Qing Ai

Objectives: This study investigated the potential beneficial effects of a probiotic candidate, Clostridium cochlearium 2316, in modulating physiological and metabolic markers in mice with high-fat diet-induced obesity (DIO). Methods: C57BL/6 DIO mice were assigned to three groups (ad libitum): standard low-fat control (LF, 10% fat), high-fat diet (HF, 60% fat), and high-fat diet supplemented with approximately one billion CFU/day of CC2316 via daily oral gavage for 16 weeks. Results: After 16 weeks, the CC group exhibited 17.3% lower body weight gain (p < 0.001) and significant fat mass decrease (p < 0.0001) compared to HF mice. Serum biochemistry showed that CC2316 supplementation resulted in a 27.7% reduction in fasting blood glucose (p < 0.05), a 58.4% reduction in fasting insulin (p < 0.01), and an 89.4% improvement in HOMA-IR score (p < 0.05). Furthermore, serum total cholesterol level decreased dramatically by 40.2% in the CC group (p < 0.001). Despite a higher caloric absorption rate (p < 0.001), CC mice demonstrated a significant beneficial shift in energy expenditure, characterized by an increased basal metabolic rate (p < 0.05), higher energy expenditure (p < 0.05), and an elevated respiratory quotient (RER) (p < 0.05), alongside increased physical activity (p < 0.05). Conclusions: This investigation strongly suggests that CC2316 supplementation mitigates the adverse effects of HFD-induced obesity by modulating whole-body energy metabolism, positioning it as a potential aid to lower risk factors associated with metabolic syndrome. The precise mechanisms linking the gut microbiome to altered energy substrate utilization are discussed and suggested for further investigation.

Background/Objectives: Ketogenic diets (KDs), defined by very low carbohydrate and high fat content, are widely studied for obesity and metabolic disease. However, KD formulations vary from 60–95% fat, leading to inconsistent induction of ketogenesis and variable outcomes. The fat threshold required for sustained ketosis, and the tissue-specific programs that mediate KD efficacy, remain unclear. Methods: We evaluated multiple KD formulations (80–95% fat) in C57BL/6J wild-type (WT) and diet-induced obese (DIO) mice. Plasma, hepatic, and intestinal β-hydroxybutyrate (BHB) were measured together with expression of ketogenesis and fatty acid oxidation genes. Body weight, adipose distribution, and liver morphology were assessed under both direct feeding and therapeutic settings. Results: In WT mice, only diets exceeding 85% fat induced robust ketogenesis, reflected by elevated BHB and hepatic upregulation of Cd36, Cpt1a, Acat1, and Hmgcs2. Moderate KDs (80–85%) failed to trigger ketosis and resembled high-fat feeding. In obese mice, an 80% KD lowered fasting glucose without reducing body weight, whereas a 90% KD promoted systemic ketosis, weight loss, and adipose reduction. Interestingly, hepatic transcriptional programs for fatty acid oxidation and ketogenesis were suppressed under 90% KD despite elevated BHB, suggesting reliance on substrate availability and peripheral utilization. In contrast, intestinal Hmgcs2 was strongly induced in both WT and DIO mice, with Oxct1 upregulated only in obesity, indicating local ketone production and consumption. Conclusions: These findings identify > 85% dietary fat as a threshold for sustained ketosis and highlight distinct liver–intestine contributions, underscoring ketogenesis as the central driver of KD’s anti-obesity benefits.

Purpose Probiotic species of butyrate producers have been investigated for the potential in preventing and treating obesity and overweight. However, Clostridium cochlearium has not been linked with any health benefits. We hypothesized that C. cochlearium could be a promising new probiotic with health benefits in improving body weight control and insulin sensitivity. Methods Productions of short-chain fatty acids (SCFAs) were characterized for C. cochlearium by NMR and GC–MS analyses. Probiotic effects of C. cochlearium were evaluated through diet-induced obese (DIO) C57BL/6 mice. The influence of C. cochlearium administration on gut SCFAs was measured using GC–MS. LC–MS-based untargeted metabolomic profiling and multivariate analysis were used to assess the serum metabolic alteration, identify biomarkers and pathways in response to the C. cochlearium administration. Results After 17 weeks of diet intervention, body weight gain of CC group (fed with a high-fat diet supplemented with C. cochlearium) showed a 21.86% reduction from the high-fat diet (HF) control group (P < 0.001), which was specifically reflected on the significantly lowered fat mass (CC vs HF, 17.19 g vs 22.86 g, P < 0.0001) and fat percentage (CC vs HF, 41.25% vs 47.10%, P < 0.0001), and increased lean percentage (CC vs HF, 46.63% vs 43.72%, P < 0.05). C. cochlearium administration significantly reduced fasting blood glucose from week 8 (P < 0.05 or 0.01), and eventually improved insulin sensitivity (HOMA-IR, CC vs HF, 63.77 vs 143.13, P < 0.05). Overall lowered levels of SCFAs were observed in the gut content of CC group. Metabolomic analysis enabled the identification of 53 discriminatory metabolites and 24 altered pathways between CC and HF groups. In particularly, most of the pathway-matched metabolites showed positive correlations with body weight, which included glutamate, phenylalanine, ornithine, PCs, LPCs, AcCas, proline, 5,6-dihydrouracil, pyroglutamic acid, and 1-pyrroline-4-hydroxy-2-carboxylate. Conclusions The beneficial effects of C. cochlearium could be related to its ability to restore certain obesity-driven biomarkers and pathways, especially downregulating pathways related to specific amino acids, PCs, LPCs and AcCas. Further research is warranted to investigate related metabolites and metabolic pathways. C. cochlearium may be developed as a promising new probiotic for the prevention or alleviation of obesity and diabetes in human.

