Fructo-Oligosaccharides

About

What it is and where it shows up.

Fructo-oligosaccharides (FOS) are naturally occurring short-chain carbohydrates composed of fructose units linked to a terminal glucose, found in plants such as chicory, onion, and banana, and also produced commercially from sucrose or inulin hydrolysis. They are used as prebiotic dietary fiber ingredients in foods, beverages, and infant formula to selectively stimulate the growth of beneficial gut bacteria such as bifidobacteria.

Safety summary

The regulatory and scientific consensus.

FOS has a strong safety profile and no formal Acceptable Daily Intake (ADI) has been established by international regulatory bodies, as it is classified as a food ingredient rather than a food additive. At doses above approximately 10 g/day in adults, FOS can cause dose-dependent gastrointestinal side effects including bloating, flatulence, cramping, and loose stools. Individuals with irritable bowel syndrome (IBS) may be particularly sensitive due to FOS's classification as a high-FODMAP (fermentable oligosaccharide) carbohydrate.

Regulatory landscape

What food-safety regulators have decided.

Jurisdiction	Status	Note
EFSA (European Food Safety Authority) (European Union)	Approved	Permitted as a dietary fiber and prebiotic food ingredient; not assigned an E number as it is not classified as a food additive under Regulation (EC) No 1333/2008. Permitted in infant formula in combined GOS/FOS formulations (up to 0.8 g FOS/L) under Regulation (EU) No 609/2013. EFSA NDA Panel evaluated multiple health claims for FOS related to bowel function, gut microbiota, SCFA production, and mineral absorption.source
FSSAI (Food Safety and Standards Authority of India) (India)	Approved	Approved for use in infant formula products containing galacto-oligosaccharides and fructo-oligosaccharides (e.g., FSSAI product approvals 75/Std/PA/FSSAI/2018 and 63/Std/PA/FSSAI/2020). Regulated under FSS (Health Supplements, Nutraceuticals, Food for Special Dietary Use, Functional Food and Novel Food) Regulations, 2016 and the Infant Formula Regulations (IFR) Version-II (2024).source
FDA (Food and Drug Administration) (United States)	Approved	GRAS status supported by multiple GRAS Notices: GRN 605 (fructo-oligosaccharides), GRN 623 (fructooligosaccharides), and GRN 1006 (short-chain FOS). Approved for use in a wide range of conventional foods and infant formula with no established maximum use level beyond GMP.source

Who should approach with care

Whose guidance would steer them away.

Ibs — FOS is a high-FODMAP fermentable oligosaccharide that is rapidly fermented in the colon, and its consumption can exacerbate hallmark IBS symptoms such as bloating, abdominal pain, and altered bowel habits in sensitive individuals.

Ibd — While prebiotic effects may be beneficial in remission phases of IBD, the fermentable nature of FOS can provoke gastrointestinal discomfort or trigger flares in active disease; use should be guided by a clinician.

Infants — FOS is permitted in infant formula only at regulated levels (e.g., up to 0.8 g FOS/L as part of approved GOS/FOS blends in the EU under Regulation (EU) No 609/2013 and under FSSAI-approved products in India); amounts above approved limits are not established as safe for infants.

Research citations

The sources behind this verdict.

1FDA. GRAS Notice 605: Fructo-oligosaccharides. fda.gov
2FSSAI. List of product(s)/ingredient(s) applications Approved under Food Safety and Standards (NSF & FI) Regulations, 2017 — as on 2nd May 2025, 2025. fssai.gov.in
3FDA. GRAS Notice 1006: Short-chain Fructooligosaccharides, 2021. fda.gov
4EFSA. Short-chain fructooligosaccharides from sucrose and maintenance of normal defecation: evaluation of a health claim pursuant to Article 13(5) of Regulation (EC) No 1924/2006 — EFSA NDA Panel, EFSA Journal 2016, 2016. efsa.europa.eu
5EFSA. Scientific Opinion on the substantiation of health claims related to fructooligosaccharides (FOS) from sucrose — EFSA NDA Panel, EFSA Journal 2011;9(4):2023, 2011. efsa.europa.eu

Independently researched5 citations