Digestive fates of soluble polysaccharides from marine macroalgae: involvement of the colonic microflora and physiological consequences for the host

Michel, Catherine; Macfarlane, G.T.

doi:10.1111/j.1365-2672.1996.tb03230.x

Cited by 79 publications

(75 citation statements)

References 114 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These activities largely depend on the molecular weight of the polymer (34) and the amount of sulfations along the polysaccharide chain, both factors which are modulated with specific microbial CAZymes and sulfatases (29). Indeed, health implications and concerns have been associated with the low-molecular-weight degradation products of carrageenan, which elicited ulcerative colitis in animal models (11,(35)(36)(37). Our screening for red algal galactan degrading gut microbes revealed B. thetaiotaomicron VPI-3731, which presented strong growth on carrageenan and must therefore contain one or more carrageenases.…”

Section: Discussionmentioning

confidence: 99%

“…The major matrix polysaccharides in the cell walls of red algaewhich are the most common dietary red seaweed polysaccharides consumed by humans and present in many processed foods (11,12)-are carrageenans (13), agars, and porphyran (14), and all contain sulfate esters that are absent in terrestrial plants. Furthermore, the sugar backbones can contain unique monosaccharides, such as the 3,6-anhydro-D-galactose present in the carrageenan of Chondrus crispus (Irish moss) and the 3,6-anhydro-L-galactose (LA) found in agars of Gelidium and Gracilaria spp.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Bacteria of the human gut microbiome catabolize red seaweed glycans with carbohydrate-active enzyme updates from extrinsic microbes

Hehemann

Kelly

Pudlo

et al. 2012

Proc. Natl. Acad. Sci. U.S.A.

275

250

View full text Add to dashboard Cite

Humans host an intestinal population of microbes—collectively referred to as the gut microbiome—which encode the carbohydrate active enzymes, or CAZymes, that are absent from the human genome. These CAZymes help to extract energy from recalcitrant polysaccharides. The question then arises as to if and how the microbiome adapts to new carbohydrate sources when modern humans change eating habits. Recent metagenome analysis of microbiomes from healthy American, Japanese, and Spanish populations identified putative CAZymes obtained by horizontal gene transfer from marine bacteria, which suggested that human gut bacteria evolved to degrade algal carbohydrates—for example, consumed in form of sushi. We approached this hypothesis by studying such a polysaccharide utilization locus (PUL) obtained by horizontal gene transfer by the gut bacterium Bacteroides plebeius . Transcriptomic and growth experiments revealed that the PUL responds to the polysaccharide porphyran from red algae, enabling growth on this carbohydrate but not related substrates like agarose and carrageenan. The X-ray crystallographic and biochemical analysis of two proteins encoded by this PUL, BACPLE_01689 and BACPLE_01693 , showed that they are β-porphyranases belonging to glycoside hydrolase families 16 and 86, respectively. The product complex of the GH86 at 1.3 Å resolution highlights the molecular details of porphyran hydrolysis by this new porphyranase. Combined, these data establish experimental support for the argument that CAZymes and associated genes obtained from extrinsic microbes add new catabolic functions to the human gut microbiome.

show abstract

Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

Bacteria of the human gut microbiome catabolize red seaweed glycans with carbohydrate-active enzyme updates from extrinsic microbes

Hehemann

Kelly

Pudlo

et al. 2012

Proc. Natl. Acad. Sci. U.S.A.

275

250

View full text Add to dashboard Cite

show abstract

“…Alginates, extracted using acid and alkali from brown seaweed, are widely used in small amounts in foods as gelling agents, thickeners, stabilisers or emulsifiers (Michel & Macfarlane, 1996). The majority of algal polysaccharides are resistant to mammalian gastrointestinal hydrolases and their digestion is dependent on microbial depolymerisation and fermentation in the large intestine.…”

mentioning

confidence: 99%

“…Alginates have potential for use as a`functional food', since the production of b-elimination products by bacterial alginate-degrading enzymes may increase the growth of beneficial Bacteroides species of bacteria in the gut (Michel & Macfarlane, 1996). Guar gum (GG) produces the highest viscosity of any natural gum (BeMiller & Whistler, 1996), and is a galactomannan composed of a main chain of 1,4 b-D-mannopyranosyl with single unit a-D-galactopyranosyl branches.…”

mentioning

confidence: 99%

Comparative gastrointestinal and plasma cholesterol responses of rats fed on cholesterol-free diets supplemented with guar gum and sodium alginate

