Cong Liang

Aim: The intestinal microbiota contributes to infant's intestine homeostasis. This study aimed to analyse how probiotics derived from breast milk promote infant intestinal development in rat pups. Methods and results: The effect of potential probiotics derived from breast milk on development of intrauterine growth retardation (IUGR) newborn rats' intestine was investigated. Limosilactobacillus oris ML-329 and Lacticaseibacillus paracasei ML-446 exhibited good hydrophobicity percentages (p < 0.05). ML-446 showed a significant effect on intestinal length and weight (p < 0.05). Meanwhile, the villus height of the IUGR newborn rats fed with ML-329 was significantly higher compared with those fed with Lacticaseibacillus rhamnosus GG (p < 0.05). Moreover, ML-329 and ML-446 both significantly stimulated the proliferation and differentiation of intestinal epithelial cells by increasing the number of ki67-positive cells, goblet cells, and lysozyme-positive Paneth cells (p < 0.05) through Wnt and Notch pathway. Conclusions: The proliferation and differentiation stimulating effects of ML-329 and ML-446 on IECs in the jejunum, ileum, and colon were mediated by activating the Wnt pathway with increased expression of wnt, lrp5, and β-catenin genes and accumulation of β-catenin, and by downregulating the Notch signalling pathway with decreased expression of the activated notch protein. Significance and Impact of the Study: Lactobacillus could facilitate IUGR rat pups' intestinal development and enhance the proliferation of Paneth cells and goblet cells. These findings provide further insights into promotion of the intestinal development by breast milk-derived beneficial microbes in early life of the IUGR newborn rats.

Scope: Many infants suffer from complementary feeding‐induced diarrhea (CFID). Studies have shown that intestinal microbes can enhance the intestinal barrier and prevent diarrhea by producing indole derivatives that promote pregnane X receptor (PXR) expression.Methods and Results: In this study, the indole test and determination of the PXR concentration are performed on tryptophan broth cultures of 320‐suspected Lactobacillus and Enterococcus strains. Four strains that produce indole derivatives that promote the expression of PXR are screened as potential functional probiotics. Both Lactobacillus rhamnosus MN‐431 (L. rhamnosus MN‐431) and Lactobacillus oris FN‐448 (L. oris FN‐448) can colonize the intestine of rat pups, and L. rhamnosus MN‐431 can significantly decrease the incidence of diarrhea and intestinal permeability in rat pups. Using real‐time qPCR and the analysis of the intestinal morphology using immunohistochemistry, it is observed that the metabolized tryptophan from L. rhamnosus MN‐431 can reduce small intestinal mucosal damage by stimulating PXR/NF‐κB signaling and activating PXR and aryl hydrocarbon receptor. The intestinal barrier is also enhanced by promoting the expression of tight junction proteins such as Occludin and zonula occludens‐1 in baby rats.Conclusion: The results demonstrate that L. rhamnosus MN‐431 can metabolize tryptophan to prevent infantile CFID by promoting the expression of PXR.

Scope: Obesity is a common disease worldwide and there is an urgent need for strategies to preventing obesity.Methods and Results: The anti‐obesity effect and mechanism of Ligilactobacillus salivarius LCK11 (LCK11) is studied using a C57BL/6J male mouse model in which obesity is induced by a high‐fat diet (HFD). Results show that LCK11 can prevent HFD‐induced obesity, reflected as inhibited body weight gain, abdominal and liver fat accumulation and dyslipidemia. Analysis of its mechanism shows that on the one hand, LCK11 can inhibit food intake through significantly improving the transcriptional and translational levels of peptide YY (PYY) in the rectum, in addition to the eventual serum PYY level; this is attributed to the activation of the toll‐like receptor 2/nuclear factor‑κB signaling pathway in enteroendocrine L cells by the peptidoglycan of LCK11. On the other hand, LCK11 supplementation effectively reduces the Firmicutes/Bacteroidetes ratio and shifts the overall structure of the HFD‐disrupted gut microbiota toward that of mice fed on a low‐fat diet; this also contributes to preventing obesity.Conclusion: LCK11 shows the potential to be used as a novel probiotic for preventing obesity by both promoting PYY secretion to inhibit food intake and regulating gut microbiota.

Despite the health benefits of Vitis vinifera L. leaves, its anti-obesity potential has not been fully explored. In this work, we showed that Vitis vinifera L. leaf extract (VLE) inhibits the pancreatic lipase activity. Intragastric administration of VLE to mice led to a significant decrease in the body weight, tissue fat accumulation, levels of cholesterol, low-density lipoprotein and triglyceride compared to mice fed with high fat diet. We also found a lower level of neuropeptide-Y (NPY) in the serum and hypothalamus and a higher level of fibroblast growth factor 15 in mice supplemented with VLE. These results suggested that VLE regulates both the NPY-mediated pathway and the bile acid-FGF15 pathway to control energy metabolism and body weight gain. The composition of VLE was further investigated by a targeted metabolomics approach, which identified 21 compounds including phenolic acids, flavones, flavanols, flavanones, coumarins, and stilbenes. Taken together, we demonstrated the capacity of grape leaves in reducing obesity, which could be mediated by NPY and bile acids. Identification of putative active compounds in VLE also open the path for further studies to determine their effectiveness individually to treat obesity.

