids (SCFAs) .
Good food sources of soluble fibre are carrots, pears, bananas, psyllium, beans, oats, citrus fruit, apples and barley .
Soluble fibre could help with keeping LDL cholesterol levels under control.
In the small intestine, soluble fibre can bind to bile salts and then both are secreted in faeces. Then, liver cells need to use more cholesterol to synthesize bile again. In order to “get” more cholesterol, LDL receptors are created on the liver cell surface. LDL cholesterol, which is considered as “bad” cholesterol, binds to these LDL receptors and enters into the liver cells. As a result LDL cholesterol blood levels are reduced. It is also possible that SCFAs can reduce cholesterol synthesis in the liver by decreasing the activity of HMG CoA reductase, an enzyme which participates in cholesterol synthesis .
Soluble fibre could help with regulating blood glucose and insulin levels after a meal.
When a meal contains soluble fibre, other nutrients and substances of the food, including glucuse, enter the gel which is formed by soluble fibre. As a result, their absorption into the blood stream is delayed. When glucose absorption is slowed down, insulin secretion from the pancreas is reduced as well .
Gut epithelium health and inflammation
Butyrate, one of the SCFAs, provides the epithelium cells of the large bowel with energy. It also has a role in maintaining the integrity of the small and large bowel. As a result, bacteria and other pro-inflammatory molecules cannot easily pass through the intestine wall. SCFAs could have a role an appetite regulation, as we will discuss in chapter 3 .
It could take weeks to cover the research on soluble fibre, but I hope you got a good idea on how important in could be. Thank you so much for reading and stay tuned for Chapter 2!!!
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