From a 2015 USDA technical report:

“Inulin is a naturally-occurring carbohydrate found in roots of chicory and many other food plants. Oligofructose is derived from inulin.

Inulin is a polymer chain of multiple fructose molecules with a glucose molecule at one end. Length of the fructose chain of inulin can range from 2–60 fructose molecules.

Inulin is mostly indigestible by human enzymes due to its shape, but is digestible by microbes in the large intestine. It can serve as a prebiotic, a nutrient source for microflora in the human digestive system.”

From a 2021 review Friend or foe? The roles of inulin-type fructans (not freely available):

“Inulin-type fructans are a mixture of inulin, oligofructose and fructooligosaccharide (FOS). They aren’t absorbed in the stomach and small intestine. They can be completely fermented by bacteria in the large intestine.

They treat digestive diseases, metabolic syndrome, immune system and inflammatory diseases, endothelial dysfunction, and prevent infection and cancer.

A 2010 gastrointestinal tolerance of chicory inulin products study indicated that 10 g/day of native inulin or 5 g/day of oligofructose were well-tolerated in healthy, young adults. Over this dose would induce mild gastrointestinal symptoms.”

I bought this last month:

From the manufacturer:

“A powdered food ingredient based on chicory inulin with a high level of oligofructose 1 (DP2-DP10). This product is characterized by a high solubility.

Inulin from chicory is a polydisperse mixture of linear fructose polymers with mostly a terminal glucose unit, coupled by means of beta (2-1) bonds. The number of units (degree of polymerization) can vary between 2 and 60.

It is a fine, white powder with 30% the sweetness of sucrose. It has >=85% inulin/oligofructose and <15% fructose, glucose, sucrose. It has 2.2 kcal/gram and a glycemic response of 20.”

From the vendor:

“You pay for the product… not the product packaging! Each teaspoon (tsp) delivers 2g fiber.

Inulin is hygroscopic so will take on moisture, especially in humid environments. Store in a dry place and remove as much air from the pouch as able before resealing after each use. Alternately, you could store in several smaller air-tight containers. This will limit exposure to possible humidity. Room temperature or cooler is ideal.”

It tastes like cotton candy. 🙂 Its first use was to replace 2 grams of soluble fiber I got from eating 56 grams of noodles:

Probably won’t reorder FOS when I run out. I’ve taken 1.5 grams FOS every day for 16 years.