2'-Fucosyllactose alleviates OVA-induced food allergy in mice by ameliorating intestinal microecology and regulating the imbalance of Th2/Th1 proportion.

Food allergy (FA) has become a prominent problem in public health. 2'-Fucosyllactose (2'-FL) was reported to alleviate FA symptoms; however, the regulatory mechanism is still unclear. This study evaluated the 2'-FL antiallergic potential in an ovalbumin (OVA)-sensitized mouse model and explored the systemic effects of 2'-FL on gut microecology and the intestinal immune barrier. The results showed that 2'-FL alleviated allergy symptoms, decreased serum allergic indicator levels, enhanced the intestinal barrier, and attenuated low-grade inflammation. The up-regulation of G protein-coupled receptors (GPRs) was associated with higher levels of short-chain fatty acids (SCFAs) in 2'-FL intervention mice. 2'-FL also improved the intestinal microbiota diversity and increased the abundance of Akkermansia, Lachnospiraceae UCG-006, and Ruminococcaceae while suppressing Muribaculaceae, Desulfovibrionaceae, and Erysipelotrichaceae. Additionally, 2'-FL ameliorated the imbalance of Th2/Th1, mainly by decreasing Th2-type immune response and enhanced CD4 + Foxp3 + Treg immunoreaction. These results suggest that 2'-FL restores intestinal barrier defects, gut microbiota disorder, and immune impairment while alleviating ovalbumin-induced allergic symptoms in FA mice.

Ameliorating Effects of Bifidobacterium longum subsp. infantis FB3-14 against High-Fat-Diet-Induced Obesity and Gut Microbiota Disorder.

Obesity has emerged as one of the most prevalent chronic diseases worldwide. Our study was conducted to investigate the anti-obese potential of novel probiotic Bifidobacterium longum subsp. infantis FB3-14 (FB3-14) and the underlying molecular mechanisms in high-fat diet (HFD)-fed mice. The results demonstrated that an 8-week FB3-14 intervention significantly suppressed the HFD-induced body and fat weight gain and abnormal alterations of the serum lipid parameter, restoring the levels of cholesterol (4.29 mmol/L) and low-density lipoprotein cholesterol (3.42 mmol/L). FB3-14 treatment also attenuated adipocyte expansion, hepatic injury, and low-grade systemic inflammation and restored the expressions of lipid-metabolism-related genes, including Hsl, Leptin, and Adiponectin. Furthermore, FB3-14 was observed to reduce the Firmicutes/Bacteroidetes ratio in obese mice; increase the abundance of Akkermansia muciniphila, unclassified_Muribaculaceae, Lachnospiraceae_NK4A136_group, and Bifidobacterim; and upregulate G protein-coupled receptor41 associated with higher levels of butyric acid. These results indicate the protective effectiveness of FB3-14 in HFD-driven obesity and gut microbiota disorders, highlighting the promising potential of FB3-14 as a functional nutrition supplement.

Tartary Buckwheat (Fagopyrum tataricum) Ameliorates Lipid Metabolism Disorders and Gut Microbiota Dysbiosis in High-Fat Diet-Fed Mice.

Jinqiao II, a newly cultivated variety of tartary buckwheat (Fagopyrum tataricum), has been reported to exhibit a higher yield and elevated levels of functional compounds compared to traditional native breeds. We aimed to investigate the potential of Jinqiao II tartary buckwheat to alleviate lipid metabolism disorders by detecting serum biochemistry, pathological symptoms, gene expression profiling, and gut microbial diversity. C57BL/6J mice were provided with either a normal diet; a high-fat diet (HFD); or HFD containing 5%, 10%, and 20% buckwheat for 8 weeks. Our results indicate that Jinqiao II tartary buckwheat attenuated HFD-induced hyperlipidemia, fat accumulation, hepatic damage, endotoxemia, inflammation, abnormal hormonal profiles, and differential lipid-metabolism-related gene expression at mRNA and protein levels in response to the dosages, and high-dose tartary buckwheat exerted optimal outcomes. Gut microbiota sequencing also revealed that the Jinqiao II tartary buckwheat elevated the level of microbial diversity and the abundance of advantageous microbes (Alistipes and Alloprevotella), lowered the abundance of opportunistic pathogens (Ruminococcaceae, Blautia, Ruminiclostridium, Bilophila, and Oscillibacter), and altered the intestinal microbiota structure in mice fed with HFD. These findings suggest that Jinqiao II tartary buckwheat might serve as a competitive candidate in the development of functional food to prevent lipid metabolic abnormalities.

