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.

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.

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.

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.

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.

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.