Current treatment for functional dyspepsia (FD) has limited and unsustainable efficacy. Probiotics have the sustainable potential to alleviate FD. This randomized controlled clinical trial (Chinese Clinical Trial Registry, ChiCTR2000041430) assigned 200 FD patients to receive placebo, positive-drug (rabeprazole), or Bifidobacterium animalis subsp. lactis BL-99 (BL-99; low, high doses) for 8-week. The primary outcome was the clinical response rate (CRR) of FD score after 8-week treatment. The secondary outcomes were CRR of FD score at other periods, and PDS, EPS, serum indicators, fecal microbiota and metabolites. The CRR in FD score for the BL-99_high group [45 (90.0%)] was significantly higher than that for placebo [29 (58.0%), p = 0.001], BL-99_low [37 (74.0%), p = 0.044] and positive_control [35 (70.0%), p = 0.017] groups after 8-week treatment. This effect was sustained until 2-week after treatment but disappeared 8-week after treatment. Further metagenomic and metabolomics revealed that BL-99 promoted the accumulation of SCFA-producing microbiota and the increase of SCFA levels in stool and serum, which may account for the increase of serum gastrin level. This study supports the potential use of BL-99 for the treatment of FD.

Combining probiotics and prebiotics in synbiotics may present a synergistic approach to improve type 2 diabetes mellitus (T2DM); however, further evidence is required to establish the comparative efficacy of synbiotics versus probiotics. This study aimed to evaluate the effects of Bifidobacterium animalis subsp. lactis MN-Gup (MN-Gup) and a synbiotic mixture of MN-Gup and galactooligosaccharide (MN-Gup-GOS) on glycemic control in T2DM patients and explore possible mechanisms. This randomized, double-blind, placebo-controlled clinical trial assigned 120 T2DM patients, to receive MN-Gup, MN-Gup-GOS, or placebo intervention for 12 weeks. The primary outcome was fasting blood glucose (FBG), with secondary outcomes including hemoglobin A1C (HbA1C), insulin, homeostatic model assessment of insulin resistance (HOMA-IR), inflammatory indicators, oxidative stress indicators, gastrointestinal hormones, gut microbiota, and bile acids (BAs). The median age of the 120 participants was 59 years (interquartile range: 55-62 years), with 40 being men. Compared to baseline, all three groups exhibited significant reductions in FBG. Additionally, the MN-Gup-GOS group demonstrated significant decreases in HbA1c, serum insulin, and HOMA-IR after intervention, whereas no such reductions were observed in the placebo and MN-Gup groups. Regarding the between-group comparisons, the MN-Gup-GOS intervention showed a significantly greater reduction in FBG compared to the placebo (least squares mean difference [95 % CI], -0.69 [-1.29, -0.10] mmol/L, P = 0.022) and MN-Gup (-0.59 [-1.17, -0.01], P = 0.047) group, but not for other indicators of glucose metabolism. Additionally, MN-Gup and MN-Gup-GOS intervention, especially the latter, significantly modified inflammation, oxidative stress, gut microbiota, serum BAs, and GLP-1 levels. Correlation analysis showed significant associations between changes in certain gut microbiota (Bifidobacterium) and BAs (deoxycholic acid and lithocholic acid) with glycemic indicators. The auxiliary effect of synbiotics MN-Gup-GOS on reducing FBG levels surpassed that of MN-Gup probiotics alone in T2DM patients, potentially attributed to the enhanced modulation of gut microbiota, BAs, and GLP-1 secretion. This study was registered on the website of www.chictr.org.cn, number ChiCTR2100052187.

Probiotics are live microorganisms with immunomodulatory effects in a strain-specific and dose-dependent manner. Bifidobacterium animalis subsp. lactis IU100 is a new probiotic strain isolated from healthy adults. This study aimed to evaluate the effects of IU100 on cyclophosphamide (CTX)-induced immunosuppression in mice. The results showed that IU100 significantly ameliorated CTX-induced decreases in body weight and immune organ indices. The promoted delayed-type hypersensitivity, serum hemolysins and immunoglobulin (IgA, IgG and IgM) levels after IU100 treatment indicated its enhancing role in cellular and humoral immunity. In addition, oral administration of IU100 increased serum cytokine (IL-1β, IL-2, IL-4, IL-6, IFN-γ, TNF-α) levels dose-dependently, which are associated with CTX-induced shifts in the Th1/Th2 balance. The probiotic IU100 also modulated the composition of gut microbiota by reducing the Firmicutes/Bacteroidetes ratio; increasing beneficial Muribaculaceae and the Lachnospiraceae NK4A136 group; and inhibiting harmful Clostridium sensu stricto 1, Faecalibaculum and Staphylococcus at the genus level. The above genera were found to be correlated with serum cytokines and antibody levels. These findings suggest that IU100 effectively enhances the immune function of immunosuppressed mice, induced by CTX, by regulating gut microbiota.

