Lactobacillus plantarum ZJUFB2 Prevents High Fat Diet-Induced Insulin Resistance in Association With Modulation of the Gut Microbiota

Lactiplantibacillus plantarum 1008 Enhances Testicular Function and Spermatogenesis via the Modulation of Gut Microbiota in Male Mice with High-Fat-Diet-Induced Obesity

Our study was designed to investigate the Lactiplantibacillus plantarum 1008 (LP1008) on testicular antioxidant capacity, spermatogenesis, apoptosis, autophagy, and metabolic function in male mice with high-fat-diet-induced obesity. A total of thirty-six male C57BL/6 mice were fed a normal diet (denoted as the NC group) or a high-fat control diet (denoted as the HFC group) for 16 weeks, then half of the HFC group was randomly chosen and subsequently fed with LP1008 for the final 8 weeks (high-fat diet + LP1008; denoted as the HFP group). The HFP group expressed improved blood cholesterol, insulin resistance, hepatic function, and lipopolysaccharide (LPS) levels compared to the HFC group. Meanwhile, the HFC group displayed decreased testicular testosterone levels, sperm quality, and 17β-HSD protein expression, which were rescued after LP1008 treatment. Moreover, the HFC group had lower superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPX) enzyme activities. After LP1008 treatment, enhanced antioxidative activities and decreased lipid peroxidation were observed. The HFC group also exhibited aggravated apoptosis, inflammation, and autophagy proteins in the testis, which were ameliorated by LP1008 supplementation. Furthermore, the gut microbiota analysis results revealed that the Firmicutes/Bacteroidetes ratio was significantly elevated in the HFC and HFP groups compared to the NC group and that LP1008 treatment diminished Ruminococcaceae and enhanced Bifidobacteriaceae diversity. In summary, LP1008 treatment strengthened antioxidative enzyme levels and regulated microbiota-ameliorated HFC-induced oxidative stress, apoptosis, inflammation, and autophagy, and thus improved testicular function and semen quality.

Gut bacteria: an etiological agent in human pathological conditions

Through complex interactions with the host's immune and physiological systems, gut bacteria play a critical role as etiological agents in a variety of human diseases, having an impact that extends beyond their mere presence and affects the onset, progression, and severity of the disease. Gaining a comprehensive understanding of these microbial interactions is crucial to improving our understanding of disease pathogenesis and creating tailored treatment methods. Correcting microbial imbalances may open new avenues for disease prevention and treatment approaches, according to preliminary data. The gut microbiota exerts an integral part in the pathogenesis of numerous health conditions, including metabolic, neurological, renal, cardiovascular, and gastrointestinal problems as well as COVID-19, according to recent studies. The crucial significance of the microbiome in disease pathogenesis is highlighted by this role, which is comparable to that of hereditary variables. This review investigates the etiological contributions of the gut microbiome to human diseases, its interactions with the host, and the development of prospective therapeutic approaches. To fully harness the benefits of gut microbiome dynamics for improving human health, future research should address existing methodological challenges and deepen our knowledge of microbial interactions.

Effects of Lactobacillus plantarum supplementation on glucose and lipid metabolism in type 2 diabetes mellitus and prediabetes: A systematic review and meta-analysis of randomized controlled trials

