Protective effects of a new generation of probiotic Bacteroides fragilis against colitis in vivo and in vitro

Abstract

Bacteroides fragilis, one of the potential next-generation probiotics, but its protective mechanism is not yet known. We aimed to characterize the anti-inflammatory effect of B. fragilisATCC25285 and to elucidate its mechanism through in vivo and in vitro experiments. An in vitro model of inflammation by induction of colonic cells with TNF-a, and co-cultured with B. fragilis to detect cell viability, apoptosis and invasive capacity. Furthermore, critical proteins of the TLR/NF-κB pathway and the inflammatory cytokines were measured. For animal trials, C57BL/6 J male mice were orally administered B. fragilis or PBS once daily for 21 days. Colitis was induced by drinking 2.5% DSS from days 0 to 7. The mice were weighed daily and rectal bleeding, stool condition and blood in the stool were recorded. We found that B. fragilis treatment alone was harmless and had no effect on cell viability or apoptosis. While predictably TNF-α decreased cell viability and increased apoptosis, B. fragilis attenuated this deterioration. The NF-κB pathway and inflammatory cytokines IL-6 and IL-1β activated by TNF-α were also blocked by B. fragilis. Notably, the metabolic supernatant of B. fragilis also has an anti-inflammatory effect. Animal studies showed that live B. fragilis rather than dead strain ameliorated DSS-induced colitis, as evidenced by weight loss, shortened colon length and enhanced barrier function. The colonic tissue levels of inflammatory cytokines (TNF-α, IL-1β, IL-6) were decreased and IL-10 was increased as a result of B. fragilis administration. In conclusion, B. fragilis ATCC25285 exhibited anti-inflammatory effects whether in vivo or in vitro, and it may be a potential probiotic agent for improving colitis.

Therapeutic Potential of Bacteroides fragilis SNBF-1 as a Next-Generation Probiotic: In Vitro Efficacy in Lipid and Carbohydrate Metabolism and Antioxidant Activity

“…B. fragilis administration in animal models leads to the binding of PSA with B cells, crucial for inducing regulatory CD4+ and CD8+ T cells that secrete IL-10, thereby controlling innate inflammatory responses. This process results in decreased colonic levels of inflammatory cytokines (TNF-α, IL-1β, IL-6) and an increase in IL-10 [ 32 ], highlighting the anti-inflammatory effects of B. fragilis .…”

Correlations between Gut Microbiota and Hematological, Inflammatory, Biochemical and Oxidative Stress Parameters in Treatment-Naïve Psoriasis Patients

“…In a study conducted by Zang et al, the authors evaluated how the intestinal microbiota influences the development of psoriasis and/or psoriatic arthritis, with the Bacteroidetes phylum and the Prevotella genus being associated with a protective mechanism ( p = 0.033 and p = 0.045, respectively) [ 38 ]. Furthermore, He et al emphasized the protective role of Bacteroides in TNF-alpha-induced inflammation, the latter being a key cytokine involved in the pathophysiology of psoriasis [ 39 ].…”

Between Dysbiosis, Maternal Immune Activation and Autism: Is There a Common Pathway?

“…Recent studies also point to the anti-inflammatory effects of B. fragilis in the gut. Due to B. fragilis administration, levels of colonic pro-inflammatory cytokines such as TNF-α, IL-1β, and IL-6 were reduced and IL-10 increased [ 259 ].…”

“…producing SCFAs [92][93][94] GABA releasing [129] preventing MIA-Induced ASD-relevant deficits in adult offspring [304] preventing parvalbumin-positive neuron loss, increased proinflammatory cytokines levels in maternal serum and fetal brain, and decreased GABA levels [304] intestinal refilling of tryptophan (Bifidobacterium infantis) [120] inducing changes in γ-aminobutyric acid (L. rhamnosus) [107] taking part in maintaining tight junctions between cells [55] preventing the overgrowth of Candida [56] promoting oxytocin levels (L. reuteri) [277] B. fragilis: regulating intestinal barrier integrity [110] lowering Il-6 in colon [110,259] reducing gut permeability [53] promoting stem cell regeneration and increase mucus secretion in intestines [254] promoting the development of regulatory T cells and IL-22 secretion [255] Nutrients…”