Differential regulation and preventive mechanisms of green tea powder with different quality attributes on high-fat diet-induced obesity in mice.

Tea powder has been reported to have some physiological functions. However, there is no report on whether there are differences in the active ingredients of tea powder with different qualities and whether there are different prebiotic mechanisms. This study was aimed to investigate the effects of different qualities of tea powder on preventing obesity from different aspects, namely antioxidation, inflammation, lipid-lowering, and intestinal flora, using an obesity mouse model. The results showed that all three types of tea powder with different qualities could reduce body weight and decrease serum TC, TG, and LDL-C. However, tea powder with different quality attributes exhibited diverse modulatory effects and mechanisms. Tender tea powder contained more tea polyphenols, and it had a better effect on improving oxidative stress. Tender tea powder significantly decreased the abundances of Blautia, Bilophila, and Oscillibacter, and increased the abundances of Alloprevotella, Lachnoclostridium, Romboutsia, and Ruminococcaceae_UCG-004. Coarse tea powder contained more dietary fiber, and had a better effect on reducing the food intake and improving lipid metabolism, which could reduce lipid synthesis and increase lipid ß-oxidation. Coarse tea powder significantly decreased the abundance of Dubosiella and increased the abundances of the Lachnospiraceae_NK4A136 group and Coriobacteriaceae_UCG-002. Our findings provide a theoretical reference for the comprehensive utilization of tea powder.

Current Advances in Structure-Function Relationships and Dose-Dependent Effects of Human Milk Oligosaccharides.

HMOs (human milk oligosaccharides) are the third most important nutrient in breast milk. As complex glycans, HMOs play an important role in regulating neonatal intestinal immunity, resisting viral and bacterial infections, displaying anti-inflammatory characteristics, and promoting brain development. Although there have been some previous reports of HMOs, a detailed literature review summarizing the structure-activity relationships and dose-dependent effects of HMOs is lacking. Hence, after introducing the structures and synthetic pathways of HMOs, this review summarizes and categorizes identified structure-function relationships of HMOs. Differential mechanisms of different structural HMOs utilization by microorganisms are summarized. This review also emphasizes the recent advances in the interactions between different health benefits and the variance of dosage effect based on in vitro cell tests, animal experiments, and human intervention studies. The potential relationships between the chemical structure, the dosage selection, and the physiological properties of HMOs as functional foods are vital for further understanding of HMOs and their future applications.

2'-Fucosyllactose Ameliorates Oxidative Stress Damage in d-Galactose-Induced Aging Mice by Regulating Gut Microbiota and AMPK/SIRT1/FOXO1 Pathway.

The imbalance of reactive oxygen species is the main cause in aging, accompanied by oxidative stress. As the most abundant in human milk oligosaccharides (HMOs), 2'-Fucosyllactose (2'-FL) has been confirmed to have great properties in immunity regulation and anti-inflammatory. The research on 2'-FL is focused on infants currently, while there is no related report of 2'-FL for the elderly. A d-galactose-induced accelerated aging model was established to explore the protective effect of 2'-FL on the intestines and brain in mice. In this study, 2'-FL significantly reduced oxidative stress damage and inflammation in the intestines of aging mice, potentially by regulating the sirtuin1 (SIRT1)-related and nuclear factor E2-related factor 2 (Nrf2) pathways. In addition, 2'-FL significantly improved the gut mucosal barrier function and increased the content of short-chain fatty acids (SCFAs) in the intestine. The gut microbiota analysis indicated that 2'-FL mainly increased the abundance of probiotics like Akkermansia in aging mice. Moreover, 2'-FL significantly inhibited apoptosis in the brains of aging mice, also increasing the expression of SIRT1. These findings provided a basis for learning the benefits of 2'-FL in the aging process.

