Prebiotics primarily include soluble fibres which are not digested by the body. As these fibres pass into the large intestine undigested, the gut bacteria ferment these fibres and use them as fuel to grow. Fermentation results in release of short-chain fatty acids which are beneficial for health – i.e., they help improve gut health; fight chronic inflammation, boost immunity, and may also help with satiety and weight management (1).
Demand For Prebiotics
In recent years, the demand for prebiotics has grown. In August 2019, a report titled ‘Prebiotics Market Size, Share & Trends Analysis By Ingredients (FOS, Inulin, GOS, MOS), By Application (Food and Beverages, Dietary Supplements, Animal Feed), By Region, and Segment Forecasts, 2014 – 2024’ that can be found at the following link, determined that the global prebiotics market is projected to reach USD 8,794.7 MM by 2025 at a CAGR of 9.7%. The report attributed this increase to the growing emphasis on digestive health due to hectic lifestyles; and increased demand for functional food and dietary supplements.
Formulating With Prebiotics
From a food formulation stand-point, one usually thinks of inulin, fructo-oligosaccharides and galacto-oligosaccharides when you think of prebiotics. But honestly, formulating for prebiotics should not stop here. To help consumers beef up their prebiotic intakes and support growth of beneficial gut bacteria, it is also important to consider using a prebiotic food base or a combination of foods that offer prebiotic benefits. Research that looks at impact of a combination of different prebiotic food and prebiotic fibres on gut health, is essential for designing truly efficacious prebiotics foods.
Natural Sources of Prebiotics
Following are some prebiotic foods that you could consider adding into your prebiotic formulations:
Bananas contain small amounts of inulin; and green unripe bananas are rich in resistant starch, which is known to fuel growth of healthy bacteria (2). Daily intake of bananas resulted in a small increase in bifidobacteria levels; and reduced bloating (3).
Apples are rich in pectin fibre. Studies in rats have determined, that pectin promotes growth of healthy gut bacteria and decreases the growth of harmful bacteria (3).
Barley is rich in soluble fibres β-glucans. Researchers have determined that β-glucans from barley were able to improve the growth rate of beneficial bacteria in the gut, especially the L. plantarum species (4).
Oats are also rich in soluble fibre β-glucans. Researchers have determined that regular oatmeal porridge consumption resulted in a positive impact on gut microbiota (5). Additional research is needed to explore this benefit.
Pulses, especially beans, contain oligosaccharides which are not digested by gastric juices. These oligosaccharides are prebiotics which support growth of beneficial gut bacteria. For example, when 200g of chickpeas or 5g of oligosaccharide raffinose (fibre found in 200g of chickpeas) were consumed daily, researchers observed that both chickpeas and raffinose could modulate the intestinal microbial composition to promote intestinal health in humans (6). Pea fibre too was seen to feed lactobacilli and bifidobacteria (7).
Cocoa flavanols have been seen to promote the growth of beneficial bacteria in the gut (8).
Flaxseed contains both insoluble and soluble fibre. 2/3rd is insoluble fibre, and 1/3rd is soluble fibre. Soluble fibre in flaxseed has been observed to promote growth of healthy gut bacteria (9)
8. Elephant Yam
Elephant yam or konjac root contains glucomannan fibre, which promotes the growth of lactic acid bacteria in the large intestine (10).
The demand for prebiotic products that support gut health is definitely on the rise, as emerging microbiome research is highlighting the importance of maintaining gut health. Hence, it is imperative for the industry to study the impact of different food and prebiotic fibres on overall gut health, to assess whether it is symbiotic, and if it is beneficial, appropriate products should be launched in the marketplace.