Lactobacillus plantarum has been shown to improve glucose and lipid metabolism in mouse models of type 2 diabetes mellitus (T2DM). However, it remains unclear whether such benefits extend to humans. A systematic review and meta-analysis of randomized controlled trials (RCTs) was performed to clarify the effect of L. plantarum supplementation on glucose and lipid metabolism in T2DM and prediabetes. The PubMed, Cochrane, and Web of Science databases were searched. A random-effects model was used to estimate the pooled mean difference with 95% CI (confidence interval). L. plantarum supplementation reduced the levels of fasting plasma glucose (-0.41, 95%CI -0.63, -0.19 mg/dL; n = 5) and hemoglobin A1c (-0.2, 95%CI: -0.3, 0%; n = 4). A non-statistically significant tendency towards improvements in the Homeostatic Model Assessment for Insulin Resistance (MD: -0.74, 95%CI: -1.72, 0.25; n = 3), low-density lipoprotein cholesterol (-6.87; 95%CI: -15.03, 1.29 mg/dL; n = 3), high-density lipoprotein cholesterol (MD: 1.34; 95%CI: -0.78, 3.46 mg/dL; n = 3), triglyceride (MD: -3.90; 95%CI: -11.05, 3.24 mg/dL; n = 3), and total cholesterol (MD: -4.88; 95%CI: -11.84, 2.07 mg/dL; n = 3) was observed with the supplementation. In summary, while the evidence from the currently available RCTs provides a crude indication that L. plantarum supplementation might improve glucose and lipid metabolism in patients with T2DM and prediabetes, the benefits of the supplementation are likely subtle, and its clinical significance requires further investigation.

Applied microbiology of the phyllosphere

The phyllosphere, or plant leaf surface, represents a microbial ecosystem of considerable size, holding extraordinary biodiversity and enormous potential for the discovery of new products, tools, and applications in biotechnology, agriculture, medicine, and elsewhere. This mini-review highlights the applied microbiology of the phyllosphere as an original field of study concerning itself with the genes, gene products, natural compounds, and traits that underlie phyllosphere-specific adaptations and services that have commercial and economic value for current or future innovation. Examples include plant-growth-promoting and disease-suppressive phyllobacteria, probiotics and fermented foods that support human health, as well as microbials that remedy foliar contamination with airborne pollutants, residual pesticides, or plastics. Phyllosphere microbes promote plant biomass conversion into compost, renewable energy, animal feed, or fiber. They produce foodstuffs such as thickening agents and sugar substitutes, industrial-grade biosurfactants, novel antibiotics and cancer drugs, as well as enzymes used as food additives or freezing agents. Furthermore, new developments in DNA sequence-based profiling of leaf-associated microbial communities allow for surveillance approaches in the context of food safety and security, for example, to detect enteric human pathogens on leafy greens, predict plant disease outbreaks, and intercept plant pathogens and pests on internationally traded goods. KEY POINTS: • Applied phyllosphere microbiology concerns leaf-specific adaptations for economic value • Phyllobioprospecting searches the phyllosphere microbiome for product development • Phyllobiomonitoring tracks phyllosphere microbial profiles for early risk detection.

Probiotics in the Sourdough Bread Fermentation: Current Status

Sourdough fermentation is an ancient technique to ferment cereal flour that improves bread quality, bringing nutritional and health benefits. The fermented dough has a complex microbiome composed mainly of lactic acid bacteria and yeasts. During fermentation, the production of metabolites and chemical reactions occur, giving the product unique characteristics and a high sensory quality. Mastery of fermentation allows adjustment of gluten levels, delaying starch digestibility, and increasing the bio-accessibility of vitamins and minerals. This review focuses on the main steps of sourdough fermentation, the microorganisms involved, and advances in bread production with functional properties. The impact of probiotics on human health, the metabolites produced, and the main microbial enzymes used in the bakery industry are also discussed.

Brevibacillus laterosporus BL1, a promising probiotic, prevents obesity and modulates gut microbiota in mice fed a high-fat diet

Scope

Probiotics are a potential preventive strategy for obesity. However, with discrete efficacy and limited species of probiotics, there is a demand for novel strains with excellent anti-obesity properties. This study aimed to investigate the effects of Brevibacillus laterosporus BL1 on preventing obesity in high-fat diet (HFD)-fed mice.

