2′-Fucosyllactose Increases the Abundance of Blautia in the Presence of Extracellular Fucosidase-Possessing Bacteria

Abstract

Blautia is a genus of anaerobic bacteria that is widely distributed in the mammalian gut. Recently, an increasing body of research has demonstrated a link between this genus and human health, suggesting applications as a novel probiotic strain. Moreover, we have previously shown that 2′-fucosyllactose (2′-FL), a major component of human milk oligosaccharides, increases the relative abundance of Blautia sp., particularly Blautia wexlerae, in the cultured fecal microbiota of healthy adults using a pH-controlled single-batch fermenter. However, the effects of 2′-FL on Blautia proliferation vary among individuals. In this study, we assessed the impact of the intrinsic gut microbiota on the prebiotic effects of 2′-FL. Metagenomic analysis of feces collected from all donors showed that the homolog of the intracellular GH95 α-l-fucosidase gene was considerably enriched in two non-responders (individuals who showed no increase in Blautia proliferation), whereas the homologous genes encoding extracellular α-l-fucosidase were more abundant in responders, suggesting that lactose and fucose released into the environment could be substrates mediating the growth of Blautia. In vitro assays confirmed the ability of B. wexlerae to utilize the two carbohydrates but not 2′-FL. We also observed that B. wexlerae utilized fucose released from 2′-FL by Bifidobacterium bifidum, which possessed extracellular GH95 α-l-fucosidase, in co-cultures of these two organisms. Finally, increasing the proportion of extracellular GH95 by the addition of a B. bifidum strain led to Blautia proliferation by 2′-FL in fecal cultures of the two non-responders. These findings provided valuable perspectives on individualized nutritional approaches to properly control the gut microbiota. Future clinical trials are needed to obtain further insights into the characteristics of responders vs. non-responders.

Ex vivo impact of human milk oligosaccharides and lactose on microbiome in infants with cow's milk protein allergy

“…B. obeum and R. gnavus produce propionate via the propanediol pathway starting from fucose, a major constituent of 2'-FL [50]. The involvement of this pathway is further corroborated by the earlier observation that 2'-FL stimulatesBlautia species in presence of extracellular fucosidase-possessing bacteria [51]. R. gnavus has been shown to be the exclusive Lachnospiraceae representative in 2 month-old breastfed infants [52], further suggesting a key role of this species and the propanediol pathway in HMO fermentation.…”

Effects of 2'‐fucosyllactose on the composition and metabolic activity of intestinal microbiota from piglets after in vitro fermentation

“…60 From in vitro co-culture assays, Blautia, and particularly Blautia wexlerae, has been reported to utilize fucose released from 2'-FL by Bifidobacterium bifidum, which 2'-Fucosyllactose and intestinal microbiota www.soci.org possessed extracellular GH95 ⊍-L-fucosidase. 60 In this study, the abundance of Megasphaera, a common lactate-utilizing bacteria in the gut, was increased in the FOS group, which could convert lactate to propionate through the acrylate pathway. 51 A previous study reported that, under carbon-limited steady-state conditions, lactate was converted to butyrate rather than propionate by Megasphaera.…”

“…Notably, 2'‐FL fermentation increased the abundance of the genus Blautia in the jejunum, suggesting that Blautia might be a specialized degrader of 2'‐FL. It is reported that fucose from the degradation of 2'‐FL by the microbiota was released into intestinal tract as substrates mediating the growth of Blautia 60 . From in vitro co‐culture assays, Blautia , and particularly Blautia wexlerae , has been reported to utilize fucose released from 2'‐FL by Bifidobacterium bifidum , which possessed extracellular GH95 α ‐ l ‐fucosidase 60 .…”

“…It is reported that fucose from the degradation of 2'‐FL by the microbiota was released into intestinal tract as substrates mediating the growth of Blautia 60 . From in vitro co‐culture assays, Blautia , and particularly Blautia wexlerae , has been reported to utilize fucose released from 2'‐FL by Bifidobacterium bifidum , which possessed extracellular GH95 α ‐ l ‐fucosidase 60 . In this study, the abundance of Megasphaera , a common lactate‐utilizing bacteria in the gut, was increased in the FOS group, which could convert lactate to propionate through the acrylate pathway 51 .…”

Structure and function of microbial α-l-fucosidases: a mini review

“…The capability of removing α- l -fucosyl residues from free oligosaccharides and glycoconjugates conferred fucosidase-possessing microbes a competitive advantage in mucin glycan foraging [ 14 ], and in turn help maintain intestinal homeostasis [ 76 , 77 ]. Fucosidases from commensal bacteria also play a role in cross-feeding with other members of the gut microbiota [ 78 , 79 ] or enteric pathogens such as Salmonella enterica serovar Typhimurium, Clostridium difficile , [ 80 ], Campylobacter jejuni [ 81 , 82 ] and other pathogens [ 83 ] facilitating their infection. Recently, α- l -fucosidases from the GH29 family were identified and characterised from the metagenome of faecal samples of breastfed infants.…”