Feed the gut with prebiotics

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Our knowledge and recognition of the gut microbiome continues to evolve as science draws more and more connections between the gut and other organs such as the brain, heart, and skin. While the beneficial bacteria known as probiotics are the most recognized aspect of the microbiome space, the science behind prebiotics is getting more sophisticated and may offer a compelling narrative to consumers.

“Probiotics certainly paved the way for the rest of the ‘biotics.’ The biotics industry wouldn’t be where it is today without the sound research, consumer education, and hard work performed by the probiotic leaders,” explains Cara Kennedy, director of marketing for Solnul (Carberry, Manitoba, Canada). “Consumers’ understanding of probiotics has helped connect the concept of prebiotics, food for probiotics and other healthy bacteria in the gut, bridging the knowledge gap. Some prebiotics also have the added benefit of being dietary fiber, which consumers can comprehend.”

According to the International Scientific Association of Probiotics and Prebiotics (ISAPP), prebiotics are defined as “a selectively fermented ingredient that results in specific changes in the composition and/or activity of the gastrointestinal microbiota, thus conferring benefit(s) upon host health.”1 The selective fermentation aspect is a particularly compelling factor given that we all have a unique microbiota. As Kennedy mentions, prebiotics are food for the bacteria in our microbiome helping to maintain and improve our natural microbial composition. This differs from the idea of adding bacteria in the form of probiotic supplements. Both are valid strategies, but schools of thought may differ.

Kathy Lund from AIDP (City of Industry, CA), for example, sees a lot more value in prebiotic supplementation. “Our philosophy that has driven us in the prebiotic space is that we believe that [prebiotic supplementation] is the better thing [to do] for your microbiome,” says Lund. This is because probiotics taken as supplements may not be compatible with the bacteria in your microbiome, she explains. Prebiotics on the other hand, says Lund, feed the bacteria unique to your microbiome. AIDP for its part distributes a number of different prebiotic ingredients, each of which have their own particular benefits.

Just like specific probiotic strains can influence different health outcomes, prebiotics are selectively fermented by specific bacteria. For example, fructans, such as inulin and fructo-oligosaccharide (FOS) are selectively fermented by lactic acid bacteria while galacto-oligosaccharides (GOS) are known to stimulate Bifidobacteria and Lactobacilli, as well as Enterobacteria, Bacteroidetes, and Firmicutes, to a lesser extent.1 Additionally, resistant starches are known to produce the short chain fatty acid, butyrate, and incorporated by various groups of Firmicutes.

In addition to feeding people’s specific microbiome, prebiotics also have the ability to modify an imbalanced microbial environment. The products of fermenting prebiotics are mostly acids which help decrease the pH of the gut. Research shows that altering the gut’s pH by as little as one unit, from 6.5 to 5.5 for example, contributes to changing the composition and population of the gut microbiota by decreasing acid-sensitive bacteria such as Bacteroides and promoting buryrate-forming bacteria such as Firmicutes.¹

In people dealing with inflammatory bowel diseases (IBD) such as irritable bowel syndrome and Crohn’s disease, they typically have microbiome that have less Bifidobacteria and Faecalibacterium prausnitzii and a decrease in the ratio of Bacteroides to Firmicutes, meaning that there is too little Firmicutes and too many Bacteroides. Too extreme in the reverse (ie., too many Firmicutes, too little Bacteroides) has been associated with obesity.² There is some conflicting evidence about the impact of prebiotics on IBD, but one study did find that a FOS formulation administered at 15 grams per day did increase Bifidobacteria and alleviate symptoms of Crohn’s disease. While not all research finds symptom relief from prebiotic administration, the alteration of the gut microbiome is an important aspect to consider.¹

Another study of a xylo-oligosaccharide from AIDP, called PreticX, found that administration of the XOS product at 2.8 grams per day significantly increased Bifidobacterium in participants.³ No increases in Lactobacillus were observed. The researchers explain that microbiomes high in Lactobacillus and low in Bifidobacterium have been associated with obesity. This is similar to the relationship between Firmicutes and Bacteroides. That study also saw a significant increase in Bacteroides fragilis (a member of Bacteroidetes), showing potential benefits in modulating the microbiome of overweight individuals.