Background: Globally, master’s and doctoral students, especially pregraduate students, are under great pressure. Probiotics are emerging as a promising intervention to improve mental health via gut-brain axis.Objective: The aim of this study was to explore the impact of Lacticaseibacillus paracasei K56 supplementation on perceived stress among pregraduate students.Methods: We conducted a double-blind, randomized, placebo-controlled trial in 120 healthy master’s and doctoral students who faced graduation. Participants were randomly assigned to either probiotics (containing Lacticaseibacillus paracasei K56 6 × 10¹⁰ CFU / d) or placebo group for 2 weeks intervention. The main outcome was perceived stress assessed using Cohen’s Perceived Stress Scale-10 (PSS-10). The secondary outcomes were stress, depression, and anxiety assessed by Depression, Anxiety and Stress Scales (DASS), gastrointestinal symptoms, and sleep evaluated by corresponding scales. These outcomes were assessed at baseline, 1, and 2 weeks. Pre- and post-treatment serum biomarkers, gut microbiota composition and metabolites were also detected.Results: There was no difference in changes of PSS-10 scores from baseline to 2 weeks between the K56 groups and the placebo [mean (standard error): −1.68 (0.48) vs. -0.39 (0.46), p = 0.055]. Furthermore, the K56 group exhibited superior reductions in both stress [−2.15 (0.38) vs. -0.96 (0.49), p = 0.035] and anxiety symptoms [−1.54 (0.32) vs. 0.53 (0.43), p = 0.003] via DASS compared with the placebo group. Additionally, those receiving K56 also experienced improved sleep quality (p = 0.010) and elevated levels of serotonin (5-HT) (p = 0.038) compare to placebo group. Moreover, taking probiotics K56 could modulate the pressure-induced changes in gut microbiota composition, particularly by increasing the beneficial bacteria (Lacticaseibacillus and Lacticaseibacillus paracasei), while suppressing suspected pathogenic bacteria (Shieglla and Escherichia_coli). Metabolomic analysis revealed an increased in metabolites, especially butyric acid in the K56 group (p = 0.035). Notably, there was a significant negative correlation between relative abundance of lactobacillus and stress-related symptoms, whereas butyric acid showed a significant positive correlation with lactobacillus abundance level.Conclusion: This study suggested the potential benefits of K56 supplementation in alleviating stress and significant effect in reducing anxiety and insomnia among master’s and doctoral students, which may be attributed to K56-induced changes in microbial composition and butanoate metabolism.Clinical trial registration: Chictr.org.cn, identifier ChiCTR2300078447.

Probiotics have garnered increasing attention as a potential therapeutic approach for type 2 diabetes mellitus (T2DM). Previous studies have confirmed that Bifidobacterium animalis subsp. lactis MN-Gup (MN-Gup) could stimulate the secretion of glucagon-like peptide-1 (GLP-1) in NCI-H716 cells, but whether MN-Gup has a hypoglycemic effect on T2DM in vivo remains unclear. In this study, a T2DM mouse model was constructed, with a high-fat diet and streptozotocin in mice, to investigate the effect of MN-Gup on diabetes. Then, different doses of MN-Gup (2 × 10⁹ CFU/kg, 1 × 10¹⁰ CFU/kg) were gavaged for 6 weeks to investigate the effect of MN-Gup on glucose metabolism and its potential mechanisms. The results showed that a high-dose of MN-Gup significantly reduced the fasting blood glucose (FBG) levels and homeostasis model assessment-insulin resistance (HOMA-IR) of T2DM mice compared to the other groups. In addition, there were significant increases in the short-chain fatty acids (SCFAs), especially acetate, and GLP-1 levels in the MN-Gup group. MN-Gup increased the relative abundance of Bifidobacterium and decreased the number of Escherichia-Shigella and Staphylococcus. Moreover, the correlation analysis revealed that Bifidobacterium demonstrated a significant positive correlation with GLP-1 and a negative correlation with the incremental AUC. In summary, this study demonstrates that Bifidobacterium animalis subsp. lactis MN-Gup has significant hypoglycemic effects in T2DM mice and can modulate the gut microbiota, promoting the secretion of SCFAs and GLP-1.

The liver plays a crucial role in maintaining systemic iron homeostasis by secreting hepcidin, which is essential for coordinating iron levels in the body. Imbalances in iron homeostasis are associated with various clinical disorders related to iron deficiency or iron overload. Despite the clinical significance, the mechanisms underlying how hepatocytes sense extracellular iron levels to regulate hepcidin synthesis and iron storage are not fully understood. In this study, we identified Foxo1, a well-known regulator of macronutrient metabolism, which translocates to the nucleus of hepatocytes in response to high-iron feeding, holo-transferrin, and bone morphogenetic protein 6 (BMP6) treatment. Furthermore, Foxo1 plays a crucial role in mediating hepcidin induction in response to both iron and BMP signals by directly interacting with evolutionally conserved Foxo binding sites within the hepcidin promoter region. These binding sites were found to colocalize with Smad-binding sites. To investigate the physiological relevance of Foxo1 in iron metabolism, we generated mice with hepatocyte-specific deletion of Foxo1. These mice exhibited reduced hepatic hepcidin expression and serum hepcidin levels, accompanied by elevated serum iron and liver nonheme iron concentrations. Moreover, high-iron diet further exacerbated these abnormalities in iron metabolism in mice lacking hepatic Foxo1. Conversely, hepatocyte-specific Foxo1 overexpression increased hepatic hepcidin expression and serum hepcidin levels, thereby ameliorating iron overload in a murine model of hereditary hemochromatosis (Hfe−/− mice). In summary, our study identifies Foxo1 as a critical regulator of hepcidin and systemic iron homeostasis. Targeting Foxo1 may offer therapeutic opportunities for managing conditions associated with aberrant iron metabolism.