Seal

Mathers

2001

Br J Nutr

View full text Add to dashboard Cite

The present study investigated the digestion and cholesterol-lowering effects of the watersoluble NSP guar gum (GG) and sodium alginate (SA) in laboratory animals. Groups of five male Wistar strain rats were fed semi-purified cholesterol-free diets containing 0, 50 or 100 g NSP source/kg for 21 d which comprised a 14-d adaptation period followed by a 7-d balance period. Weight gain over the balance period and food conversion ratio decreased linearly with increasing NSP intake (P 0´006 and P 0´07 respectively). DM digestibility decreased with increasing NSP intake P 0´001 and this effect was greater for SA-containing diets compared with GG-containing diets P 0´001X At the lower inclusion rate, 0´9±1´0 of the additional NSP was digested, but this value fell to 0´8 for both NSP sources at the 100 g/kg inclusion rate, implying that the capacity for near complete digestion of the test NSP had been exceeded. Intestinal tissue mass was increased in response to inclusion of both NSP sources. Caecal digesta pH decreased linearly with additional GG, but increased slightly with consumption of SA. Total caecal short-chain fatty acid concentrations (mmol/g caecal contents) increased markedly with 50 g GG/kg but did not increase further with 100 g GG/kg, and were slightly lower than control values in rats consuming SA. Plasma cholesterol concentration fell linearly P 0´03 with increasing NSP in the diet and the effect was similar for both GG and SA. Total output of faecal bile acids rose in rats fed 50 g GG/kg and 50 g SA/kg (59 mmol/7 d v. 24 mmol/7 d for control rats) with no further increase at the higher inclusion rate. These results show that SA has a strong hypocholesterolaemic effect in rats which is similar to that of GG, and that this effect is most likely to be mediated through an interruption in the entero-hepatic circulation of bile acids and not through increased hepatic supply of propionate from fermentation of the NSP in the large bowel.

show abstract

“…Thus, the value reported here gives support to those findings. The values found for both the seaweed extract and chitosan were significantly higher than those described for fibre from land plants, which are generally in the range of 1-2.4 Eq.kg -1 (Michel and Macfarlane, 1996;Rupérez and Saura-Calixto, 2001). The values for chitosan can be explained by its high charge density, one positive charge for each glycosamine unit (Craveiro et al, 1999).…”

Section: Cation Exchange Capacitymentioning

confidence: 92%

Physiological and physico-chemical characterization of dietary fibre from the green seaweed Ulva fasciata Delile

et al. 2009

View full text Add to dashboard Cite

This work aims to assess the potential of the green seaweed Ulva fasciata Delile as an alternative source of dietary fibre (DF). Total DF content was determined, some of its physico-chemical properties described and the physiological effects of U. fasciata meal on rats fed a hypercholesterolemic diet were investigated. U. fasciata may be considered a potential alternative source of DF with a total content of about 400 g.kg -1 (dry basis) and interesting physico-chemical properties: water retention capacity of 8.74 g/water.g -1 dry sample (seaweed meal) and 0.90 (seaweed carbohydrate extract), lipid adsorption capacity of 4.52 g/oil.g -1 dry sample (seaweed meal) and 5.70 (seaweed carbohydrate extract), intrinsic viscosity of 2.4 dl.g -1 (seaweed carbohydrate extract) and cation exchange capacity of 3.51 Eq.kg -1 (seaweed carbohydrate extract). The diet containing seaweed meal was able to keep rats' total cholesterol (TC) down without causing any undesirable increase in LDL-C fraction. No evidence of toxic and/or antinutritional components in the seaweed meal was detected. Rats showed a fecal volume much greater (13 g) than that fed on cellulose diet (7 g) (p < 0.05). These properties confer on the seaweed the potential to be used in food technology for the acquisition of low-calorie food and might be important in body weight control, reduction of blood TC and LDL-C as well as in prevention of gastrointestinal diseases.

show abstract

Digestive fates of soluble polysaccharides from marine macroalgae: involvement of the colonic microflora and physiological consequences for the host

Cited by 79 publications

References 114 publications

Bacteria of the human gut microbiome catabolize red seaweed glycans with carbohydrate-active enzyme updates from extrinsic microbes

Bacteria of the human gut microbiome catabolize red seaweed glycans with carbohydrate-active enzyme updates from extrinsic microbes

Comparative gastrointestinal and plasma cholesterol responses of rats fed on cholesterol-free diets supplemented with guar gum and sodium alginate

Physiological and physico-chemical characterization of dietary fibre from the green seaweed Ulva fasciata Delile

Contact Info

Product

Resources

About