Here, we explored the correlation between gut microbiota and bone health and the effects of high-fructose corn syrup (HFCS) on both. Sixteen 3-week-old male C57BL/6J mice were randomly divided into two groups and given purified water (control group) or 30% HFCS in water (HFCS group) for 16 weeks. The effects of HFCS were assessed via enzyme-linked immunosorbent assays, histopathological assays of colon and bone, and 16S rDNA sequence analysis of gut microbiota. The serum of HFCS group mice had lower levels of bone alkaline phosphatase (BALP), bone Gla protein (BGP), insulin-like growth factor 1 (IGF-1), and testosterone, and higher levels of type I collagen carboxyl-terminal telopeptide (ICTP) and tartrate-resistant acid phosphatase (TRAP) than that of the control group. HFCS caused trabecular bone damage by decreasing trabecular number and thickness and increasing trabecular separation. The HFCS group colons were shorter than the control group colons. The HFCS-fed mice showed mild, localized shedding of epithelial cells in the mucosal layer, focal lymphocytic infiltration of the lamina propria, mild submucosal edema, and loosely arranged connective tissue. The HFCS group displayed lower abundance and altered composition of gut microbiota. The abundance of Defluviitaleaceae UCG-011, Erysipelatoclostridium, Ruminococcaceae UCG-009, Lactobacillus, Blautia, and Parasutterella increased, positively correlating with BALP, BGP, IGF-1, and testosterone levels, and negatively correlating with ICTP and TRAP levels. Our study revealed a potential diet-gut microbiota-bone health axis.

Introduction: Mineral deficiency is a major nutritional issue that threatens human health. Probiotics, owing to their ability to enhance intestinal absorption, are regarded as potential nutritional modulators. Methods: In this study, multiple strains of Lactobacillus and Bifidobacterium were systematically evaluated for their in vitro fermentation metabolism and mineral absorption-promoting properties to screen probiotic candidates possessing mineral uptake-enhancing potential. Eight strains selected via multi-parameter screening were further evaluated for their mineral absorption-promoting capacity using the Caco-2 cell model. Results: The results revealed significant strain-specific differences in acid production capacity, short-chain fatty acids (SCFAs) generation, and phytase activity. Strains L. paracasei PC-01, B. lactis Ca360, L. plantarum Fe-01, B. lactis MN16620, and L. brevis MN14440 exhibited pronounced acid-producing ability, indicated by markedly decreased fermentation broth pH values. L. reuteri MN11965, L. acidophilus MN06785, L. brevis MN06618, and L. rhamnosus MN08244 showed significantly higher L-lactic acid yields than the positive control. Acetate was the predominant metabolite, followed by propionic and butyric acids, with L. curvatus MN15933, B. lactis Ca360, and B. lactis MN16620 showing particularly strong butyrate production. Phytase activity assays revealed that both intracellular and extracellular enzyme activities of L. plantarum Fe-01 and B. lactis Ca360 were significantly higher than those of L. plantarum 299v. In the Caco-2 cell model, all tested strains significantly increased calcium uptake, with L. plantarum Fe-01 and B. lactis Ca360 showing the highest transmembrane calcium transport efficiency. These two strains also markedly enhanced iron absorption, while B. lactis Ca360 exhibited zinc uptake and transport levels comparable to the positive control. Discussion: Comprehensive analysis indicated that strain B. lactis Ca360 demonstrated the most prominent effect in promoting calcium, iron, and zinc absorption, likely through mechanisms involving acid production-induced pH reduction and phytate hydrolysis facilitation. This study provides systematic verification of the integrated mechanisms by which probiotics promote mineral absorption and offers both theoretical support and strain resources for the development of targeted probiotics aimed at improving mineral bioavailability.

Zinc deficiency is closely associated with oxidative stress, inflammation, and intestinal dysfunction. In this study, a zinc-deficient mouse model was used to evaluate the effects of Bifidobacterium animalis subsp. lactis Ca360 ( B. lactis 360) combined with ZnSO4 on zinc metabolism, antioxidant capacity, intestinal integrity, and gut microbiota composition. Zinc deficiency significantly reduced organ indices and zinc levels, impaired antioxidant enzyme activities, and induced oxidative stress and inflammation. Combined supplementation with B. lactis Ca360 and ZnSO4 markedly restored zinc status, enhanced superoxide dismutase and glutathione peroxidase activities, reduced nitric oxide levels, and alleviated colonic mucosal damage, with superior effects in several parameters compared with Lactiplantibacillus plantarum 299v ( L. plantarum 299v). At the molecular level, B. lactis Ca360 upregulated duodenal zinc uptake and storage–related genes while suppressing pro-inflammatory gene expression. Moreover, B. lactis Ca360 reversed zinc deficiency–associated gut dysbiosis by reducing inflammation-related taxa and enriching Muribaculum, which was positively correlated with zinc status and antioxidant capacity. Overall, these findings demonstrate that B. lactis Ca360 combined with ZnSO4 effectively mitigates zinc deficiency–induced oxidative stress and intestinal dysfunction, highlighting its potential as a targeted probiotic strategy for managing zinc deficiency–related disorders.

