Improving Growth Dynamics of Faecalibacterium prausnitzii by Exposure to Prebiotics
An in vitro laboratory study examined how seven prebiotics — fructooligosaccharides (FOS), inulin, pectin, resistant starch, arabinoxylan, golden kiwi fiber, and riboflavin (vitamin B2), affect the growth, bile tolerance, and immune-related activity of Faecalibacterium prausnitzii, a key butyrate-producing gut bacterium. Researchers measured bacterial doubling time, growth under bile salt stress (0–0.5%), and changes in immune signaling by exposing THP-1 human monocytic cells to bacterial culture supernatants and assessing tumor necrosis factor alpha (TNF-α) expression.
All prebiotics significantly reduced doubling time, meaning they accelerated bacterial growth. Inulin, pectin, resistant starch, and riboflavin showed clear dose-dependent effects (p < 0.0001 in multiple comparisons). Under bile stress, doubling time increased from ~2 hours to >6 hours at 0.5% bile in control media, confirming strong growth inhibition. FOS and arabinoxylan partially protected against bile at lower concentrations (0.1–0.25%), while pectin, riboflavin, and resistant starch showed threshold-type protection. Golden kiwi fiber provided more limited resilience.
Supernatants from prebiotic-conditioned cultures significantly altered TNF-α expression (p = 0.043), with pectin producing the strongest immune response. Effects on other cytokines, including IL-10 and IL-6, were variable and not statistically significant. This suggests that prebiotic structure shapes the metabolites produced by F. prausnitzii, which in turn influence immune signaling.
These findings indicate that specific prebiotics can enhance growth and stress resilience of F. prausnitzii and modify its immune-related activity in a substrate-dependent manner. However, the work was conducted in vitro using a single bacterial strain and one immune cell model, limiting clinical translation.
Future studies should validate these effects in vivo, test multiple strains, and identify the metabolites responsible for immune modulation. Overall, the study reinforces that prebiotic structure determines microbial function and downstream immune effects, an important consideration in synbiotic design.