Methods and results

C57BL/6 male mice were randomly assigned to four groups (n = 10) and fed a control diet, HFD, HFD plus B. laterosporus BL1, and HFD plus supernatant of B. laterosporus BL1, respectively for 8 weeks. The results showed that prophylactic B. laterosporus BL1 treatment reduced body weight gain by 41.26% in comparison to the HFD group, and this difference was accompanied by a reduction in body fat mass and the weight of inguinal white adipose tissues and epididymal white adipose tissue (-33.39%, -39.07%, and -43.75%, respectively). Moreover, the B. laterosporus BL1-mediated improvements in lipid profile, insulin resistance, and chronic inflammation were associated with the regulation of gene expression related to lipid metabolism and enhancement of brown adipose tissue thermogenesis. Particularly, B. laterosporus BL1 intervention significantly improved HFD-induced gut flora dysbiosis, as evidenced by a reverse in the relative abundance of Bacillota and Bacteroidota, as well as an increase in the relative abundance of bacteria that produce short-chain fatty acids (SCFAs), which in turn increased SCFAs levels.

Conclusion

Our findings found for the first time that B. laterosporus BL1 may be a promising probiotic for prevention of obesity associated with the regulation of gut microbiota.

Mouse feeding study and microbiome analysis of sourdough bread for evaluation of its health effects

Sourdough bread fermented with yeast and lactic acid bacteria (LAB) is thought to have various beneficial health effects. However, its beneficial effects were not fully evaluated with in vivo mouse model. To evaluate these effects in vivo, a mouse feeding study and microbiome analysis of white bread containing 40% sourdough (WBS) and yeast-leavened white bread (WB) were performed. Although feed consumption and body weight increased with WBS, the glycemic index was reduced, suggesting a diabetes-lowering effect, probably due to the presence of dietary fiber and short-chain fatty acids (SCFA). In addition, a mineral absorption test showed that WBS increased magnesium absorption owing to phytate degradation during fermentation. Interestingly, WBS decreased total cholesterol and triglycerides, probably due to the dietary fiber and SCFA in LAB. In addition, the ratio of low- and high-density lipoprotein was decreased in WBS, implying potential risk reduction for cardiovascular disease. An immunomodulatory assay of WBS revealed that pro-inflammatory cytokines TNF-α and IL-6 were decreased, suggesting anti-inflammatory activity. Gluten degradation by fermentation and antioxidation activity of menaquinol/ubiquinol by gut microbiota also supported the anti-inflammatory activity of sourdough bread. Furthermore, some beneficial gut bacteria, including Akkermansia, Bifidobacterium, and Lactobacillus, were increased in WBS. In particular, Akkermansia has been associated with anti-inflammatory properties. Consequently, WBS has beneficial effects on health, including decreased glycemic index and cholesterol, increased mineral availability and absorption, anti-inflammatory properties, and establishment of healthy gut microbiota.

Evaluation of Hypoglycemic and Antioxidant Activities of Soybean Meal Products Fermented by Lactobacillus plantarum FPS 2520 and Bacillus subtilis N1 in Rats Fed with High-Fat Diet

The hypoglycemic and antioxidant activities of Lactobacillus plantarum FPS 2520 and/or Bacillus subtilis N1 fermented soybean meal (SBM) in rats fed a high-fat diet (HFD) were investigated by assessing plasma glucose levels, insulin resistance, and oxidative stress-induced organ damage. Supplementation with FPS 2520- and/or N1-fermented SBM (500 and 1000 mg/kg of body weight per day) to HFD-induced obese rats for 6 weeks significantly down-regulated the concentration of plasma glucose during the oral glucose tolerance test (OGTT), as well as the concentration of fasting plasma glucose, insulin, and the value of the homeostasis model assessment of insulin resistance (HOMA-IR). In addition, plasma and hepatic levels of malondialdehyde (MDA) were alleviated in rats fed fermented SBM, especially SBM fermented by mixed strains. Moreover, fermented SBM treatment reduced HFD-exacerbated increases in plasma aspartate aminotransferase (AST), alanine aminotransferase (ALT), creatinine, and uric acid levels. Based on these results, we clearly demonstrate the effect of fermented SBM on improving insulin resistance and oxidation-induced organ damage. Therefore, it is suggested that fermented SBM has the potential to be developed as functional foods for the management of obesity-induced hyperglycemia and organ damage.