The emerging role of the small intestinal microbiota in human health and disease

ABSTRACT

The human gut microbiota continues to demonstrate its importance in human health and disease, largely owing to the countless number of studies investigating the fecal microbiota. Underrepresented in these studies, however, is the role played by microbial communities found in the small intestine, which, given the essential function of the small intestine in nutrient absorption, host metabolism, and immunity, is likely highly relevant. This review provides an overview of the methods used to study the microbiota composition and dynamics along different sections of the small intestine. Furthermore, it explores the role of the microbiota in facilitating the small intestine in its physiological functions and discusses how disruption of the microbial equilibrium can influence disease development. The evidence suggests that the small intestinal microbiota is an important regulator of human health and its characterization has the potential to greatly advance gut microbiome research and the development of novel disease diagnostics and therapeutics.

KEYWORDS:

• small Intestine
• microbiota
• microbiome
• metabolism
• immunity
• human health

Acknowledgements

We would like to acknowlegde A. Petrenko's involvement in the creative design of Figure 1.

Disclosure statement

RKW acted as a consultant for Takeda and received unrestricted research grants from Takeda and Johnson and Johnson pharmaceuticals and speaker fees from AbbVie, MSD, Olympus and AstraZeneca. No potential conflict of interest were reported by other authors.

Data availability statement

Data sharing is not applicable to this article as no new data were created or analyzed in this review.

Additional information

Funding

AVV and RKW are supported by Health~Holland grant LWV21.165/LSHM21077. RKW is supported by HORIZON-HLTH-2022-STAYHLTH-02-0 and the Seerave Foundation.