GASTROENTEROLOGY ARTICLE OF THE WEEK
March 30, 2006
Dibaise JK, Young RJ, Vanderhoof JA. Enteric microbial flora, bacterial overgrowth and short bowel syndrome. Clin Gastroenterol Hepatol 2006;4:11-20
1. Barriers to bacterial overgrowth include
a. immunoglobulins in the salivary secretions
b. gastric acid
c. normal motility
d. intestinal mucus
e. pancreatico-biliary secretions
f. the ileocecal valve, which is the most important mechanism controlling bowel
flora in the small bowel.
2. Beneficial effects of gut flora include
a. break down of bile salts in the small bowel
b. maintenance of gut epithelium turnover and overall thickness
c. production of micronutrients such as vitamin K and folate
d. fermentation of unabsorbed carbohydrates to a usable caloric source
e. preventing gut flora colonization with pathogens.
3. Mechanisms leading to diarrhea in SIBO include
a. destruction of the intestinal villi by production of toxic substances
b. development of celiac sprue
c. development of lactose maldigestion
d. bacterial deconjugation of bile leading to steatorrhea
e. increased production of VIP
f. secretory diarrhea from deconjugated bile acids and hydroxylated fatty acids
g. flattening of the villi with resultant malabsorption.
True or False
4. The area of the GI tract with the highest concentrations of bacteria is in the distal small intestine and colon.
5. Proximal to the terminal ileum, aerobic organisms predominate, distally the flora changes to anaerobic organisms with colony counts of 1010 to 1012 in the colon.
6. The deleterious effects noted in SIBO are usually caused by overgrowth of anaerobic organisms.
7. Jaundice may be a consequence of SIBO in patients with SBS, particularly when caused by gram negative organisms.
8. Breath tests are usually not reliable for diagnosing SIBO in patients with SBS
9. D-lactic acidosis may be a complication of short bowel syndrome, which only occurs in patients who have a colon.
10. SIBO may cause uric acid kidney stone formation
11. SIBO may cause a decrease number of Farmer’s cells (also known as cells of Cajal)
12. Large joint arthralgia may be a manifestation of SIBO