The garbage passed off as food today and the high rates of digestive disorders plaguing the nation make it clear that the importance of the digestive process is not understood. Digestion is a process that can affect our daily quality of life, playing a direct role in our mental health and mood.  In essence, digestion is where our health begins, and recent research has blatantly illustrated this fact. Let's look at how the digestive system performs its function and discuss the key facts you need to know when seeking to protect your digestive health.
The Digestive Process
The digestive process involves three basic steps: the cephalic phase, the gastric phase, and the intestinal phase. Here are some of the main focus points associated with each phase:
- The Mouth. Upon chewing, enzymes in the mouth begin the digestive process by breaking down food. Amylase is one of the main enzymes in saliva that aid in the digestion of starch (carbohydrates).
- The Esophagus. This long, muscular tube aids in the passage of food from the mouth into the stomach. Hydrochloric acid will further break down food particles while killing microbes and denaturing proteins. Due to the high acidity of hydrochloric acid, a protective mucosal layer of tissue lines the stomach, protecting it from acid erosion and gastric ulcers.
- The Small Intestine. Once food has traveled to the stomach and been subjected to the actions of hydrochloric acid, the contents then travel to the small intestine. This is the main organ that is responsible for absorbing calories, vitamins, minerals, fatty acids, and proteins. Small finger-like projections called "villi" line the small intestine to offer protection and facilitate absorption. The small intestine also hosts a wide range of beneficial bacteria responsible for digestion, specifically Lactobacillus and Bifidobacteria.
- The Large Intestine. This is the final stage of the digestion process. Once nutrients have been absorbed by the small intestine, the leftover wastes travel to the large intestine before being eliminated. Water and salts are reabsorbed before elimination.
While digestion requires the three phases listed above, it also requires four essential components – stomach acid, enzymes, probiotics, and prebiotics.
Digestive enzymes break molecules into smaller parts so they can be absorbed by the body. These enzymes are categorized as:
- Protease - breaks down protein into amino acids
- Lipase - catabolizes lipids (fats) into fatty acids
- Amylase - breaks down carbohydrates, starches, and sugar into simpler monomers
Those that are deficient in these enzymes, or those that suffer from an impairment in enzyme function, may benefit from enzyme supplementation. 
These bacterial colonies, Lactobacillus and Bifidobacteria being the most common, play an essential role in digestion. Probiotics aid in the synthesis of vitamin K, B12, and biotin (B1), contribute to the digestion of foods, denature proteins, and kill off hostile microbes. Some studies even suggest that probiotics may aid in balancing mood.    This effect is observed in relation to serotonin, a neurotransmitter found mainly in the gastrointestinal system.
- Jane A. Foster. Gut Feelings: Bacteria and the Brain. Cerebrum. 2013 July-August; 2013: 9.
- Roxas M. The role of enzyme supplementation in digestive disorders. Alternative Medicine Review. 2008 December;13(4):307-14.
- Farmer AD, Randall HA, Aziz Q. It’s a Gut Feeling - how the gut microbiota affects the state of mind. The Journal of Physiology. 2014 March 24.
- Benton D, Williams C, Brown A. Impact of consuming a milk drink containing a probiotic on mood and cognition. European Journal of Clinical Nutrition. 2007 March;61(3):355-61.
- Desbonnet L, Garrett L, Clarke G, Bienenstock J, Dinan TG. The probiotic Bifidobacteria infantis: An assessment of potential antidepressant properties in the rat. Journal of Psychiatric Research. 2008 December;43(2): 164-74. doi: 10.1016/j.jpsychires.2008.03.009.
- Roberfroid MB. Prebiotics and probiotics: are they functional foods? The American Journal of Clinical Nutrition. 2000 June;71(6 Suppl):1682S-7S; discussion 1688S-90S.
†Results may vary. Information and statements made are for education purposes and are not intended to replace the advice of your doctor. If you have a severe medical condition or health concern, see your physician.