Biodiversity and Physiological Characteristics of Novel Faecalibacterium prausnitzii Strains Isolated from Human Feces

Abstract

<i>Faecalibacterium prausnitzii</i> is prevalent in the human gut and is a potential candidate for next-generation probiotics (NGPs) or biotherapeutics. However, the biodiversity and physiological characteristics of <i>Faecalibacterium prausnitzii</i> remain unclear. This study isolated 26 novel <i>F. prausnitzii</i> strains from human feces using a combination of negative screening and prime-specific PCR amplification (NSPA). Based on a 16S rRNA gene analysis, <i>F. prausnitzii</i> strains can be classified into two main phylogroups (phylogroups I and II), which were further clustered into five subgroups (I-A, II-B, II-C, II-D, and II-E). The ultrastructure, colony morphology, growth performance, and short-chain fatty acids (SCFAs)-producing ability were found to be variable among these <i>F. prausnitzii</i> isolates. The optimal pH for the isolates growth ranged between 6.0 and 7.0, while most isolates were inhibited by 0.1% of bile salts. Antimicrobial resistance profiles showed that all <i>F. prausnitzii</i> isolates were susceptible to vancomycin, whereas >80% were kanamycin and gentamicin resistant. Additionally, all strains can utilize maltose, cellulose, and fructose but not xylose, sorbose, and 2'-FL. Overall, our work provides new insights into the biodiversity and physiological characteristics of <i>F. prausnitzii</i>, as well as the choices of strains suitable for NGPs.