Sugar linked to gut bacteria overgrowth

Posted on Mon, 1 Feb 16

A diet high in added sugars, refined carbohydrates and low in fiber has been linked to small intestinal bacterial overgrowth (SIBO), a condition associated with abdominal pain and thought to play a role in the development of a diverse range of illness beyond the digestive system.

An imbalance in gut bacteria, referred to as dysbiosis, is emerging as an important factor in the development of a wide range of illness, from digestive symptoms such as bloating and pain, to fatty liver disease, type 2 diabetes, heart disease and weight gain.
 
SIBO is a condition in which gut bacteria which normally reside predominately in the large intestine overgrow into the small intestine where they can cause over fermentation, maldigestion and production of toxic products.
 
Some of the main treatment approaches for SIBO are specific anti-biotics, herbal medicines and probiotics, but understanding why the SIBO is there in the first place is perhaps more important than trying to eradicate it with anti-microbials as it could simply re-occur.
 
A group of researchers recently decided to see if there was a correlation between the foods people eat and SIBO, their hunch was that sugars and refined carbohydrates might be linked to bacterial overgrowth because sugars are fast-food for bacteria and could be used as fuel in the small intestine. Complex carbohydrates such as fruits, vegetables, whole grains and legumes, on the other hand, are not typically used by bacteria until they pass the small intestine and reach the large bowel.
 
By looking at SIBO prevalence in a group of obese people, lean people and analyzing their diets they found that obese people with SIBO ate a lot more carbohydrates, more refined sugars and less total and insoluble fibers when compared to healthy controls.

“Carbohydrates might promote the development of SIBO in obesity and fibers provide a protective function,” concluded the study investigators. “Our results suggest a close relationship between diet and SIBO in obesity, thus supporting a possible role for intestinal microbiota.”

Reference:

Ierardi E, Losurdo G, Sorrentino C, et al. Macronutrient intakes in obese subjects with or without small intestinal bacterial overgrowth: an alimentary survey. Scand J Gastroenterol. 2016 Mar;51(3):277-80.