Do Polyps in the Colon start as Bacterial Biofilm?

Polyps in the Colon and Sinuses

A colon polyp is a small clump of cells that forms on the lining of the colon. Most colon polyps are harmless. But over time, some colon polyps can develop into colon cancer, which is often fatal when found in its later stages.

Polyps are abnormal growths rising from the lining of the large intestine (colon) that protrude into the intestinal canal (lumen). Most polyps are benign (noncancerous) and cause no symptoms. Most benign polyps are classified as one of two types: adenomatous (adenomas) and hyperplastic. Adenomatous polyps (adenomas) of the colon and rectum are benign (noncancerous) growths, but may be precursor lesions to colorectal cancer. Polyps greater than one centimeter in diameter are associated with a greater risk of cancer. If polyps are not removed, they continue to grow and can become cancerous.


Colon polyps often cause no symptoms. A person might not know they have a polyp until their doctor finds it during an examination of the bowel. But some people with colon polyps experience:

  • Rectal bleeding. This can be a sign of colon polyps or cancer or other conditions, such as hemorrhoids or minor tears in the anus.
  • Change in stool color. Blood can show up as red streaks in your stool or make stool appear black. This may be associated with internal or external hemorrhoid. An indicator of portal hypertension.
  • Change in bowel habits. Constipation or diarrhea that lasts longer than a week may indicate the presence of a large colon polyp. But a number of other conditions can also cause changes in bowel habits.
  • Pain, nausea or vomiting. A large colon polyp can partially obstruct the bowel, leading to crampy abdominal pain, nausea and vomiting.
  • Iron deficiency anemia.
    • Bleeding from polyps can occur when portal hypertension causes internal hemorrhoids. Chronic bleeding robs the body of the iron needed to produce the substance that allows red blood cells to carry oxygen to your body (hemoglobin). The result is iron deficiency anemia, which can make the patient feel tired and short of breath.
    • Anemia of Chronic Inflammation. As bacteria responsible for the formation of the biofilm/polyp. The numbers will increase their need for iron. When angiogenesis occurs with the polyp, ferophilic bacteria will have access to red blood cells. They will hemolyze the RBCs to support their needs.

Polyps are bacterial biofilm that have grown large colonies with multi-cultural species supporting size and maintenance of the polyp. Bacteria in the lumen are transient and may be more influenced by diet while the adherent mucosal bacteria are considered residents and may be more relevant to the formation of polyps because of their close contact with the host mucosa and immune cells. Bacteria communities in the feces differ from the mucosa.

PCR sequencing methods to characterize the adherent bacterial composition in normal rectal mucosal biopsies and observed that the gut bacterial composition of subjects with adenomas differed significantly from that of control subjects without adenomas.

Biofilm in the Colon

When healthy, the colon is covered by a mucus layer that segregates the microbiota from direct contact with the host colonic epithelium. Healthy colons are typically covered with a mucus layer devoid of bacteria.

Breaches of this protective mucus layer with resulting increased contact between mucosal microbiota and the colonic epithelial cells have been proposed as a critical first step in inciting changes in tissue biology and/or inflammation that yield inflammatory bowel disease.

Biofilms are defined as aggregations of microbial communities encased in a polymeric matrix that adhere to either biological or nonbiological surfaces. Biofilms that invade the colonic mucus layer and come into direct contact with mucosal epithelial cells indicate a pathologic state. Biofilms characterize numerous chronic mucosal disease states in and outside of the colon (including inflammatory bowel diseases, pharyngo-tonsillitis, otitis media, rhinosinusitis, urethritis, and vaginitis), where direct bacterial contact with epithelial cells results in perturbed epithelial function and chronic inflammation.