Another study found that consumption of the XOS product at doses of 2 grams per day for 8 weeks significantly shifted the microbiome of prediabetic patients, decreasing or reversing the abundance of the genera Enterorhabdus, Howardella, and Slackia while increasing the abundance of Blautia hydrogenotrophica.⁴ This has the potential to reduce the risk of developing type II diabetes in prediabetics, say the researchers.

Research also shows that resistant starches such as Solnul’s resistant potato starch increased the abundance of Bifidobacterium and Akkermansia, which was found to reduce diarrhea and constipation in study participants.⁵ This same prebiotic was also found to support histamine sensitivity by reducing histamine levels and histamine-secreting bacteria, as well as positively impacting intestinal permeability.⁶ A resistant maltodextrin from ADM, called Fibersol, has been shown to increase Bifidobacterium as well.⁷ It’s also marketed for weight management, which you can read more about on page 18.

The health benefits of prebiotic supplementation can vary. We’ve already covered gut health, blood sugar support, histamine sensitivity, and weight management, but other potential benefits include immune health support, brain health, cardiovascular health, and even skin health.1 The body of scientific literature continues to grow.

In some jurisdiction, prebiotics may even carry certain claims. For example, in Europe, inulin and oligosaccharides from chicory root can carry claims of improving blood sugar levels. Some prebiotics, such as Solnul and Fibersol, are also making their way into FODMAP-friendly foods for people with inflammatory bowel diseases. Given that prebiotics are not live bacteria, they are often easier to formulate with compared to probiotics which may run into challenges with their stability at high temperatures, for example. Additionally, prebiotics are now being combined with probiotics in what are called synbiotic formulations. The logic behind this strategy is that the bacteria in the formulation can feed on the prebiotic and populate the gut more effectively. The potential of the category is immense, and innovation continues to result in effective and easy-to-work-with products.

References

1. Danavani-Davari, D.; Negahdaripour, M.; Karmzadeh,I.; Seifan, M.; Mohkam, M.; Masoumi, S.J.; Berenjian, A.; Ghasemi, Y.Prebiotics: Definition, Types, Sources, Mechanisms, and Clinical Applications. Foods. 2019, 8 (3), 92. DOI: 10.3390/foods8030092
2. Stojanov, S.; Berlec, A.; Štrukelj, B. The Influence of Probiotics on the Firmicutes/Bacteroidetes Ratio in the Treatment of Obesity and Inflammatory Bowel disease. Microorganisms. 2020, 8 (11), 1715. DOI: 10.3390/microorganisms8111715
3. Finegold, S.M.; Li, Z.; Summanen, P.H.; Downes, J.; Thames, G.; Corbett, K.; Dowd, S.; Krak, M.; Heber, D. Xylooligosaccharide increases bifidobacteria but not lactobacilli in human gut microbiota. Food & Function. 2014, 5 (3), 436-445.DOI: 10.1039/C3FO60348B
4. Yang, J.; Summanen, P.H.; Henning, S.M.; Hsu, M.; Lam, H.; Huang, J.; Tseng, C.H.; Dowd, S.E. et al. Xylooligosaccharide supplementation alters gut bacteria in both healthy and prediabetic adults: a pilot study. Front Physiol. 2015, 6, 216. DOI: 10.3389/fphys.2015.00216
5. Bush, J.R.; Baisley, J.; Harding, S.V.; Alfa, M.J. Consumption of Solnul™ Resistant Potato Starch Produces a Prebiotic Effect in a Randomized, Placebo-Controlled Clinical Trial. Nutrients. 2023, 15 (7), 1582. DOI: 10.3390/nu15071582
6. Bush, J.R.; Han, J.; Deehan, E.C.; Harding S.V.; Maiya, M.; Baisely, J.; Schibli, D.; Goodlett, D.R. Resistant potato starch supplementation reduces serum histamine levels in healthy adults with links to attenuated intestinal permeability. Journal of Functional Foods. 2023, 108, 105740. DOI: 10.1016/j.jff.2023.105740
7. Burns, A.M.; Solch, R.J.; Dennis-Wall, J.C.; Ukhanova, M.; Nieves, C.; Mai, V.; Gordon, D.T.; Langkamp-Henken, B. In healthy adults, resistant maltodextrin produces a greater change in fecal bifidobacteria counts and increases stool wet weight: a double-blind, randomized, controlled crossover study. Nurt Res. 2018, 60, 33-42. DOI: 10.1016/j.nutres.2018.09.007