Inflammatory bowel disease (IBD) is a chronic inflammatory disease associated with gut dysbiosis. This study aimed to investigate the effects of heat-killed Bifidobacterium bifidum B1628 (HB1628) in dextran sulfate sodium (DSS)-induced colitis in mice. The following three mouse groups were included (n = eight per group): NC (normal control), DSS (colitis), and HB1628 (colitis and postbiotic). The mice in the DSS group showed significant weight loss and histological damage, developed bloody diarrhea, scored high in the disease activity index (DAI), and exhibited increases in pro-inflammatory cytokines (interleukin [IL]-1β, IL-6, and tumor necrosis factor [TNF]-α) and decreases in an anti-inflammatory cytokine (IL-13) in the serum. These changes were accompanied by gut microbiota modulation in colitis mice (decreases in Rikenellaceae and Eubacterium; increases in Peptostreptococcaceae, Bacteroides vulgatus, and Parasutterella excrementihominis). The HB1628 group had lower DAIs, histology scores, and serum levels of pro-inflammatory cytokines (IL-1β and TNF-α), but higher levels of an anti-inflammatory cytokine (IL-13), compared with the DSS group, suggesting a less severe inflammatory state after the HB1628 intervention. Additionally, HB1628 improved DSS-induced gut dysbiosis, which is evidenced by increases in intestinal beneficial bacteria, such as Lactobacillus, and decreases in known unfavorable taxa in IBD, e.g., Porphyromonadaceae, Subdoligranulum, Lachnospiraceae bacterium 3_1_46FAA, and Alistipes indistinctus. Functional metagenomics revealed three significantly enriched metabolic pathways in the HB1628 group (namely, the aerobic respiration I [cytochrome c] pathway and the superpathways of L-phenylalanine biosynthesis and L-tryptophan biosynthesis, respectively). In conclusion, our results showed that HB1628 effectively improved the inflammation state and tissue damage in DSS-induced colitis mice, and the symptom relief effect was accompanied by obvious gut microbiota remodulation.

Inflammatory bowel disease (IBD) is a recurring inflammatory disease of the gastrointestinal tract with unclear etiology, but it is thought to be related to factors like immune abnormalities and gut microbial dysbiosis. Probiotics can regulate host immunity and gut microbiota; thus, we investigated the alleviation effect and mechanism of the strain Lactobacillus gasseri G098 (G098) on dextran sodium sulfate (DSS)-induced colitis in mice. Three groups of mice (n = 8 per group) were included: normal control (NC), DSS-induced colitis mice (DSS), and colitis mice given strain (G098). Our results showed that administering G098 effectively reversed DSS-induced colitis-associated symptoms (mitigating weight loss, reducing disease activity index and pathology scores; p < 0.05 in all cases) and prevented DSS-induced mortality (62.5% in DSS group; 100% in G098 group). The mortality rate and symptom improvement by G098 administration was accompanied by a healthier serum cytokine balance (significant decreases in serum pro-inflammatory factors, interleukin (IL)-6 [p < 0.05], IL-1β [p < 0.01], and tumor necrosis factor (TNF)-α [p < 0.001], and significant increase in the serum anti-inflammatory factor IL-13 [p < 0.01], compared with DSS group) and gut microbiome modulation (characterized by a higher gut microbiota diversity [p < 0.05], significantly more Firmicutes and Lachnoclostridium [p < 0.05], significantly fewer Bacteroidetes [p < 0.05], and significant higher gene abundances of sugar degradation-related pathways [p < 0.05], compared with DSS-treated group). Taken altogether, our results suggested that G098 intake could mitigate DSS-induced colitis through modulating host immunity and gut microbiome, and strain treatment is a promising strategy for managing IBD.

