Season 1 - Episode 5

Helpful Links

This podcast was inspired by the colorectal cancer alliance. According to their website, “The Colorectal Cancer Alliance is fiercely determined to end colon and rectal cancers within our lifetime. Together with a nation of passionate allies, we advocate for prevention, magnify support, and accelerate research to stop this disease.” They are found by the web address of ⁠colorectalcancer.org⁠. Please check out the link to donate or support this nonprofit. 

Transcript

Introduction

Hello, welcome to mirroring medicine with Kodi and Isabel! Today we will be discussing the human gut and the colon and how complex and fascinating this system is. We will be discussing the function of the colon and the gut, the different conditions that people may have concerning the colon and gut (including what are some contributors to it), and finally some screenings that people may perform for prevention and sustainability of a healthy colon/gut. 

This podcast is meant to provide an overview and it is not comprehensive, we will be going over the tip of the iceberg in regards to this topic and we recommend the audience researching this topic even further. 

This podcast was inspired by the colorectal cancer alliance. According to their website “The Colorectal Cancer Alliance is fiercely determined to end colon and rectal cancers within our lifetime. Together with a nation of passionate allies, we advocate for prevention, magnify support, and accelerate research to stop this disease.” They are found by the web address of colorectalcancer.org. Please check out the link to donate or support this nonprofit who help provide support to those who are at risk or would qualify for that. 

Citations can be found here: 

What is the Human Gut and What does it do?

So what is the human gut, it is the gastrointestinal (GI) track. These are hollow organs that allow food to pass through during digestion. The hollow organs that make up the GI tract are the mouth, esophagus, stomach, small intestine, large intestine, and anus. I will go into these hollow organs into more details. 

We will go through the entire hollow organs starting with the mouth. The mouth is where food enters the digestive system. Upon entering the salivary glands will secrete saliva. This is to lubricate the mouth and aid in the first step of digestion. The breakdown of sugar. Interestingly the enzymes involved in this process our known as the salivary amylase which is a glucose-polymer cleavage enzyme that is produced by the salivary glands (Peyrot, 2016). The most abundant protein in human saliva is the digestive enzyme α-amylase, this enzyme cleaves large starch molecules into smaller starch molecules. 

Saliva is very important for the mouth as it hydrates mucosal tissues, removes cell and food debris, buffers oral pH, lubricates the oral cavity aiding mastication and preventing dental wear, protects teeth against demineralization, has studied antimicrobial activity (Peyrot, 2016).

There are three types of salivary glands in the mouth: the sublingual, submandibular and parotid. The sublingual glands are beneath your tongue. The submandibular glands are underneath your jaw but will secrete saliva underneath the tongue. The parotid glands are located in front of your ears.  Starches such as sugar, rice, and fruit will begin breaking down at this step.

Moving down into the esophagus, this is an elongated hollow organ that connects directly to the stomach. This organ has no digestive enzymes that are secreted meaning that no further digestion occurs at this step. The main job of this organ is to assist in peristalsis the mechanical movement of food through the digestive tract.

Now moving on to an organ that you are all familiar with, the stomach. The stomach is connected to the esophagus through the esophageal sphincter which is muscle that connects the two. It's a j shaped organ where digestive enzymes break down food. Notably, roughly 20% of all fat is broken down in this step. The enzyme participating in this organ is the gastric lipase.  The bottom of your stomach connects to your small intestine. Chyme, which is the acidic mixture of gastric juices and semi-digested food, enters the small intestine.

The small intestine uses peristalsis to move chyme through. This organ supports the digestion of protein. The main enzymes are chymotrypsin and trypsin. Trypsin works specifically in the hydrolysis of peptide bonds between amino acids lysine and arginine. Whereas, Chymotrypsin also hydrolyzes amides and esters of these aromatic amino acids such as tyrosine, tryptophan, and phenylalanine. Interestingly, Trypsin activates other protein-digesting enzymes called proteases. A protease is an enzyme that breaks down protein. These enzymes work together in the small intestine to facilitate the process of protein digestion. 

The small intestine has three parts: the duodenum, the jejunum and the ileum. These parts together make up a hollow tube that is approx 20 feet long. In order for this to fit into the abdomen it is folded various times. This organ absorbs vitamins, minerals, carbohydrates, fats, proteins that are needed by the body to prevent them from being excreted. Water is also absorbed at this step. and water from food so they can be used by the body. The small intestine is part of the digestive system.