Background/Objectives: Iron deficiency anemia (IDA) is a widespread nutritional disorder characterized by impaired iron absorption, inflammation-associated iron restriction, and disrupted iron homeostasis. Increasing evidence suggests that gut microbiota play an important role in iron metabolism; however, the mechanisms underlying probiotic-assisted iron supplementation remain unclear. Our research group previously conducted in vitro fermentation screening experiments and obtained a bacterial strain, B. lactis Ca360, which possesses iron absorption-enhancing activity. Methods: In this study, an IDA mouse model induced by a low-iron diet was used to investigate whether B. lactis Ca360 could synergistically improve iron metabolism when combined with iron supplementation. Mice were treated with FeSO₄ alone or FeSO₄ combined with B. lactis Ca360, and hematological parameters, organ indices, serum iron-related markers, histopathological changes, duodenal iron metabolism-related gene expression, hepatic inflammatory responses, gut microbiota composition, short-chain fatty acid (SCFA) levels, and correlation networks were analyzed. Results: Iron deficiency induced typical anemia phenotypes, multi-organ dysfunction, intestinal iron absorption dysregulation, hepatic inflammation, and gut microbiota dysbiosis. Compared with FeSO₄ alone, the combined intervention more effectively improved hematological parameters, reduced organ indices, restored liver and spleen histological integrity, normalized intestinal iron metabolism-related gene expression, and alleviated hepatic inflammation. In addition, B. lactis Ca360 markedly reshaped gut microbiota composition, enriching SCFA-producing anaerobic genera, including Ruminococcus, Roseburia, Acetatifactor, Intestinimonas, Eubacterium_coprostanoligenes_group_unclassified, and Oscillibacter, accompanied by increased acetate, propionate, and butyrate levels. Spearman correlation analysis further revealed close associations between gut microbiota remodeling, improved iron metabolism, reduced inflammatory status, and recovery of anemia-related phenotypes. Conclusions: Overall, these findings demonstrate that B. lactis Ca360 enhances the efficacy of iron supplementation by modulating SCFA-producing and anti-inflammatory gut microbiota, thereby coordinately regulating intestinal iron absorption, inflammation, and systemic iron homeostasis, supporting probiotic-assisted iron supplementation as a promising nutritional strategy for IDA management.

Background/Objectives: Obesity is closely associated with gut microbiota dysbiosis, intestinal barrier dysfunction, and impaired glucose and lipid metabolism. However, single probiotic or prebiotic interventions often yield only limited metabolic improvements. This study aimed to evaluate the effects of a synbiotic formulation comprising Lacto-N-tetraose (LNT) and Bifidobacterium animalis subsp. lactis MN-Gup (MN-Gup) in a high-fat diet (HFD)-induced obese mouse model. Methods: In this study, an HFD-induced obese mouse model was used to investigate whether the synbiotic formulation of LNT and MN-Gup could ameliorate obesity-related metabolic dysregulation, intestinal barrier dysfunction, and gut microbiota imbalance. Mice were treated with LNT alone, MN-Gup alone, or the synbiotic at different doses. Serum biochemical parameters, glucose tolerance, lipid profiles, liver histopathology, intestinal barrier markers, gut microbiota composition, short-chain fatty acid (SCFA) levels were analyzed. Results: High-dose synbiotic intervention significantly outperformed single-component treatments in reducing weight gain, improving glucose tolerance and lipid profiles, and attenuating hepatic lipid accumulation and injury in mice. These metabolic changes were accompanied by improved markers of intestinal barrier integrity and modulation of gut microbiota composition, characterized by the enrichment of beneficial genera (e.g., Akkermansia, Leuconostoc, and Alistipes) alongside a reduction in obesity-associated taxa (including Desulfovibrionaceae_unclassified, Colidextribacter, Helicobacter, Erysipelatoclostridium, Peptococcaceae_unclassified, and Firmicutes_unclassified). Spearman correlation analysis revealed associative links between microbial alterations and host metabolic markers. Conclusions: Collectively, these findings suggest that the synbiotic formulation comprising high-dose LNT and MN-Gup offers potential benefits for managing high-fat diet-induced metabolic dysregulation in mice.