Evaluation of Four Multispecies Probiotic Cocktails in a Human Colonic Fermentation Model

Bacteriotherapy represents an attractive approach for both prophylaxis and treatment of human diseases. However, combining probiotic bacteria in "cocktails" is underexplored, despite its potential as an alternative multi-target therapy. Herein, three-strain probiotic mixtures containing different combinations of Bacillus (Bc.) coagulans [ATB-BCS-042], Levilactobacillus (Lv.) brevis [THT 0303101], Lacticaseibacillus (Lc.) paracasei [THT 031901], Bacillus subtilis subsp. natto [ATB-BSN-049], Enterococcus faecium [ATB-EFM-030], and Bifidobacterium (Bf.) animalis subsp. lactis [THT 010802] were prepared. Four cocktails (PA: Bc. coagulans + Lv. brevis + Lc. paracasei, PB: Bc. subtilis subsp. natto + Lv. brevis + Lc. paracasei, PC: E. faecium + Lv. brevis + Lc. paracasei, PD: Bc. coagulans + Lv. brevis + Bf. animalis subsp. lactis) were tested using a short-term (72 h) simulation of the human colonic microbiota in a final dose of 6 × 109 CFU. All these probiotic mixtures significantly increased butyrate production compared to the parallel control experiment. PA and PB promoted a bifidogenic effect and facilitated lactobacilli colonization. Furthermore, reporter gene assays using the AhR_HT29-Lucia cell line revealed that fermentation supernatants from PA and PB notably induced AhR transactivity. Subsequent examination of the metabolic outputs of PA and PB in intestinal epithelial models using cell culture inserts suggested no significant impact on the transepithelial electrical resistance (TEER). Assessment of the expression of proinflammatory and anti-inflammatory cytokines, as well as AhR-related target genes in the Caco-2 cell monolayers indicated that PB's metabolic output upregulated most of the measured endpoints. This in vitro investigation evaluated the potential impact of four multispecies probiotic mixtures in the human colonic microbiota and identified a promising formulation comprising a combination of Bc. subtilis subsp. natto, Lv. brevis, and Lc. paracasei as a promising formulation for further study.

Isolation and In Vitro Culture of Human Gut Progenitor Cells

The gastrointestinal epithelium is a highly regenerative organ, where each cell is replaced in a cycle of 4-6 days, depending on the mammalian species. This highly proliferative state is driven by gastrointestinal stem and progenitor cells, located at the base of crypts. These cells give rise to at least six types of differentiated epithelial cells, each with a distinct function in maintaining homeostasis between the intestinal interface and the luminal environment. The isolation and culture of these cells from mammalian gastrointestinal tissue is a novel technique, which allows for the generation and maintenance of an in vitro culture system for adult epithelial cells. There are two predominant methods for isolation and propagation of gastrointestinal epithelial cells, the first is the organoid system developed in 2009, and the second is a later version known as the L-WRN spheroid system. In this chapter, we describe the method to isolate and culture human gastrointestinal stem and progenitor cells and culture them as three-dimensional spheroids using L-WRN cell conditioned media.