Fructo-oligosaccharides (FOS)


Fructo-oligosaccharides (FOS) are sugars found in food items like bananas, asparagus, and garlic. FOS have been used to ease digestion and regulate bacteria. They are often taken with probiotics. FOS can be taken as a pill or powder.


4 to 6 grams daily

What Research Shows

May Not Be Effective

Not Enough Data to Assess

  • Bowel disorders A1

Editorial process and description of evidence categories can be found at EBSCO NAT Editorial Process.

Safety Notes

It is likely safe to take FOS in small doses for a short time, but belly pain may happen. Not enough studies have been done to say whether it is safe to use for a long period or by women who are pregnant or breastfeeding.


Talk to your doctor about any supplements or therapy you would like to use. Some can interfere with treatment or make conditions worse.


A. Bowel Disorders

A1. Paineau D, Payen F, et al. The effects of regular consumption of short-chain fructo-oligosaccharides on digestive comfort of subjects with minor functional bowel disorders. Br J Nutr. 2008;99(2):311-318.

B. Crohn Disease

B1. Benjamin JL, Hedin CR, et al. Randomised, double-blind, placebo-controlled trial of fructo oligosaccharides in active Crohn's disease. Gut. 2011 Jul;60(7):923-929.

Last reviewed July 2019 by EBSCO NAT Review Board Eric Hurwitz, DC
Last Updated: 5/6/2020

EBSCO Information Services is fully accredited by URAC. URAC is an independent, nonprofit health care accrediting organization dedicated to promoting health care quality through accreditation, certification and commendation.

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.

To send comments or feedback to our Editorial Team regarding the content please email us at Our Health Library Support team will respond to your email request within 2 business days.