Oligofructose and inulin as prebiotics in the gut
What it found
In people, animals and lab tests, oligofructose and inulin mostly increased bifidobacteria in the gut.
Some studies also found fewer harmful bacteria or softer stools.
What they found
Studies in people
Bifidobacteria increase
In several human studies, eating oligofructose or inulin raised levels of bifidobacteria in the stool. In one 45-day study of eight healthy men, 15 g per day of either ingredient made bifidobacteria the main bacteria in faeces.
Harmful bacteria decrease
In a 45-day study of eight healthy men, oligofructose lowered bacteroides, clostridia and fusobacteria. In a 19-day study of elderly constipated patients, inulin lowered enterococci and enterobacteria.
Dose and tolerance
In a 7-day study of forty healthy volunteers, 10 g per day of oligofructose increased bifidobacteria without significant side effects like flatulence. A 6 g per day dose of oligofructose had no effect on irritable bowel syndrome symptoms.
Stool frequency
In six healthy people with low stool frequency, 15 g per day of inulin increased stool frequency and faecal bulk. In elderly constipated patients, inulin had a better laxative effect than lactose.
Studies in people and animals
Lab and animal results
In lab tests with human faeces, oligofructose and inulin were fermented by bifidobacteria and lactobacilli. In rats, oligofructose increased lactic acid bacteria after 2 weeks, but this effect was lost by weeks 8 and 27.
Other findings
Food products
Oligofructose and inulin are used in drinks, yoghurts, biscuits and table spreads. They are classified as food or food ingredients in all countries where they are used.
What the authors conclude
“The prebiotic effects of inulin and oligofructose have been confirmed in numerous laboratory and human trials.”
Also in their conclusions
- They conclude that the prebiotic effects of inulin and oligofructose have been confirmed in numerous laboratory and human trials.
- They say new molecular methods will help determine health applications and explain how these ingredients work.
- They suggest that prebiotics which reach the far part of the colon could be useful, because that is where chronic diseases like colon cancer and ulcerative colitis start.
How it was done
The authors wanted to explain how non-digestible food ingredients like oligofructose can change the mix of bacteria in the large intestine towards a more helpful community.
They gathered results from many studies. These included lab tests with human faeces, animal studies, and human trials of different sizes and lengths, from 7 days to 45 days.
What it can’t tell you
- Many of the human studies were small and lasted only days or weeks, so they cannot show long-term effects.
- The studies used different doses and forms of oligofructose, so it is hard to compare them directly.
- Lab and animal results may not reflect what happens in people.
Who paid
- Authors work at
- The University of Reading, UK
The paper
- Title
- Prebiotic effects of inulin and oligofructose
- Type
- ReviewThe authors read earlier studies and describe what they found. It isn’t a new study.
- Evidence
- Studies in people · animals · lab
- Summarised from
- Full text
- Cite
- Kolida S, Tuohy K, Gibson GR (2002). Prebiotic effects of inulin and oligofructose. The British journal of nutrition. doi:10.1079/BJNBJN/2002537Free full textPubMed 12088518DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error