Fun fact about the gut microbiome. I want to shed light on a relatively recent bacteria species that has made headlines Akkermansia muciniphila. This is a species of Gram-negative anaerobic mucus-layer-degrading bacterium that colonizes the intestinal mucosa of humans and rodents. This bacteria is part of the Verrucomicrobia phylum. This bacteria colonizes the human gut in early life, and at adulthood can make up up to 3% of the gut microbiome. According to the article, “Akkermansia muciniphila and Gut Immune System: A Good Friendship That Attenuates Inflammatory Bowel Disease, Obesity, and Diabetes” , Metagenomic data have shown an inverse correlation between the abundance of A. muciniphila and diseases such as inflammatory bowel disease (IBD), obesity, and diabetes. The disruption of the integrity of the intestinal mucosa drives the development of inflammatory bowel disease (IBD), such as ulcerative colitis (UC) and Crohn’s disease (CD), which are chronic idiopathic inflammatory diseases characterized by an exaggerated immune response to gut microbiota, resulting in tissue damage. (Rodrigues, 2022) This is mentioned only to highlight how in addition to a healthy diet, maintaining the integrity of the gut microbiome plays a huge role in preventing gastrointestinal diseases and syndromes. 

Charity of the Podcast 

This podcast was inspired by the colorectal cancer alliance. According to their website “The Colorectal Cancer Alliance is fiercely determined to end colon and rectal cancers within our lifetime. Together with a nation of passionate allies, we advocate for prevention, magnify support, and accelerate research to stop this disease.” They are found by the web address of colorectalcancer.org. Please check out the link to donate or support this nonprofit who help provide support to those who are at risk or would qualify for that. 

What is the Colon and What does it do?

Firstly, I want to go into the anatomy of the colon and more importantly the large intestine. In digestion, food goes through your throat, esophagus, stomach, small intestine, large intestine, before excretion through the anus. The colon is only one part of the large intestine. The large intestine includes the colon, rectum, and anus. The large intestine absorbs and reuptakes water/salts to create a final waste product. [1]

With this being said, the colon has several different parts including the cecum (where the appendix hangs off this structure), ascending colon, transverse colon, descending colon, and sigmoid colon. The colon in specific removes water and some nutrients/electrolytes from partially digested foods to form a stool (or more commonly known as poop) [2]

Additionally, colon cancer is a very prevalent disease that typically affects older adults but could happen at any age. Previously mentioned in the breast cancer podcast, cancer is the overgrowth of cells in which they do not have the regular stop signal, so these cells continue replicating. Colon cancers usually occur from polyps. Polyps is a term that refers to a small clump of cells that form inside the colon. These polyps can turn into colon cancers. Removing these polyps when catching it early enough can help prevent colon cancer. According to the mayo clinic, there are some specific symptoms that people may experience. This includes a change in bowel habits (a lot of diarrhea/constipation), bleeding in poop, discomfort in belly area (cramps, gas, pain), feeling that bowel doesn’t empty all the way during bowel movement, weakness, losing weight without trying. [3] Colorectal cancer is one that references a cancer that combines both colon and rectal cancer. 

Furthermore, here are some statistics on colorectal cancer and/or colon cancer. Did you know that colorectal cancer is the fourth most commonly diagnosed cancer in the US and the second leading cause of cancer death. 152,810 people in the US have been projected to be diagnosed with colon cancer in 2024 and 53,010 will die from the disease. Did you also know that it was also the 4th most common cancer in the US amongst men and women combined? It is currently rising in young adults in the amount of 10 percent of colon cancer cases are diagnosed in people under 50 [8]. Did you know that there is a disproportionate burden of colorectal cancer in african americans approximately more than 20 percent higher than in caucasians with a larger difference in mortality. [11]

To add on top of that there are some risk factors for colorectal cancer. This includes having a first-degree relative (parent, sibling, or child) with a history of colon or rectal cancer, having a personal history of colon, rectal, or ovarian cancer, adenomas (polyps 1 cm or larger), inherited changes in genes that increase risk of familial adenomatous polyposis, lynch syndrome (hereditary nonpolyposis colorectal cancer), ulcerative colitis (a long-term inflammatory bowel disease that causes ulcers to form in the lining of the colon and rectum), crohn’s disease (inflammatory bowel disease that causes inflammation in the digestive tract) for 8 or more years, 3 alcoholic drinks or more per day, smoking cigarettes, having obesity, and black people have a higher risk of developing colorectal cancer according to the NIH national cancer institute. [4] 

Plus, there are some screenings for prevention of these cancers. The screenings of these cancers are the digital rectal exam (DRE) which is an exam of the rectum. In this screening, a medical professional inserts a lubricated finger into the rectum to feel for lumps or anything unusual. A colonoscopy is a procedure that uses a colonoscope to look inside the rectum and colon for polyps, abnormal areas, or even potentially cancer. A biopsy sample might be harvested to see if the sample is cancerous. Immunohistochemistry uses antibody staining that binds to a specific marker in the cancer tissue. 