Gut microbiome may influence tumor growth and cancer treatment efficacy, so it is a potential target for tumor prevention/treatment. This pilot study investigated the preventive and therapeutic effects of a probiotic strain, Lacticaseibacillus rhamnosus Probio-M9 (Probio-M9), against murine mammary cancer. Thirty-six female mice were randomly divided into three groups (n = 12 per group): control (without tumor transplantation), model (tumor transplantation; no probiotic administration), and probiotic (30-day oral gavage of probiotic, started seven days before tumor transplantation). Changes in tumor size were recorded, and blood, tumor tissue, and stool samples were collected at the end of the trial for analyses. Comparing with the model group, the probiotic group had a significantly smaller tumor volume (p < 0.05), a higher fecal microbiota Shannon diversity index, with significant modifications in the gut microbiota structure (p < 0.05), characterized by more Alistipes sp._2, Porphyromonadaceae bacterium_7, and Bacteroidales bacterium 55_9 (p < 0.05). Additionally, Probio-M9 administration elevated the serum IFN-γ, IL-9, IL-13, and IL-27 levels and several metabolites (e.g., pyridoxal, nicotinic acid, 3-hydroxybutyric acid, glutamine; p < 0.05), while reducing IL-5 (p < 0.05). These changes might be associated with the protective effect of Probio-M9 against mammary tumor growth. Thus, probiotic administration could harness host gut microbiome in anti-cancer responses.

Background/Objectives: Irritable bowel syndrome (IBS) is a highly prevalent functional gastrointestinal disorder. Emerging evidence implicates gut microbiota dysbiosis in IBS pathogenesis, and probiotic interventions targeting microbial modulation hold therapeutic promise. Methods: this study used fecal microbiota transplantation to establish a mouse model of IBS before evaluating the effects of the complex probiotic by using metagenomics and targeted metabolomics to explore the potential mechanism. Results: After 14 days, the probiotic relieved constipation, reduced inflammation and intestinal permeability, lowered 5-HT levels and increased serotonin transporter (SERT) expression in tissues. Metagenomic analysis showed a reduced inflammation-related species abundance. It also decreased fecal butyric acid, acetic acid and tryptophan levels in IBS mice. Conclusions: The probiotic complex effectively alleviated IBS symptoms in mice by modulating gut microbiota and fecal metabolites, providing insights for future IBS research and treatment.

Inflammatory bowel disease (IBD) is a chronic non-specific gut inflammatory disease. Conventional treatments are insufficient to support long-term disease remission, so there is an urgent need to search for new IBD treatment options. This study evaluated the alleviation effect of Lactobacillus (L.) helveticus H9 on dextran sodium sulfate (DSS)-induced colitis rats. We found that administering L. helveticus H9 significantly reduced DAI (disease activity index) scores (p ≤ 0.05), spleen weights (p ≤ 0.05), and colonic tissue damage in the colitis rats, while increasing the body weight gain rate. Compared with the DSS group, L. helveticus H9-receiving rats had less serum tumor necrosis factor-α (p ≤ 0.05) and interleukin-1β (p < 0.01), a higher gut microbiota diversity, and significantly more Alistipes senegalensis (p ≤ 0.05) and Parabacteroides distasonis (p < 0.01). On the metabolomics level, 65 significantly differential metabolites (VIP > 1, p < 0.05, fold change > 2 or <0.5) were identified between the probiotic and DSS groups. Some significantly enriched pathways were identified in the fecal metabolome of the probiotic group, including Sphingolipid metabolism, Linoleic acid metabolism, alpha-Linolenic acid metabolism, Arachidonic acid metabolism, Glycerophospholipid metabolism, Pyrimidine metabolism, Tryptophan metabolism, Fatty acid biosynthesis and Steroid hormone biosynthesis metabolic pathways, and lecithin is an important differential metabolite interconnecting several of the enriched pathways. In summary, administering L. helveticus H9 modulated the gut microbiota, metabolome, and host immune response, which could relate to symptom alleviation in the colitis rats. Our study provides interesting data regarding the use of probiotics in managing chronic colitis.