Bile salt hydrolase (BSH)-producing bacteria are negatively related to the body weight gain and energy storage of the host. We aimed to obtain a novel BSH-producing strain with excellent anti-obesity effect and explained its mechanism. Here, we selected a strain named Lactiplantibacillus plantarum H-87 (H-87) with excellent ability to hydrolyze glycochenodeoxycholic acid (GCDCA) and tauroursodeoxycholic acid (TUDCA) in vitro from 12 lactobacilli, and evaluated its anti-obesity effect in high-fat diet (HFD)-fed C57BL/6J mice. The results suggested that H-87 could inhibit HFD-induced body weight gain, fat accumulation, liver lipogenesis and injury, insulin resistance and dyslipidemia. In addition, H-87 could colonize in the ileum and hydrolyze GCDCA and TUDCA, reflected as changes in the concentrations of GCDCA, TUDCA, CDCA and UDCA in the ileum or liver. Furthermore, the study identified that H-87 reduced TUDCA and GCDCA levels in the ileum, which decreased the GLP-1 secretion by L cells to alleviate insulin resistance in HFD-fed mice. Furthermore, H-87 increased the CDCA level in the ileum and liver to activate FXR signaling pathways to inhibit liver lipogenesis in HFD-fed mice. In addition, the decrease of intestinal conjugated bile acids (TUDCA and GCDCA) also increased fecal lipid content and decreased intestinal lipid digestibility. In conclusion, H-87 could inhibit liver fat deposition, insulin resistance and lipid digestion by changing bile acid enterohepatic circulation, and eventually alleviate HFD-induced obesity.

Aims Infantile eczema, usually coupled with a range of hypersensitive phenotypes, has come into notice with its rising prevalence and unclear pathogenesis. Recent studies show close ties between eczema and an infant’s intestinal flora. To gain a further understanding of the interactions between microbiota and eczema, we studied the breast milk flora as a new factor and present the links among breast milk flora, infant intestinal flora and infantile eczema through a cohort study in Northeast China. Methods and Results Fifty‐two families were recruited with either an eczema or healthy infant younger than 6 months. Analysis and predictions using amplicon sequencing of microbiota found that Bifidobacterium and Bacteroidetes were enriched in healthy‐ and eczema‐infant stools, respectively, consistent with previous reports. For breast milk flora, more ‘positive’ bacteria such as Akkermansia were enriched in breast milk from healthy infants’ mothers. Further, higher bacterial delivery efficiencies were found in pairs of breast milk flora and infants’ stool flora of families with eczema‐infants compared with families with healthy infants. Bacteroidetes, a widely known indicator of eczema, was found delivered more in eczema pairs. Further metagenomic predictions revealed that the breast milk microbiota participated significantly less in metabolism and immune system pathways, particularly in antigen processing and presentation and in Th17 cell‐related pathways. Conclusions In conclusion, as with other components of breast milk, the breast milk microbiota closely associates with infants’ health via mother‐infant bacterial delivery and metabolic functions. Significance and Impact of Study Our research aimed to fill the gap between the eczema and breast milk flora and describe the connections among breast milk and intestinal flora and eczema.

Aims The purpose of this study was to investigate the characteristics of gut microbiota of children with obesity in Harbin, China and to screen anti‐obesity strains in vitro and in vivo. Methods and Results The gut microbiota of children with obesity and normal‐weight children were investigated by high‐throughput sequencing, and based on the different composition in gut microbiota, the strains with potential anti‐obesity properties were screened in vitro and in vivo. Compared with normal‐weight children, the Firmicutes to Bacteroidetes ratio in children with obesity decreased. Moreover, the relative abundances of Lactobacillus and Bifidobacterium in children with obesity were decreased, while the relative abundance of Akkermansia increased. After a series of screening in vitro and in vivo, nine strains were found inhibiting the body weight gain of HFD‐fed mice, of which two strains showed significant effects (P<0.05). Conclusions There were significant changes in gut microbiota of children with obesity from Harbin, China. The obtained strains showed obvious anti‐obesity effects, and the screening methods used in this study were effective. Significance and Impact of Study This study enriched the research results on the characteristics of gut microbiota of children with obesity in different regions of the world. Moreover, we established a new and effective method for screening anti‐obesity strains, and obtained effective strains.