According to the CDC, it is recommended that people should start screening for colorectal cancer soon after turning 45 years old then continue getting screened at regular intervals. People should get tested earlier than 45 years old if you have IBS, personal family history of polyps or cancer, lynch syndrome, or famillial adenomatous polyposis. A colonoscopy should be taken every 10 years for those who do not have increased risk. A CT colonography should be taken in 5 years. [12]

Finally, there are some treatment options for colorectal cancer and/or colon cancer are: 

surgeries that includes polypectomy (if the cancer is found in a polyp), local excision (local removed), resection, cryosurgery, chemotherapy, or radiation therapy. 

Citations

1. Cleveland Clinic. "Colon (Large Intestine)." Cleveland Clinic, ⁠https://my.clevelandclinic.org/health/body/22134-colon-large-intestine⁠. Accessed 26 Nov. 2024.

2. National Cancer Institute. "Definition of Colon." NCI Dictionary of Cancer Terms, ⁠https://www.cancer.gov/publications/dictionaries/cancer-terms/def/colon⁠. Accessed 26 Nov. 2024.

3. Mayo Clinic. "Colon Cancer: Symptoms and Causes." Mayo Clinic, ⁠https://www.mayoclinic.org/diseases-conditions/colon-cancer/symptoms-causes/syc-20353669⁠. Accessed 26 Nov. 2024.

4. National Cancer Institute. "Rectal Cancer Treatment (PDQ®)–Patient Version." NCI, ⁠https://www.cancer.gov/types/colorectal/patient/rectal-treatment-pdq⁠. Accessed 26 Nov. 2024.

5. National Institute of Diabetes and Digestive and Kidney Diseases. "Your Digestive System & How It Works." NIDDK, ⁠https://www.niddk.nih.gov/health-information/digestive-diseases/digestive-system-how-it-works⁠. Accessed 26 Nov. 2024.

6. Cleveland Clinic. "Salivary Glands." Cleveland Clinic, ⁠https://my.clevelandclinic.org/health/body/23462-salivary-glands⁠. Accessed 26 Nov. 2024.

7. Chaudhry, Syed R., and Bruno Bordoni. "Anatomy, Thorax, Esophagus." StatPearls [Internet], StatPearls Publishing, 2024, ⁠https://www.ncbi.nlm.nih.gov/books/NBK482513/⁠. Accessed 26 Nov. 2024.

8. Colorectal Cancer Alliance. "Facts and Statistics about Colorectal Cancer." Colorectal Cancer Alliance, ⁠https://colorectalcancer.org/basics/facts-and-statistics⁠. Accessed 26 Nov. 2024.

9. Czinn, Steven J., and Samra Sarigol Blanchard. "Developmental Anatomy and Physiology of the Stomach." Pediatric Gastrointestinal and Liver Disease, 4th ed., Elsevier, 2011.

10. Peyrot des Gachons, Catherine, and Paul A. S. Breslin. "Salivary Amylase: Digestion and Metabolic Syndrome." Current Diabetes Reports, vol. 16, no. 10, 2016, p. 102. Springer, https://doi.org/10.1007/s11892-016-0794-7.

11. Center for Disease Control and Prevention. "Screening for Colorectal Cancer." CDC, ⁠https://www.cdc.gov/colorectal-cancer/screening/index.html⁠. Accessed 26 Nov. 2024.

12. Moraes, Gilberto, and Luciana Cristina de Almeida. "Nutrition and Functional Aspects of Digestion in Fish." Biology and Physiology of Freshwater Neotropical Fish, Elsevier, 2020.

13. National Cancer Institute. "Definition of Small Intestine." NCI Dictionary of Cancer Terms, ⁠https://www.cancer.gov/publications/dictionaries/cancer-terms/def/small-intestine⁠. Accessed 26 Nov. 2024.

14. Rodrigues, Victor F., et al. "Akkermansia Muciniphila and Gut Immune System: A Good Friendship That Attenuates Inflammatory Bowel Disease, Obesity, and Diabetes." Frontiers in Immunology, vol. 13, 2022, p. 934695, https://doi.org/10.3389/fimmu.2022.934695.

15. National Library of Medicine. "Colorectal Cancer Statistics." PubMed Central, ⁠https://pmc.ncbi.nlm.nih.gov/articles/PMC5785537⁠. Accessed 26 Nov. 2024.