S. boulardii Fails to Hold Its Cell Wall Integrity against Nonpathogenic E. coli: Are Probiotic Yeasts Losing the Battle?

Pre-Administration of Saccharomyces boulardii-Derived Postbiotics Effectively Prevents Dextran Sulfate Sodium-Induced Colitis in Mice

Ulcerative colitis (UC) is effectively alleviated by Saccharomyces boulardii (S. boulardii), an important probiotic. Postbiotics, defined as beneficial non-viable microorganisms and/or their components, can potentially improve gut health. In this study, we utilized S. boulardii to prepare postbiotics via freeze-drying and spray-drying methods, characterized the resulting postbiotics, and investigated their efficacy and underlying mechanisms in preventing UC. In a mouse model of UC induced by dextran sulfate sodium (DSS), we found that prevention with two forms of S. boulardii postbiotics alleviated colitis symptoms triggered by DSS, mitigated colon tissue damage, maintained the distribution of intestinal occludin and ZO-1 proteins, and suppressed the secretion and expression of TNF-α, IL-1β, and IL-6 in serum and colon tissues. Additionally, S. boulardii postbiotics mitigated dysbiosis by modulating gut microbiota composition, including the balance between Bacteroidota and Firmicutes (F/B), as well as the levels of Akkermansia, Muribaculaceae, Dubosiella, and Turicibacter. In conclusion, as a novel biotherapeutic agent, S. boulardii postbiotics effectively prevent DSS-induced UC in mice. Compared to live S. boulardii, postbiotics may hold greater potential for UC prevention.

Postbiotics from Saccharomyces cerevisiae RC016 Cell Wall (Formerly Classified as a Prebiotic): Exploring In Vitro and In Vivo Benefits

The objective of this work was to obtain postbiotics derived from the cell wall of Saccharomyces cerevisiae RC016 by applying different strategies and to characterize them in terms of their antitoxin capacity in vitro and their in vivo impact on intestinal integrity, evaluating the modulation of the microbiota and the histomorphometry of the intestine. Moreover, the impact of dried strategies on chemical groups related to food toxin adsorption was analyzed. Nine mechanical and enzymatic cell disruption treatments were assayed using S. cerevisiae RC016 biomass to obtain the postbiotic under study. Then, postbiotics were characterized using high-resolution optical microscopy and assayed for in vitro studies related to their antitoxin activity (adsorption and degradation of aflatoxin B1). Postbiotics were dried using freeze-dried and spray-dried methods and subjected to FT-IR spectroscopy. Finally, the postbiotic efficacy was determined on an in vivo study conducted on 16 male and female BALB/c mice, divided into two experimental groups, each experimental group (n = 8) separated by sex in different cages (four females and four males): untreated (control) and yeast wall treated (YW); (a) female control; (b) male control; (c) female control + YW; (d) male control + YW. The intestinal microbiota showed significant differences in the counts of LAB and enterobacteria between male and female animals. The histomorphometric analysis showed a significant increase in villi height and width, as well as crypt depth, compared to the control group in male mice with the addition of the postbiotic solution of S. cerevisiae. These findings open new avenues for further optimizing postbiotics' production processes and evaluating their efficacy across diverse conditions and populations.

Both Saccharomyces boulardii and Its Postbiotics Alleviate Dextran Sulfate Sodium-Induced Colitis in Mice, Association with Modulating Inflammation and Intestinal Microbiota

OBJECTIVE

To investigate the effect of Saccharomyces boulardii and its freeze-dried and spray-dried postbiotics on the intervention and potential mechanism of dextran sulfate sodium (DSS)-induced ulcerative colitis in mice. [Methods] After the acclimation period of C67BL/6J mice, a colitis model was constructed by applying 2% DSS for 7 d, followed by 7 d of intervention. Subsequently, the disease activity index (DAI), organ index, colon length, colon HE staining of pathological sections, ELISA for blood inflammatory factors (Interleukin (IL)-1β, IL-6, IL-10, Tumor necrosis factor (TNF)-α), Real time quantitative polymerase chain reaction (RT-qPCR) to determine the levels of colonic inflammatory factors (IL-1β, IL-6, IL-10, TNF-α), Occludin gene expression, and intestinal flora were assessed to evaluate the protective effects of S. boulardii and its postbiotics on colitis in mice.

RESULTS

Compared with the DSS group, S. boulardii and the postbiotics interventions effectively improved colonic shortening and tissue damage, increased the expression of intestinal tight junction protein, reduced the secretion of pro-inflammatory factors, increased the secretion of anti-inflammatory factors, and maintained the homeostasis of intestinal microorganisms. Postbiotics intervention is better than probiotics.

CONCLUSIONS

S. boulardii and its postbiotics can effectively alleviate DSS-induced colitis in mice through modulating host immunity and maintaining intestinal homeostasis. Postbiotics are promising next-generation biotherapeutics for ulcerative colitis treatment.

Beneficial insights into postbiotics against colorectal cancer

Colorectal cancer (CRC) is one of the most prevalent and life-threatening cancer types with limited therapeutic options worldwide. Gut microbiota has been recognized as the pivotal determinant in maintaining gastrointestinal (GI) tract homeostasis, while dysbiosis of gut microbiota contributes to CRC development. Recently, the beneficial role of postbiotics, a new concept in describing microorganism derived substances, in CRC has been uncovered by various studies. However, a comprehensive characterization of the molecular identity, mechanism of action, or routes of administration of postbiotics, particularly their role in CRC, is still lacking. In this review, we outline the current state of research toward the beneficial effects of gut microbiota derived postbiotics against CRC, which will represent the key elements of future precision-medicine approaches in the development of novel therapeutic strategies targeting gut microbiota to improve treatment outcomes in CRC.

A bioinspired Janus polyurethane membrane for potential periodontal tissue regeneration

Guided tissue regeneration (GTR) is the main therapeutic method for periodontal tissue regeneration. The key to the GTR strategy is the membrane which can assist the reconstruction of bone tissue in the periodontal defect and prevent the migration of epithelium and fibroblasts to the defect. However, the existing periodontal membrane cannot effectively promote periodontal tissue regeneration due to the limited bioactivity and physicochemical function. Here, we developed a bioinspired degradable polyurethane membrane with Janus surface morphology by integrating bioactive dopamine (DA) and an antibacterial Gemini quaternary ammonium salt (QAS). The Janus surface of the membrane is fabricated through spontaneous microphase separation, resulting from the different migration of functional segments between the air-contact upper surface with enriched antibacterial QAS and the substrate-contact bottom with enriched bioactive DA. The smooth surface of the upper membrane used to face the soft tissues can reduce cell adhesion to suppress the migration of fibroblasts, while the rough surface with a topological micro-pit structure of the bottom side facing the bone has excellent function of autonomic mineralization and cell adhesion to promote bone tissue reconstruction. In addition, the membrane containing the antibacterial QAS shows excellent antibacterial effect on common oral pathogens, such as S. aureus and S. mutans. Moreover, the specific dopamine group also endows the membrane with excellent antioxidant efficiency. In vivo research shows that this Janus polyurethane membrane can effectively promote periodontal tissue regeneration in a rat periodontal defect model. Combined with its excellent mechanical properties and biocompatibility, the polyurethane membrane is a promising material for potential periodontal tissue regeneration.