Human milk oligosaccharides and infant gut microbiome in Mongolian mother-infant dyads.

Human milk oligosaccharides (HMO) play crucial roles in establishing a healthy gut microbiota in breastfed infants. Many studies have been conducted using samples collected in different areas with varying lifestyles to examine the relationships between milk HMO, infant gut microbiota, and microbial HMO consumption in feces. The present study analyzed the tripartite relationship using samples obtained from Mongolian mothers and infants living in herder and urban environments, a population underrepresented in previous research.

Uptake of fucosylated type I human milk oligosaccharide blocks by subsp. .

Unlabelled: Human milk oligosaccharides (HMOs) are uniquely rich in the type 1 building block disaccharide lacto--biose I (LNB; Galβ1,3GlcNAc), as compared to other mammals. Most HMOs are fucosylated, for example, α1,2 and α1,4 fucosylations on LNB blocks, resulting in H type 1 (H1) and Lewis a (Le) epitopes, respectively. The dominance of in breastfed infant guts hinges on the efficient uptake of HMOs by specific ATP-binding cassette (ABC) importers.

Suppression of fecal phenol production by oral supplementation of sesamol: inhibition of tyrosine phenol-lyase by sesamol.

Phenol is produced from dietary L-tyrosine by the action of tyrosine phenol-lyase (TPL) of gut bacteria and contributes to various physiological disorders, including skin diseases, certain cancers, and kidney dysfunction. We found that oral supplementation of sesamol (36 or 180 μg mL) for 14 days in mice significantly suppressed fecal phenol production. Fecal microbiota structure analysis in sesamol-supplemented and control groups revealed that their overall microbiota structures were indistinguishable.

competition with strains impairs potentially pathogenic growth of on 2'-fucosyllactose.

Fortifying infant formula with human milk oligosaccharides, such as 2'-fucosyllactose (2'-FL), is a global trend. Previous studies have shown the inability of pathogenic gut microbes to utilize 2'-FL. However, the present study demonstrates that the type strain (JCM 1290) of , a pathobiont species often more prevalent and abundant in the feces of C-section-delivered infants, exhibits potentially pathogenic growth on 2'-FL.

An improved temperature-sensitive shuttle vector system for scarless gene deletion in human-gut-associated species.

is a prevalent bacterial taxon in the human gut that comprises over 10 (sub)species. Previous studies suggest that these species use evolutionarily distinct strategies for symbiosis with their hosts. However, the underlying species-specific mechanisms remain unclear due to the lack of efficient gene knockout systems applicable across different species.

Human gut-associated species salvage exogenous indole, a uremic toxin precursor, to synthesize indole-3-lactic acid via tryptophan.

Indole in the gut is formed from dietary tryptophan by a bacterial tryptophan-indole lyase. Indole not only triggers biofilm formation and antibiotic resistance in gut microbes but also contributes to the progression of kidney dysfunction after absorption by the intestine and sulfation in the liver. As tryptophan is an essential amino acid for humans, these events seem inevitable.

Human Milk Oligosaccharide Utilization in Intestinal Bifidobacteria Is Governed by Global Transcriptional Regulator NagR.

Bifidobacterium longum subsp. is a prevalent beneficial bacterium that colonizes the human neonatal gut and is uniquely adapted to efficiently use human milk oligosaccharides (HMOs) as a carbon and energy source. Multiple studies have focused on characterizing the elements of HMO utilization machinery in B.

Priority effects shape the structure of infant-type Bifidobacterium communities on human milk oligosaccharides.

Bifidobacteria are among the first colonizers of the infant gut, and human milk oligosaccharides (HMOs) in breastmilk are instrumental for the formation of a bifidobacteria-rich microbiota. However, little is known about the assembly of bifidobacterial communities. Here, by applying assembly theory to a community of four representative infant-gut associated Bifidobacterium species that employ varied strategies for HMO consumption, we show that arrival order and sugar consumption phenotypes significantly affected community formation.

A simple method that enhances minority species detection in the microbiota: 16S metagenome-DRIP (Deeper Resolution using an Inhibitory Primer).

16S rRNA gene-based microbiota analyses (16S metagenomes) using next-generation sequencing (NGS) technologies are widely used to examine the microbial community composition in environmental samples. However, the sequencing capacity of NGS is sometimes insufficient to cover the whole microbial community, especially when analyzing soil and fecal microbiotas. This limitation may have hampered the detection of minority species that potentially affect microbiota formation and structure.

Diversification of a Fucosyllactose Transporter within the Genus .

Human milk oligosaccharides (HMOs), which are natural bifidogenic prebiotics, were recently commercialized to fortify formula milk. However, HMO assimilation phenotypes of bifidobacteria vary by species and strain, which has not been fully linked to strain genotype. We have recently shown that specialized uptake systems, particularly for the internalization of major HMOs (fucosyllactose [FL]), are associated with the formation of a -rich gut microbial community.