The mechanism of avian navigation is an important question for global scientists. One of the most famous candidates is the radical pair mechanism (RPM), which shows that avian navigation is achieved by detecting the amount of products from chemical reactions, which exhibit different properties for singlet and triplet spin states. Based on the theory, we explore the amount of the the singlet recombination product by changing the coupling strength and direction of the magnetic field. The radical pair in our model is coupled with a Lipkin-Meshkov-Glick (LMG) bath, which proposes attractive results at quantum phase transition (QPT) point, especially when the magnetic field is parallel with the original direction of the pair. We find weakest navigation ability in QPT point according to one of our proposing methods. And we find invariant subspace in our Hamiltonian when the magnetic field is vertical to the plane of the radical pair and the bath, which will greatly speed up our calculation. Our results could help the exploration of the design principle of artificial avian navigation.

English cross-cultural communication learning is an important part of English teaching. Improving the teaching quality of English cross-cultural communication is conducive to improving students’ interest in Learning English. This paper firstly explains the deficiencies of English cross-cultural communication learning and the characteristics of network education and multimedia education, and at the same time discusses the study of English cross-cultural communication carried out by computer technology for readers’ reference.

An extract of noni (Morinda citrifolia) fruits has shown potent inhibitory activity on gut bacterial β-glucuronidase, which could help reduce irinotecan-induced diarrhea. In this study, four bacterial β-glucuronidase inhibitors were obtained following bioactive assay-guided isolation, including two sesquineolignans, (7S,8S,7′R,8′R)-isoamericanol B (1) and americanol B (2), and two dineolignans, moricitrins A (3) and B (4). Compounds 2–4 are new, and the absolute configuration of compound 1 was determined for the first time. Their chemical structures were elucidated through HRESIMS and NMR spectra, and their absolute configurations were established via the comparison of the experimental and calculated electronic circular dichroism spectra. These compounds showed potent inhibition against gut bacterial β-glucuronidase with IC₅₀ values in the range 0.62–6.91 μM. The inhibition presented specificity for β-glucuronidase, as all the compounds showed no or weak effects on digestive enzymes such as α-amylase, α-glucosidase, and lipase, suggesting that their gastrointestinal side effects could be minimized. These specific inhibitors as naturally occurring dietary compounds may be developed as promising candidates to alleviate irinotecan-induced diarrhea.

The 16S rDNA polymerase chain reaction (PCR)-denaturing gradient gel electrophoresis (DGGE) and sequencing method has been demonstrated to be valuable in detecting pathogens in the blood of patients suffering from fever or neutropenia. However, its use in the diagnosis of neonatal late‑onset septicemia (LOS) has not yet been reported. The aim of the present study was to investigate the efficiency of this method in detection of the type of bacterial infection in neonatal LOS. Blood specimens from 60 neonates in whom LOS was suspected were collected. Fourteen culture positive blood samples and 24 spiked 'infected' blood samples were analyzed by the 16S rDNA PCR‑DGGE and sequencing method or by pathogen‑specific PCR. Only in 5 of the 14 cases did the results of 16S rDNA PCR‑DGGE and sequencing match with the results of blood culturing. In the other 9 cases, the blood culture failed to detect bacteria, such as Neisseria sp. and Moraxella sp., which were detected by 16S rDNA PCR‑DGGE and sequencing. Furthermore, the 16S rDNA PCR‑DGGE and sequencing failed to detect blood culture‑proven bacteria, such as Klebsiella pneumonia. A competitive inhibitory effect in 16S rDNA PCR amplification may lead to the discrepancy between pathogen‑specific PCR and spiked 'infected' blood samples. When a certain species of bacteria was detected by 16S rDNA PCR, the competitive inhibitory effect presented a higher sensitivity in detecting this species in the blood samples that contained bacterial DNA only from this species compared with the blood samples that were blended with other bacterial DNAs. In conclusion, 16S rDNA PCR‑DGGE and sequencing can detect a more comprehensive spectrum of pathogens than blood culture. However, the competitive inhibitory effect, which may lead to false negative results should be taken into consideration when the 16S rDNA PCR-DGGE and sequencing method is applied to the diagnosis of neonatal LOS.