Intestinal microflora promotes Th2-mediated immunity through NLRP3 in damp and heat environments.

Background: With the worsening of the greenhouse effect, the correlation between the damp-heat environment (DH) and the incidence of various diseases has gained increasing attention. Previous studies have demonstrated that DH can lead to intestinal disorders, enteritis, and an up-regulation of NOD-like receptor protein 3 (NLRP3). However, the mechanism of NLRP3 in this process remains unclear. Methods: We established a DH animal model to observe the impact of a high temperature and humidity environment on the mice. We sequenced the 16S rRNA of mouse feces, and the RNA transcriptome of intestinal tissue, as well as the levels of cytokines including interferon (IFN)-γ and interleukin (IL)-4 in serum. Results: Our results indicate that the intestinal macrophage infiltration and the expression of inflammatory genes were increased in mice challenged with DH for 14 days, while the M2 macrophages were decreased in Nlrp3 -/- mice. The alpha diversity of intestinal bacteria in Nlrp3 -/- mice was significantly higher than that in control mice, including an up-regulation of the Firmicutes/Bacteroidetes ratio. Transcriptomic analysis revealed 307 differentially expressed genes were decreased in Nlrp3 -/- mice compared with control mice, which was related to humoral immune response, complement activation, phagocytic recognition, malaria and inflammatory bowel disease. The ratio of IFN-γ/IL-4 was decreased in control mice but increased in Nlrp3 -/- mice. Conclusions: Our study found that the inflammation induced by DH promotes Th2-mediated immunity via NLRP3, which is closely related to the disruption of intestinal flora.

Distinct microbiome of tongue coating and gut in type 2 diabetes with yellow tongue coating.

The gut microbiome plays a critical role in the pathogenesis of type 2 diabetes mellitus (T2DM). However, the inconvenience of obtaining fecal samples hinders the clinical application of gut microbiome analysis. In this study, we hypothesized that tongue coating color is associated with the severity of T2DM. Therefore, we aimed to compare tongue coating, gut microbiomes, and various clinical parameters between patients with T2DM with yellow (YC) and non-yellow tongue coatings (NYC). Tongue coating and gut microbiomes of 27 patients with T2DM (13 with YC and 14 with NYC) were analyzed using 16S rDNA gene sequencing technology. Additionally, we measured glycated hemoglobin (HbA1c), random blood glucose (RBG), fasting blood glucose (FBG), postprandial blood glucose (PBG), insulin (INS), glucagon (GC), body mass index (BMI), and homeostasis model assessment of ß-cell function (HOMA-ß) levels for each patient. The correlation between tongue coating and the gut microbiomes was also analyzed. Our findings provide evidence that the levels of Lactobacillus spp. are significantly higher in both the tongue coating and the gut microbiomes of patients with YC. Additionally, we observed that elevated INS and GC levels, along with decreased BMI and HOMA-ß levels, were indicative of a more severe condition in patients with T2DM with YC. Moreover, our results suggest that the composition of the tongue coating may reflect the presence of Lactobacillus spp. in the gut. These results provide insights regarding the potential relationship between tongue coating color, the gut microbiome, and T2DM.

Gut microbiota associated with appetite suppression in high-temperature and high-humidity environments.

BACKGROUND: Food is crucial for maintaining vital human and animal activities. Disorders in appetite control can lead to various metabolic disturbances. Alterations in the gut microbial composition can affect appetite and energy metabolism. While alterations in the gut microbiota have been observed in high-temperature and high-humidity (HTH) environments, the relationship between the gut microbiota during HTH and appetite remains unclear. METHODS: We utilised an artificial climate box to mimic HTH environments, and established a faecal bacteria transplantation (FMT) mouse model. Mendelian randomisation (MR) analysis was used to further confirm the causal relationship between gut microbiota and appetite or appetite-related hormones. FINDINGS: We found that, in the eighth week of exposure to HTH environments, mice showed a decrease in food intake and body weight, and there were significant changes in the intestinal microbiota compared to the control group. After FMT, we observed similar changes in food intake, body weight, and gut bacteria. Appetite-related hormones, including ghrelin, glucagon-like peptide-1, and insulin, were reduced in DH (mice exposed to HTH conditions) and DHF (FMT from mice exposed to HTH environments for 8 weeks), while the level of peptide YY initially increased and then decreased in DH and increased after FMT. Moreover, MR analysis further confirmed that these changes in the intestinal microbiota could affect appetite or appetite-related hormones. INTERPRETATION: Together, our data suggest that the gut microbiota is closely associated with appetite suppression in HTH. These findings provide novel insights into the effects of HTH on appetite. FUNDING: This work was supported by the National Natural Science Foundation of China and Guangzhou University of Chinese Medicine.

[Flux Characteristics of CO2, CH4, and N2 O and their Influencing Factors in Different Types of Ditches on the Chengdu Plain].

In order to study the flux characteristics of CH4, CO2 and N2O in different ditches and their influencing factors, three types of ditches (an agricultural ditch, agricultural-living compound ditch, and living ditch) were monitored once a month from March 2014 to February 2015 using static floating chambers in the Chengdu Plain. The results showed that:① Affected by human activities, CO2, CH4, and N2O fluxes were high in ditches and ranged from -2.26-1504.40 mg·(m2·h)-1, 0.69-40.00 mg·(m2·h)-1, and -2.27-70.35 µg·(m2·h)-1,respectively. All are higher in summer compared to autumn and spring, and are lowest in winter. ② The flux of CO2 in agricultural-living compound ditches was significantly higher than that in agricultural ditches and living ditches (P<0.05), and the fluxes of CH4 and N2O in living ditches were significantly higher than those in agricultural ditches and agricultural-living compound ditches (P<0.05). ③ Water temperature and rainfall were the main environmental factors affecting CO2, CH4, and N2O fluxes, and DO (dissolved oxygen) and TN (total nitrogen) were the main environmental factors affecting CO2 and N2O fluxes. NH4+-N (ammonium nitrogen) and DO were the main water quality parameters affecting the CH4 flux.