Dose-Dependent Beneficial Effects of Tryptophan and Its Derived Metabolites on Akkermansia In Vitro: A Preliminary Prospective Study.

Akkermansia muciniphila, a potential probiotic, has been proven to lessen the effects of several diseases. As established, the relative abundance of Akkermansia is positively correlated with tryptophan metabolism. However, the reciprocal interaction between tryptophan and Akkemansia is still unclear. Herein, for the first time, the possible effects of tryptophan and its derived metabolites on A. muciniphila were preliminarily investigated, including growth, physiological function, and metabolism. Obtained results suggested that 0.4 g/L of tryptophan treatment could significantly promote the growth of A. muciniphila. Notably, when grown in BHI with 0.8 g/L of tryptophan, the hydrophobicity and adhesion of A. muciniphila were significantly improved, potentially due to the increase in the rate of cell division. Furthermore, A. muciniphila metabolized tryptophan to indole, indole-3-acetic acid, indole-3-carboxaldehyde, and indole-3-lactic acid. Indoles produced by gut microbiota could significantly promote the growth of A. muciniphila. These results could provide a valuable reference for future research on the relationship between tryptophan metabolism and A. muciniphila.

Protection of Galacto-Oligosaccharide against E. coli O157 Colonization through Enhancing Gut Barrier Function and Modulating Gut Microbiota.

Galacto-oligosaccharide (GOS) has been added to infant formula as prebiotics and can bring many benefits to human health. This study proved the effect of GOS in prevention and alleviation against E. coli O157 invasion and colonization and the mechanism behind this was explored in a mice model. The results showed that the expression of Muc2 and Occlaudin were both significantly down-regulated (p < 0.05) by E. coli O157 infection, while GOS alleviated this phenomenon, which means that GOS can reduce the colonization of E. coli O157 by enhancing the gut barrier function. Through the determination of inflammatory cytokines, we found that GOS can relieve inflammation caused by pathogens. At the same time, GOS can promote the growth of probiotics such as Akkermansia, Ruminococcaceae and Bacteroides, thus modulating microorganism environments and improving short chain fatty acid (SCFA) levels in the intestine. This study provides an explanation for the mechanism behind the protection of GOS against pathogen infection.

The Protective Effects of 2'-Fucosyllactose against E. Coli O157 Infection Are Mediated by the Regulation of Gut Microbiota and the Inhibition of Pathogen Adhesion.

As the richest component in human milk oligosaccharides (HMOs), 2'-fucosyllactose (2'-FL) can reduce the colonization of harmful microbiota in vivo, thus lowering the risk of infection; however, the mechanism for this is still unclear. In this study, a model of Escherichia coli O157 infection in healthy adult mice was established to explore the effect of 2'-FL intervention on E. coli O157 colonization and its protective effects on mice. The results showed that 2'-FL intake reduced E. coli O157 colonization in mice intestine by more than 90% (p < 0.001), and it also reduced intestinal inflammation, increased the content of fecal short-chain fatty acids, and enhanced intestinal barrier function. These beneficial effects were attributed to the increased expression of mucins such as MUC2 (increased by more than 20%, p < 0.001), and inhibition of E. coli O157 cell adhesion (about 30% reduction, p < 0.001), and were associated with the modulation of gut microbiota composition. 2'-FL significantly increased the abundance of Akkermansia, a potential probiotic, which may represent the fundamental means by which 2'-FL enhances the expression of mucin and reduces the colonization of harmful bacteria. The current study may support the use of 2'-FL in the prevention of foodborne pathogen infections in human.