In Vitro Simulation of Human Colonic Fermentation: A Practical Approach towards Models’ Design and Analytical Tools

Abstract

The human colonic microbiota plays an important role in the food digestion process and has a key role in maintaining health status. This community of microbes is inter-individually different due to several factors that modulate its composition. Among them, diet is one of the most relevant, which, in turn, is affected by environmental, economic, and cultural considerations. These pieces of evidence have promoted the study of the influence of diet on gut microbiota and the development of in vitro models that simulate the colonic digestion of foods. This narrative review aims to present a technical approach of the in vitro gut models available to evaluate the impact of diet on human colonic microbiota. A description and comments on the main characteristics, parameters, applicability, faecal inoculum preparation, and analytical tools are made. Despite the progress of in vitro colonic digestion models and metaomic applicability in this research field, there are still some challenges to face due to the lack of a consensus on the methodologies to conduct in vitro colonic digestions and the need to integrate the metaomic data to fully understand the influence of food in human colonic microbiota.

In vitro human gut microbiota fermentation models: opportunities, challenges, and pitfalls

“…A mechanistic understanding of how the microbiota can lead to disease and how its function can be modulated requires these complex interactions to be disentangled. A holistic approach combining in vitro and animal models with human studies in multiscale strategies has been promoted to decipher the role of the gut microbiota in humans and elucidate hypothesis-based mechanisms [10][11][12] . In vitro HGM models involving complex communities are increasingly being used in medical and nutritional research.…”

Modulation of the gut microbiota and short-chain fatty acid production by gac fruit juice and its fermentation in in vitro colonic fermentation

“…To better understand changes induced by FGJ, considering additional microbe-related metabolites like polyphenolic breakdown products, volatile compounds, lipopolysaccharides (LPSs), β-carotene concentration, and antioxidant capacity would be valuable for further study. 33…”

“…To better understand changes induced by FGJ, considering additional microberelated metabolites like polyphenolic breakdown products, volatile compounds, lipopolysaccharides (LPSs), β-carotene concentration, and antioxidant capacity would be valuable for further study. 33 Changes in SCFA production have been linked to shifts in gut microbiota distribution. Notably, there are positive correlations between Lactobacillus spp.…”

The fate of mamaku gum in the gut: effect on in vitro gastrointestinal function and colon fermentation by human faecal microbiota

“…This leads to a change in the environmental conditions (i.e., oxidation-reduction potential and pH) and eventually, the interruption of bacterial growth and activity. 55 For this reason, the simulation length is usually short (mainly 24 h) and the pH during in vitro fermentation studies is monitored (along with SCFAs quantification) as any drastic change in pH could limit the growth of bacteria.…”