Do prebiotics modulate specific gut microbes?

The human microbiome is a complicated ecosystem with a fundamental role in preserving intestinal functionality and overall bodily health (Satokari, 2019). The gastrointestinal tract is full of these microbiome microorganisms (Markowiak, & Śliżewska, 2017). They are commensal and have a symbiotic co-evolution with their human host. They produce nutrients, prevent infections caused by intestinal pathogens, and modulate a normal immunological response for their host. The introduction of probiotics, prebiotics, or synbiotics into the human diet is beneficial to these intestinal flora.  Evidence suggests a combination of prebiotics and probiotics as a symbiotic have immune-modulatory abilities (Hardy et al., 2013). Examples of these food forms are raw vegetables and fruit, fermented foods, dairy products, pharmaceutical formulas, and functional food (Markowiak, & Śliżewska, 2017). 

Diet can change the gut microbiome (Hasan & Yang, 2019). In this review, they looked at how the host shapes its gut microbiota with nutritional factors such as prebiotics, & probiotics  (Hasan & Yang, 2019). During breastfeeding the composition of the breast milk affects the shaping of the early gut microbiome (Hasan & Yang, 2019). Human milk microbiota play important roles in immune-related activities like increasing plasma cells in the intestines to produce IgA, stimulation of cytotoxic Th1 cells, cytokines that balance the microenvironment, and development of a systemic immune system. Vegetarian diets are connected with a healthy, diverse gut with species that metabolize insoluble carbohydrates, like Ruminococcus, Roseburia, and Eubacterium. Non-vegetarian diet (Western diet) has a decreasing amount of Firmicutes and an increase in Bacteroides. After eating a Western diet, the gut microbiome ferments amino acids resulting in the creation of short-chain fatty acids to use as energy, as well as more harmful compounds. The vegetarian diet inhibits this production, and promotes carbohydrate fermentation in the gut microbiome.

Prebiotics affect the microorganisms already in the colon. Prebiotics (indigestible dietary fiber) offer a health benefit to the host making products through anaerobic fermentation (Hardy et al., 2013). They mainly target Lactobacilli and Bifidobacteria and increase the production of short-chain fatty acids and lower pH (Hasan & Yang, 2019). Dietary fiber maintains the integrity of the mucosal barrier in the gut. Inulin can prevent the harmful effects of high-fat diets on the mucus layer and metabolism. Low-fiber diets cause weakening in the colonic mucus barrier leading to microbiota crept from pathogen susceptibility and inflammation (Hasan & Yang, 2019). The combination of galacto-oligosaccharides and fructo-oligosaccharides promote Bifidobacteria and reduce Clostridium in the gut. Galacto-oligosaccharides increase Lactobacillus. Arabino-xylooligosaccharides and inulin change the intestinal barrier function and immune response (Hasan & Yang, 2019).

The fact that different foods and dietary lifestyles can have such an impact on the microbiome and ultimately our health is astounding. The gut microbiota is an organ that co-develops with us throughout our lives and it is evident that certain prebiotics, probiotics, synbiotics can shape the composition of the gut microbiota and its metabolic activities to promote health and/or prevent diseases (Umu, Rudi, & Diep, 2017). This offers possibilities for healing the gut with certain foods and diets that can be implemented indefinitely every single day. 

References

Hardy, H., Harris, J., Lyon, E., Beal, J., & Foey, A. D. (2013). Probiotics, Prebiotics and Immunomodulation of Gut Mucosal Defences: Homeostasis and Immunopathology. Nutrients, 5(6), 1869–1912. https://doi.org/10.3390/nu5061869

Hasan, N., & Yang, H. (2019). Factors affecting the composition of the gut microbiota, and its modulation. PeerJ, 7. https://doi.org/10.7717/peerj.7502

Markowiak, P., & Śliżewska, K. (2017). Effects of Probiotics, Prebiotics, and Synbiotics on Human Health. Nutrients, 9(9). https://doi.org/10.3390/nu9091021

Satokari, R. (2019). Modulation of Gut Microbiota for Health by Current and Next-Generation Probiotics. Nutrients, 11(8). https://doi.org/10.3390/nu11081921

Umu, Ö. C. O., Rudi, K., & Diep, D. B. (2017). Modulation of the gut microbiota by prebiotic fibres and bacteriocins. Microbial Ecology in Health and Disease, 28(1). https://doi.org/10.1080/16512235.2017.1348886