Lacticaseibacillus rhamnosus Probio-M9-Driven Mouse Mammary Tumor-Inhibitory Effect Is Accompanied by Modulation of Host Gut Microbiota, Immunity, and Serum Metabolome

Gut microbiota and metabolic profiles in chronic intermittent hypoxia-induced rats: disease-associated dysbiosis and metabolic disturbances

Aim

Chronic intermittent hypoxia (CIH) is a key characteristic of obstructive sleep apnea (OSA) syndrome, a chronic respiratory disorder. The mechanisms of CIH-induced metabolic disturbance and histopathological damage remain unclear.

Methods

CIH-induced rats underwent daily 8-h CIH, characterized by oxygen levels decreasing from 21% to 8.5% over 4 min, remaining for 2 min, and quickly returning to 21% for 1 min. The control rats received a continuous 21% oxygen supply. The levels of hypersensitive C reactive protein (h-CRP), tumor necrosis factor-α (TNF-α), interleukin 6 (IL-6), interleukin 8 (IL-8), and nuclear factor kappa-B (NF-κB) were measured by ELISA. Histological analysis of the soft palates was conducted using HE staining. The microbial profiling of fecal samples was carried out by Accu16STM assay. Untargeted metabolomics of serum and soft palate tissue samples were analyzed by UPLC-MS. The protein expression of cAMP-related pathways in the soft palate was determined by Western blot.

Results

After 28 h of CIH induction, a significant increase in pro-inflammatory cytokines was observed in the serum, along with mucosal layer thickening and soft palate tissue hypertrophy. CIH induction altered the diversity and composition of fecal microbiota, specifically reducing beneficial bacteria while increasing harmful bacteria/opportunistic pathogens. Notably, CIH induction led to a significant enrichment of genera such as Dorea, Oscillibacter, Enteractinococcus, Paenibacillus, Globicatella, and Flaviflexus genera. Meanwhile, Additionally, CIH induction had a notable impact on 108 serum marker metabolites. These marker metabolites, primarily involving amino acids, organic acids, and a limited number of flavonoids or sterols, were associated with protein transport, digestion and absorption, amino acid synthesis and metabolism, as well as cancer development. Furthermore, these differential serum metabolites significantly affected 175 differential metabolites in soft palate tissue, mainly related to cancer development, signaling pathways, amino acid metabolism, nucleotide precursor or intermediate metabolism, respiratory processes, and disease. Importantly, CIH induction could significantly affect the expression of the cAMP pathway in soft palate tissue.

Conclusions

Our findings suggest that targeting differential metabolites in serum and soft palate tissue may represent a new approach to clinical intervention and treatment of OSA simulated by the CIH.

Probiotics Bifidobacterium lactis M8 and Lactobacillus rhamnosus M9 prevent high blood pressure via modulating the gut microbiota composition and host metabolic products

IMPORTANCE

Elevated blood pressure affects 40% of the adult population, which accounts for high cardiovascular disease risk and further high mortality yearly. The global understanding of the gut microbiome for hypertension may provide important insights into the prevention. Bifidobacterium lactis M8 and Lactobacillus rhamnosus M9 originated from human breast milk, were able to decrease blood pressure, and modified metabolites in a high fructose-induced elevated blood pressure mouse model. Moreover, we found there was a close relationship between unexplored gut microbes and elevated blood pressure. Also, subsequently, the cross-link was explored among gut microbes, metabolites, and some metabolic pathways in gut microbial environment through introducing novel prediction methodology and bioinformatic analysis. It allowed us to hypothesize that probiotics can prevent elevated blood pressure via gut microbiota and related metabolism.Thus, utilization of dietary strategies (such as probiotics) to maintain the blood pressure level is of crucial importance.

Lactobacillus rhamnosus Probio-M9 alleviates OVA-sensitized food allergy through modulating gut microbiota and its metabolism

Over the past few decades, food allergy has continued to rise, significantly affecting our health, economy, and quality of life. However, current therapeutic strategies have limited efficacy and need to be improved. One alternative to prevent or reduce allergies is to modulate immunity and microbiota. Human milk (HM) could be considered a protective factor against food allergy, but how probiotics in human milk impact the susceptibility to food allergy remains unknown. Therefore, we studied the preventive impact of human milk Lactobacillus rhamnosus Probio-M9 on food allergy in ovalbumin (OVA)-sensitized mice. We studied the effects of oral administration of Probio-M9 on allergic signatures, immune response, gut microbiota, and metabolism. Oral therapeutic administration of live Probio-M9, but not heat-killed Probio-M9, significantly reduces OVA-specific IgE (OVA-sIgE), histamine, and mMCP-1 (mouse mast cell protease-1) levels in OVA-sensitized mice. Moreover, Probio-M9 supplementation reduced allergic inflammation and changes in the Th2/Th1 balance toward a dampened Th2 response. 16S rDNA sequencing analysis revealed an increased ratio of Firmicutes/Bacteroidota (F/B) and the relative abundance of short-chain fatty acid (SCFA)-producing Clostridia in the feces after Probio-M9 intake. Simultaneously, Probio-M9 significantly increased the levels of SCFAs and promoted the phosphorylation of signal transducer and activator of transcription 3 (STAT3), thereby inducing the expression of the antimicrobial peptides (AMPs) Reg3b and Reg3g. Our findings suggest that the use of Probio-M9 can be a potent strategy in food allergy prevention.

