Inside: What is SIBO (Small Intestinal Bacterial Overgrowth); How to test and How does it contribute to chronic fatigue. 5 ways research shows SIBO contributes to Fatigue.
Small intestinal bacterial overgrowth ( SIBO ) is such a common condition but often underdiagnosed. There are good and bad bacteria in our gut but there has to be a balance between the good and the bad bacteria.
Majority of your bacteria should stay in the large colon but in SIBO there is an overgrowth of bacteria especially in the small intestine.
With the advantage of easy testing now most people can be easily tested but most physicians are ignorant about this condition.
How to Test SIBO?
The SIBO test that you should be getting is called Lactulose Breath test to correctly identify if you have SIBO or not.
One of the most common symptoms that people have with SIBO is fatigue, brain fog, dizziness and it is one of the important causes of chronic fatigue now. Most people associate gut symptoms like constipation, diarrhoea, bloating, gas, abdominal pain with SIBO but not fatigue.
But now we have research which supports that people with chronic fatigue syndrome have more chances of SIBO and gut dysfunction.
Why SIBO Can Cause Fatigue.
Now the bigger question is — How does SIBO cause fatigue?
SIBO which is basically an overgrowth of bacteria in the small intestine can impair digestion and absorption of several nutrients and can thus contribute to the fatigue even after eating food.
Here are 5 Research-Backed ways SIBO contributes to chronic Fatigue
Vitamin B12 deficiency:
We all know that vitamin B12 deficiency can cause fatigue in people and SIBO can be the reason behind B12 deficiency. In SIBO as there is an overgrowth of bacteria, this bacteria actually use B12 from the food and you don’t have much available to absorb. Also, the overgrown bacteria binds to B12 and interferes with its absorption. Because of both these reasons SIBO causes B12 deficiency [ 1,2 ] and contribute to fatigue.
The excessive bacterial overgrowth leads to deconjugation of bile acids in your gut. Now bile acids are part of your bile which is produced by the liver and stored in the gallbladder. Bile is important for fat digestion and absorption. So with this bile acid deconjugation and impaired absorption, it ultimately leads to malabsorption of fats [3,4].
Now good fatty acids are building blocks of our cells and also important for energy production. So the impaired fatty acid absorption contributes to our fatigue even more.
Fat-soluble Vitamin deficiency
There are several fat-soluble vitamins, and they are absorbed in your intestine with the help of bile acids. So with impaired absorption of bile acids because of SIBO the fat-soluble vitamins are also not absorbed properly [4,5]. The fat-soluble vitamins are vitamin A, D, E, K. Deficiency of these vitamins also contributes to fatigue.
There is also impaired absorption of amino acids in the intestinal lumen because of SIBO. This is because of the inactivation of pancreatic enzymes which helps with the uptake of amino acids . Proteins are the building blocks and if they are low that also causes issues with fatigue too.
So as you see the SIBO fatigue is real and there is an underlying reason for it. SIBO causes not only gut symptoms but also causes malabsorption issues.
The excessive bacteria interfere with the digestion of not only carbohydrates but also proteins and fats which are very important for the normal functioning of your body.
Deficiency of several vitamins is also seen in cases of SIBO specially Vitamin B12 which makes the fatigue worse. Other fat-soluble vitamins like A, D, E, K which are also mal-absorbed contributes to this SIBO fatigue too. So treating SIBO is not only important from the gut perspective but is also important for your overall health. And we do see improvement in patients fatigue after the treatment of SIBO.
- Bohm, M., Siwiec, R. M., & Wo, J. M. (2013). Diagnosis and management of small intestinal bacterial overgrowth. Nutrition in Clinical Practice, 28(3), 289–299. doi:10.1177/0884533613485882
- Festen, H. P. (1991). Intrinsic factor secretion and cobalamin absorption: Physiology and pathophysiology in the gastrointestinal tract. Scandinavian Journal of Gastroenterology, 26(Suppl. 188), 1–7. doi:10.3109/00365529109111222
- Quigley, E. M., & Quera, R. (2006). Small intestinal bacterial overgrowth: Roles of antibiotics, prebiotics, and probiotics. Gastroenterology, 130(2). doi:10.1053/j.gastro.2005.11.046
- Smith, B. S., & Summa, M. A. (1999). Does omeprazole cause fat malabsorption? Nutrition in Clinical Care, 2(2), 103–108. doi:10. 1046/j.1523-5408.1999.00091.x
- Parodi, A., Lauritano, E., Nardone, G., Fontana, L., Savarino, V., & Gasbarrini, A. (2009). Small intestinal bacterial overgrowth. Digestive and Liver Disease Sup
- Burke, V., Gracey, M., Thomas, J., & Malajczuk, A. (1975). Inhibition of intestinal amino acid absorption by unconjugated bile salt in vivo. Australian and New Zealand Journal of Medicine, 5(5), 430–432. doi:10.1111/j.1445-5994.1975.tb03051.x
- Rasmussen, Jamie MS Management of Small Intestinal Bacterial Overgrowth in Adult Patients.Gastroenterol Nurs. 2019 May/Jun;42(3):269-276. doi: 10.1097/SGA.0000000000000369