Characterization of fructooligosaccharide metabolism and fructooligosaccharide-degrading enzymes in human commensal butyrate producers

Abstract

Butyrate produced by gut microbiota has multiple beneficial effects on host health, and oligosaccharides derived from host diets and glycans originating from host mucus are major sources of its production. A significant reduction of butyrate-producing bacteria has been reported in patients with inflammatory bowel diseases and colorectal cancers. Although gut butyrate levels are important for host health, oligosaccharide metabolic properties in butyrate producers are poorly characterized. We studied the metabolic properties of fructooligosaccharides (FOSs) and other prebiotic oligosaccharides (i.e. raffinose and xylooligosaccharides; XOSs) in gut butyrate producers. 1-Kestose (kestose) and nystose, FOSs with degrees of polymerization of 3 and 4, respectively, were also included. Fourteen species of butyrate producers were divided into four groups based on their oligosaccharide metabolic properties, which are group A (two species) metabolizing all oligosaccharides tested, group F (four species) metabolizing FOSs but not raffinose and XOSs, group XR (four species) metabolizing XOSs and/or raffinose but not FOSs, and group N (four species) metabolizing none of the oligosaccharides tested. Species assigned to groups A and XR are rich glycoside hydrolase (GH) holders, whereas those in groups F and N are the opposite. In total, 17 enzymes assigned to GH32 were observed in nine of the 14 butyrate producers tested, and species that metabolized FOSs had at least one active GH32 enzyme. The GH32 enzymes were divided into four clusters by phylogenetic analysis. Heterologous gene expression analysis revealed that the GH32 enzymes in each cluster had similar FOS degradation properties within clusters, which may be linked to the conservation/substitution of amino acids to bind with substrates in GH32 enzymes. This study provides important knowledge to understand the impact of FOS supplementation on the activation of gut butyrate producers. Abbreviations: SCFA, short chain fatty acid; FOS, fructooligosaccharide; XOS, xylooligosaccharide; CAZy, Carbohydrate Active Enzymes; CBM, carbohydrate-binding module; PUL, polysaccharide utilization locus; S6PH sucrose-6-phosphate hydrolase.

Oligosaccharide Metabolism and Lipoteichoic Acid Production in Lactobacillus gasseri and Lactobacillus paragasseri

“…GH32 enzymes in the strains were sucrose-6-phosphate hydrolase (S6PH) and genes encoding phosphotransferase systems (PTSs) were adjacent to those encoding the S6PHs. S6PH is one of the most characterized enzymes to hydrolyze sucrose and kestose with or without phosphorylation in gut microbes [ 3 ]. Alignment of amino acid sequences of the GH32 proteins revealed that one of the GH32 proteins in L. gasseri (gene ID, 397) had one amino acid substitution (N to G) in the NDPNG motif (GDPNG) ( Figure 3 ), which is one of the key regions for its hydrolase activity of GH32 [ 31 ], whereas others conserved this motif.…”

“…They are usually commercialized as a mixture of degrees of polymerization (DP) of 3 and 4—i.e., 1-kestose [kestose, Fur (β2–1) Fur (β2–1α) Glc] and nystose [Fur (β2–1) Fur (β2–1) Fur (β2–1α) Glc]—respectively, with trace DP5 FOS, fructosylnystose. Among the components, kestose is a promising prebiotic for the stimulation of beneficial gut microbes, including bifidobacteria and butyrate producers [ 2 , 3 ]. Although the impact of oligosaccharides on the growth of beneficial gut microbes and probiotic strains is widely known, limited studies have addressed the impact of oligosaccharides, especially kestose, on the physiological properties of such bacteria.…”

Sequential Modulation of the Equine Fecal Microbiota and Fibrolytic Capacity Following Two Consecutive Abrupt Dietary Changes and Bacterial Supplementation

“…Concomitant with the fall in cellulolytic bacteria concentrations, our sequencing analysis revealed a decrease in the relative abundances of several potentially fibrolytic taxa, notably Lachnospiraceae ( Lachnospiraceae ND3007 group , Lachnospiraceae NK4A136 group , Lachnospiraceae UCG-008 ) [ 37 ]. The relative abundance of several fiber degraders such as the Eubacterium ruminantium group [ 38 ], the recently defined Agathobacter [ 39 , 40 ], and Roseburia [ 41 , 42 ] also fell at D2. The relative abundances of Spirochaetes and its lower phylogenetic levels dropped too.…”

Prebiotics and the Human Gut Microbiota: From Breakdown Mechanisms to the Impact on Metabolic Health

“…Although distinct in structure from Gram-negative systems, prominent Firmicutes and Actinobacteria members elaborate additional cell surface-associated systems for the utilisation of polysaccharides, which are often built around enzymes with catalytic domains, similar to those of Bacteroidetes [ 48 ]. Substrate-specific gene clusters targeting a variety of plant- and host-based glycans were identified in the genomes of Eubacterium rectale and Roseburia species as Gram-positive PUL (gpPUL) [ 54 , 68 , 69 ]. The gpPUL contain carbohydrate transport systems are mostly adenosine triphosphate (ATP)-binding cassette (ABC), major facilitator superfamily (MFS), and phosphoenolpyruvate-phosphotransferase system (PTS) transporters.…”