Probiotics, prebiotics, and postbiotics in health and disease

Abstract

The gut microbiota and its homeostasis play a crucial role in human health. However, for some diseases related to the gut microbiota, current traditional medicines can only relieve symptoms, and it is difficult to solve the root causes or even cause side effects like disturbances in the gut microbiota. Increasing clinical studies and evidences have demonstrated that probiotics, prebiotics, and postbiotics can prevent and treat various diseases, but currently they can only be used as dietary supplements rather than medicines, which restricts the application of probiotics in the field of medicine. Here, this review analyzes the importance of gut microbiota in human health and the current problems of traditional medicines, and systematically summarizes the effectiveness and mechanisms of probiotics, prebiotics, and postbiotics in maintaining health and treating diseases based on animal models and clinical trials. And based on current research outcomes and development trends in this field, the challenges and prospects of their clinical application in maintaining health, alleviating and treating diseases are analyzed. It is hoped to promote the application of probiotics, prebiotics, and postbiotics in disease treatment and open up new frontiers in probiotic research.

Keywords: clinical trials; gut microbiota; postbiotics; prebiotics; probiotics.

FIGURE 1

Diseases associated with gut microbiota dysbiosis, and probiotics, prebiotics, and postbiotics to alleviate or treat disease by restoring gut microbiota homeostasis.

FIGURE 2

History of the development of probiotics, prebiotics, and postbiotics. FAO, Food and Agriculture Organization of the United Nations; WHO, World Health Organization; ISAPP, International Scientific Association for Probiotics and Prebiotics.

FIGURE 3

Trends in clinical trials of probiotics since the 21st century. (A) Annual number of clinical trials and phases 1−4 of clinical trials of probiotics registered in the ClinicalTrials.gov database, and the growth fitting model of the total number of clinical trials (2001–2022), (B) and the main ones that scientists are interested in disease type. CRC, colorectal cancer; IBS, irritable bowel syndrome; IBD, inflammatory bowel disease. Data from https://clinicaltrials.gov/.

FIGURE 4

Primary therapeutic mechanisms of probiotics and postbiotics. (A) Production of antimicrobial substances. (B) Regulation of gut microbiome balance. (C) Increased adhesion to the intestinal mucosa and improvement of the epithelial barrier. (D) Stimulation of the immune system. (E) Affects the gut–brain axis, gut–kidney axis, and gut–liver axis. (F) Degradation or absorption the detrimental metabolites produced by metabolic diseases or harmful exogenous substances and metabolizes prebiotics to produce beneficial substances. (G) Competitive exclusion of pathogenic microorganisms.

FIGURE 5

The main mechanisms of prebiotics to maintain health and treat diseases. (A) Promotes the growth of beneficial microorganisms, (B) balances the gut microbiota. The produced SCFAs lower the pH of the intestinal lumen, (C) avoid pathogen colonization, and (D) increase the dissolution and absorption of Ca⁺² and Mg²⁺. (E) SCFAs provide an energy source for intestinal epithelial cells, (F) regulate fat metabolism, and (G) promote cytokine production. (H) Stimulates anti‐inflammatory cytokines (AIF‐CYTK's) production to maintain intestinal epithelial homeostasis, and (I) induces mucin production in enterocytes. FOS, fructooligosaccharides; GOS, galactooligosaccharides.