Characterization of Short Chain Fatty Acids Produced by Selected Potential Probiotic Lactobacillus Strains

Abstract

Short-chain fatty acids (SCFAs), particularly butyrate, have received considerable attention with regard to their anti-cancer efficacy in delaying or preventing colorectal cancer. Several studies have reported that certain probiotic strains could produce SCFAs; however, different strains yielded different amounts of SCFAs. This study explored the ability to produce SCFAs of the following probiotic strains: <i>Lacticaseibacillus paracasei</i> SD1, <i>Lacticaseibacillus rhamnosus</i> SD4, <i>Lacticaseibacillus rhamnosus</i> SD11, and <i>Lacticaseibacillus rhamnosus</i> GG. <i>L. paracasei</i> SD1 and <i>L. rhamnosus</i> SD11 exhibited high butyrate production, particularly when the strains were combined. The functions of the SCFAs were further characterized; the SCFAs exerted a positive anti-cancer effect in the colon via various actions, including inhibiting the growth of the pathogens related to colon cancer, such as <i>Fusobacterium nucleatum</i> and <i>Porphyromonas gingivalis</i>; suppressing the growth of cancer cells; and stimulating the production of the anti-inflammatory cytokine IL-10 and antimicrobial peptides, especially human β-defensin-2. In addition, the SCFAs suppressed pathogen-stimulated pro-inflammatory cytokines, especially IL-8. The results of this study indicated that selected probiotic strains, particularly <i>L. paracasei</i> SD1 in combination with <i>L. rhamnosus</i> SD11, may serve as good natural sources of bio-butyrate, which may be used as biotherapy for preventing or delaying the progression of colon cancer.