Before diving deep into eating for good gut health, it is important you first understand the physiology and systems that allow your gut to function properly.
Your gut is essentially a tube that starts at your mouth and ends at your anus. This tube consists of an inner hollow portion, called the lumen, surrounded by a very complex outer layer of muscle tissue, nerves and mucosa. This tube runs the length of your mouth, oesophagus, stomach, small intestine and large intestine, and has connections with your pancreas, gallbladder and liver; your guts accessory organs. The three main functions of your gut include transportation, digestion and absorption of food and water.
Learn more here: Digestion 101
GUT HEALTH BASICS
To have a healthy gut means you successfully digest and absorb the nutrients from the foods you consume. If digestion and or absorption is compromised, your nutritional adequacy will be compromised which in turn will affect a myriad of your body functions. For example, malabsorption of iron results in fatigue and reduced immune function, and B12 malabsorption impacts mood and cognition.
Further to this, a healthy gut means you have regular and normal bowel movements and rarely experience GI symptoms like discomfort and bloating. It also means you have an absence of GI illness like intolerances, coeliac disease and inflammatory conditions.
Often underrated and less commonly spoken of is the integral role your gut plays in your immune status. In fact, a huge portion of your body’s immune system is in your gut and includes having a strong gut barrier, producing normal amounts of mucus to cover your gut lining, having normal numbers and activity of immune cells and having immune tolerance. Of significant importance to your gut health, is the health of your gut microbiota.
You can’t have gut health without microbiota health. It comprises that world population of microbes harboured (mostly) in your large intestine, which assists your digestion and absorption, supports your immune function and gut integrity, produces numerous beneficial nutrients and inhibits the growth of pathogens. Did I mention their influence on your mood and feelings? Yes… they play an integral role.
Learn more here: The gut-mind connection
In a nutshell, a normal gut microbiota composition and function is characterised by a rich number of bacteria, a great diversity in bacterial species types, as well as the gut microbes functioning with vitality.
In relation to food choices, processed and animal-based foods dampen your gut environment, via slowing digestion, altering your microbiota profile and influencing GI symptoms. These factors in turn can damage your gut health by causing uneasy symptoms like bloating, discomfort and constipation, as well as degrading your symbiotic bacteria. Mechanisms behind this include the fact that processed foods are predominantly low in fibre. This interrupts GI motility, microbe health and bowel habits. Processed foods also often contain varying amounts of additives, such as artificial sweeteners and emulsifiers. Both of these have been shown to disrupt your gut microbiota, as well as increase inflammation. Greasy high fat foods have similar effects, slowing digestion, influencing GI symptoms as well as reducing beneficial gut microbes. High intakes of animal foods have also been found to negatively alter your gut microbiota, contributing to the growth of disease-associated bacterial species, like Bilophila wadsworthia and A. putredinis, as well as reductions in numerous beneficial bacteria.
Learn more here: Gut irritants
Plant-based wholefoods favour your gut health, particularly through their way of enriching your gut microbiota diversity and vitality.
You can read a bunch on this here: Gut health, fibre & Prebiotics