The 7 benefits of short-chain FOS

The Short Chain Fructo-oligosaccharides (scFOS)

Rising trends in the use of prebiotics and their role in maintaining good health have been creating an extensive range of new product development prospects for food/beverages manufacturers. Since attention has drawn to this category over the past few years, consumption of prebiotics has gone up significantly, and it is now emerging as the “next super ingredient” for overall health.

Prebiotics and their types

After the introduction of the concept of “Prebiotics” in 1995, the International Scientific Association of Probiotics and Prebiotics (ISAPP) described dietary prebiotics as a selectively fermented ingredient that results in specific changes in the composition and activity of the gut bacteria, thus conferring benefits to the human body. ¹  Prebiotics has been shown to play a vital role in modulating the gut microbiome, increasing the production of short-chain fatty acids (SCFA), and reducing the risk of development of various diseases and managing health conditions such as irritable bowel syndrome, colon cancer, type 2 diabetes mellitus, and obesity, among many others. There are many types of prebiotics, the majority being carbohydrates that are oligosaccharides (a carbohydrate having three to 10 simple sugars units linked together), such as

• Fructans, which consist of Inulin and fructo-oligosaccharides 
• Galacto- oligosaccharides
• Glucose-derived oligosaccharides
• Other oligosaccharides

Among all of the above, the two best-known prebiotics are Inulin and FOS

Understanding scFOS and Inulin

Fructooligosaccharides (FOS) and Inulin occur naturally in various plants such as onions, jerusalem artichokes, chicory, asparagus, leeks, and garlic. They are a mix of fructose units held together by β-(2→1)-glycosidic bonds with a terminal glucose unit.

• Inulin, mainly extracted from chicory roots, has a longer chain length, with 10 to 60 fructose molecules.
• Oligofructose/FOS has a shorter chain length of 2 to 10 fructose molecules.
• The shorter chain FOS with less than 5 fructose molecules is called scFOS. FOSSENCETM from Tata NQ is scFOS.  (Figure 1)².

scFOS and Inulin: Functional benefits

The colonic microflora ferments Inulin and scFOS to produce short-chain fatty acids (SCFA) and gases (CO2, H2, methane). Both exhibit their beneficial effects through selective stimulation of growth and activity of good bacteria (e.g. Bifidobacterium and lactobacilli) in the colon, thus improving human health. 

Yet, there are many differences between scFOS and Inulin, which are summarized in Table 1.

1. Fermentation site

ScFOS are fermented in the proximal colon (initial part of the colon) and Inulin in the distal colon (later part of the colon). scFOS are rapidly fermented when compared to the longer chain forms ³ , resulting in faster growth of bifidobacteria and consequently increased synthesis of SCFA. ⁴ Longer chain molecules shall be fermented in the distal colon and thus may be delayed the growth of beneficial bacteria and synthesis of SCFAs. Therefore, for steady bacterial growth and metabolite production, a combination of scFOS and Inulin could be an appropriate measure to support human health by an overall good bacterial growth.

2. Prebiotic Index (PI) of scFOS and Inulin

Prebiotic Index (PI) is “the increase in the absolute number of bifidobacteria expressed divided by the daily dose of prebiotic ingested”. A higher PI indicates a better growth of good bacteria in the gut. In an in-vitro study ⁵ , the PI of FOS at 24 hours was approximately 2.5, whereas that for Inulin was 1. It was also seen that partial replacement of Inulin with scFOS could provide an

improvement in the PI as compared to PI of Inulin alone, as seen in figure 2. An in-vitro study also showed that the bifidobacteria growth was higher with scFOS than the high-performance Inulin at 24hrs (Figure 2). ⁶

3. Short-Chain Fatty Acid Production (SCFA)

Both scFOS and inulin fibres are not digested/metabolized in the digestive tract and are fermented in the colon. The colonic fermentation of the two fibres leads to the production of SCFA (butyrate, acetate, and propionate), which are known to have varied health benefits. SCFA are produced quickly with scFOS compared to their long chain counterparts as they are metabolized earlier in the proximal colon. A study reported that the scFOS are rapidly fermented by microbes in the colon and have better effects on the growth of bifidobacteria when compared to Inulin and sucrose. ^7, 8 , In an in-vitro study, scFOS showed better bifidobacteria growth than the high performance inulin at 24hrs ⁹ (Figure 3)

4. Gut pH reduction

All prebiotic fibres lead to increase in SCFAs that in turn result in decreased pH, indirectly influencing the colonic microflora composition. Table 2 below shares that scFOS could be better than other fructans in gut pH reduction ¹⁰ , thus leading to improved gut health benefits^{11 12 13 14}

5. Glycemic Effect

It is known that scFOS is a soluble fibre and a non-available carbohydrate that is low in calories. It is sweet to taste and may be a replacer for sugar in food applications. Replacing sugars would help in reducing the available carbohydrates and thus not only lower the total energy intake, but also support post prandial glucose reduction. Four clinical studies have shown improvement in glycaemia with scFOS. ^{15, 16, 17, 18} Study on Fossence® showed that when consumed alone, Fossence® does not increase postprandial glucose and insulin levels, indicating it is resistant to breakdown. (Figure 4) When added to a carbohydrate load, no increase in postprandial glucose or insulin levels is observed, while substitution of 30% of glycemic carbohydrate by Fossence® significantly decreased postprandial glucose and insulin levels ¹⁹ . Thus, a partial replacement of Inulin with scFOS will have similar glycemic effects along with the additional benefits like added sweetness.

6. Gas Production

Due to the colonic fermentation of prebiotics, there is a production of gases that may lead to gastric intolerance. Ghoddusi et al. 2007 have shown that the total gas volume production with scFOS in 32hrs was found to be lower than Inulin, isomalt and polydextrose. Moreover, when scFOS was combined with Inulin and or other long-chain fibres, an additional gain was observed on the reduction of discomfort due to excessive gas production (Figure 5) ²⁰ .

7. Taste and Calorie Content

scFOS is sweeter than Inulin, and hence, sugar replacement can be done without compromising the sweetness in a food product. In general, scFOS/FOS and Inulin are used for flavour and mouthfeel enhancement, respectively.

Summary

Fructans like the scFOS have nutritional and functional attributes compared to Inulin and can be added to different food applications without compromising its benefits. It can be conveniently added alone or in combination with inulin in applications as biscuits and cakes, breakfast cereals and cereal-filled bars, ice, and dessert, dairy products, yogurt, and milk. The inclusion of scFOS in food applications may be additionally beneficial for energy-conscious food concepts without compromising the sweetness of the product.

References

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