The digestive system

Our digestive system consists of the gastrointestinal tract, which is a series of hollow organs that connects the mouth to the anus. It also includes the organs that are needed for digestion such as liver, gallbladder and pancreas. Digestion is needed for all the food that we consume as the food we eat needs to be broken down into smaller components until they can be absorbed and utilized by our body for energy, growth and cell repair.

What are the roles of the digestive system

Each part of the digestive system plays a role in moving the food or liquid through the gastrointestinal tract. To break down food into smaller size, our pancreases will secrete digestive enzymes into our small intestine. The small intestines will then mix the enzymes with the food via a movement called peristalsis. This will help to break down carbohydrates, proteins and fats into smaller molecules for our body to absorb the nutrients. Small intestines are also responsible for the absorption of nutrients. Once this is done, the food residue will move on to the large intestines to further absorb water and to be removed from our body.

What are gut microbiota and why are they important

The small intestines and large intestines contain intestinal microflora, which is a complex ecosystem containing over 400 bacterial species. The balance of these bacteria is the key to good health as they act as a protector to our gut by preventing potential invasion of intestinal lining by harmful bacteria. This gut microbiota also helps in communication between the body and the gut lining which is essential for the development of a healthy immune system. Some of the condition that may affect the digestive system includes:

• Constipation
• Diarrhea
• Bloated stomach
• Heartburn
• Stomach ulcers
• Irritable bowel syndrome
• Gastroesophageal reflux diseas

What are prebiotics?

Prebiotics are special plant fibres that the human body cannot digest. It is described as “a non-digestible food ingredient that beneficially affects the host by selectively stimulating the growth and/or activity of one or a limited number of bacteria in the colon, and thus improves host health”. 

What are the benefits of prebiotics?

Prebiotics feed the gut microbiota and help them to grow and work better. The beneficial intestinal microbes will ferment prebiotics and obtain their survival energy. Therefore, the benefits of prebiotics have links to the benefits of these good bacteria. Prebiotics are also able to modify the gut environment by decreasing the gut pH due to fermentation and as a result, they are able to selectively modify and influence the composition and function of the gut microbiota.

How do prebiotics help with the digestive system?

Just like these good bacteria, prebiotics may support a healthy gut, offer a better digestive system, help in our immune system by keeping bad bacteria in control and preventing bad diseases from growing and spreading. Due to their ability to alternate bacterial growth in the gut, some studies have also suggested that prebiotics are able to reduce the development or severity of atopic dermatitis and eczema in children.

Although limited studies have been carried out on prebiotics, their relationship with human overall health has been an area of increasing interest in recent years. Not all plant fibre can be classified as prebiotics. The commonly-studied prebiotics are inulin, fructooligosaccharides (FOS), galactooligosaccharides (GOS), and more recently human milk oligosaccharides (HMOs).

Where can you get prebiotics from?

Prebiotics can be obtained from various sources and most of them naturally exist in many fruits, vegetables, and whole grains such as:

• Apples
• Asparagus
• Banana
• Berries
• Garlic
• Green vegetables
• Legumes
• Oats
• Onions
• Tomato

Besides dietary consumption, prebiotics can also be obtained from supplements for digestive health that contain probiotics and prebiotics.

Prebiotics are generally considered safe for consumption and they may serve as an alternative to probiotics to a healthy gut. As the saying goes, you are what you eat, or more accurately you are what you feed your intestinal microflora. Both prebiotics and probiotics are needed to support our body in building and maintaining a healthy digestive system and also to support our overall health.

Reference

1. Canny, G. O., & McCormick, B. A. (2008). Bacteria in the intestine, helpful residents or enemies from within? Infection and Immunity, 76(8), 3360–3373. https://doi.org/10.1128/iai.00187-08
2. Davani-Davari, D., Negahdaripour, M., Karimzadeh, I., Seifan, M., Mohkam, M., Masoumi, S., Berenjian, A., &Ghasemi, Y. (2019). Prebiotics: Definition, types, sources, mechanisms, and clinical applications. Foods, 8(3), 92. https://doi.org/10.3390/foods8030092