Probiotics alleviate constipation and inflammation in late gestating and lactating sows

Constipation and systemic inflammation are common in late pregnant and lactating sows, which cause health problems like uteritis, mastitis, dystocia, or even stillbirth, further influencing piglets' survival and growth. Probiotic supplementation can improve such issues, but the beneficial mechanism of relieving constipation and enhancing gut motility remains underexplored. This study aimed to investigate the effects and mechanism of probiotic supplementation in drinking water to late pregnant sows on constipation, inflammation, and piglets' growth performance. Seventy-four sows were randomly allocated to probiotic (n = 36) and control (n = 38) groups. Probiotic treatment significantly relieved sow constipation, enhanced serum IL-4 and IL-10 levels while reducing serum IL-1β, IL-12p40, and TNF-α levels, and increased piglet daily gain and weaning weight. Furthermore, probiotic administration reshaped the sow gut bacteriome and phageome structure/diversity, accompanied by increases in some potentially beneficial bacteria. At 113 days of gestation, the probiotic group was enriched in several gut microbial bioactive metabolites, multiple carbohydrate-active enzymes that degrade pectin and starch, fecal butyrate and acetate, and some serum metabolites involved in vitamin and amino acid metabolism. Our integrated correlation network analysis revealed that the alleviation of constipation and inflammation was associated with changes in the sow gut bacteriome, phageome, bioactive metabolic potential, and metabolism.

Complex probiotics alleviate ampicillin-induced antibiotic-associated diarrhea in mice

Aim

Antibiotic-associated diarrhea (AAD) is a common side effect during antibiotic treatment, which can cause dysbacteriosis of the gut microbiota. Previous studies have shown beneficial effects in AAD treatment with Bifidobacterium lactis XLTG11, Lactobacillus casei Zhang, Lactobacillus plantarum CCFM8661, and Lactobacillus rhamnosus Probio-M9. However, no studies have been conducted on the immunomodulatory effects and protective intestinal barrier function of four complex probiotics. The aim of our study is to investigate the alleviation effects of complex probiotics on ampicillin-induced AAD.

Methods

Thirty-six BALB/c mice were randomly divided into six groups: normal control group (NC), model control group (MC), low-, medium-, and high-dose probiotics groups (LD, MD, and HD), and positive drug (Bifico, 1 × 10⁷ cfu) control group (PDC; Bifico, also known as Bifidobacterium Triple Live Capsule, is composed of Bifidobacterium longum, Lactobacillus acidophilus, and Enterococcus faecalis). An AAD model was established by intragastric administration of ampicillin, by gavage of different doses of complex probiotics and Bifico. The weight gain, fecal water content, loose stool grade, intestinal permeability, total protein and albumin levels, intestinal barrier, cytokine levels, and gut microbiota were determined.

Results

The results showed that complex probiotics significantly decreased the fecal water content, loose stool grade, intestinal permeability, and ileum tissue damage. Their application increased the weight gain, SIgA, TP, and ALB levels. Additionally, complex probiotics significantly decreased the levels of pro-inflammatory cytokines and increased those of anti-inflammatory cytokines. Meanwhile, the mRNA expression levels of ZO-1, occludin, claudin-1, and MUC2 were significantly upregulated in the probiotic-treated group. Furthermore, the complex probiotics increased the gut microbiota diversity and modulated the changes in the gut microbiota composition caused by ampicillin. At the phylum level, the abundance of Proteobacteria in the HD group was lower than that in the MC group, whereas that of Bacteroidetes was higher. At the genus level, the abundances of Klebsiella and Parabacteroides in the HD group were lower, whereas those of Bacteroides, Muribaculaceae, and Lactobacillus were higher than those in the MC group. Moreover, Spearman's correlation analysis also found that several specific gut microbiota were significantly correlated with AAD-related indicators.

Conclusion

We found that complex probiotics improved the diarrhea-related indexes, regulated gut microbiota composition and diversity, increased the expression levels of intestinal protective barrier-related genes, preserved the intestinal barrier function, and relieved inflammation and intestinal injury, thereby effectively improving AAD-associated symptoms. Graphical Abstract.