Optimizing Akkermansia muciniphila Isolation and Cultivation: Insights into Gut Microbiota Composition and Potential Growth Promoters in a Chinese Cohort

Abstract

The study aims to analyze the composition of the gut microbiota in Chinese individuals using metagenomic sequencing technology, with a particular focus on the abundance of Akkermansia muciniphila (Akk). To improve the efficiency of Akk isolation and identification accuracy, modifications were made to the enrichment culture medium and 16S rRNA universal primers. Additionally, potential growth-promoting factors that stimulate Akk growth were explored through in vitro screening. The research results revealed that the abundance of Akk in Chinese fecal samples ranged from 0.004% to 0.4%. During optimization, a type of animal protein peptide significantly enhanced the enrichment efficiency of Akk, resulting in the isolation of three Akk strains from 14 fecal samples. Furthermore, 17 different growth-promoting factors were compared, and four factors, including galactose, sialic acid, lactose, and chitosan, were identified as significantly promoting Akk growth. Through orthogonal experiments, the optimal ratio of these four growth-promoting factors was determined to be 1:1:2:1. After adding 1.25% of this growth-promoting factor combination to the standard culture medium, Akk was cultivated at 37° for 36 h, achieving an OD600nm value of 1.169, thus realizing efficient proliferation and optimized cultivation of Akk. This study provides important clues for a deeper understanding of the gut microbiota composition in Chinese individuals, while also offering effective methods for the isolation and cultivation of Akk, laying the groundwork for its functional and application research in the human body.