KitoZyme (Belgium)

Abstract BackgroundTo develop a dedicated database and food frequency questionnaire (FFQ) allowing detailed dietary fiber (DF) intake estimation including prebiotic (oligo)saccharides.MethodsA repertoire of DF detailing total, soluble DF, insoluble DF and prebiotic (oligo)saccharides (inulin-type fructans, fructo-oligosaccharides and galacto-oligosaccharides) in food products consumed in Europe has been established on basis of the German and Canadian databases and published data. A 12-month FFQ was developed and submitted to 15 healthy volunteers (mean age: 21 yrs; mean BMI: 22 kg/m2) from the FiberTAG study (https://www.fibertag.eu/).ResultsThe FiberTAG repertoire details DF and prebiotic (oligo)saccharides in 283 food items allocated into 4 categories and 15 subcategories. The FiberTAG FFQ consists in 302 items regrouped in 4 high DF-containing food groups (vegetables including legumes, fruits including nuts and seed, cereal products and others), proposes intake frequency scales, photographs for portion size evaluation and considers the seasonal occurrence for vegetables or fruits. Our data in the tested population report a total DF intake of 38 g/d (1/3 of soluble and 2/3 of insoluble DF). Fructan and fructo-oligosaccharides intake, linked notably to condiments (garlic and onions) ingestion, reached 5 and 2 g/d, respectively, galacto-oligosaccharides intake level being lower (1 g/d).ConclusionsThe FiberTAG repertoire and FFQ are major tools for the evaluation of the total amount of DF including prebiotics. Their use can be helpful in intervention or observational studies devoted to analyze microbiota-nutrient interactions in different pathological contexts, as well as to revisit DF intake recommendations as part of healthy lifestyles considering specific DF.Trial registrationNCT03494491(clinicaltrials.gov)

Chitin-glucan (CG) represents a natural carbohydrate source for certain microbial inhabitants of the human gut and may act as a prebiotic for a number of bacterial taxa. However, the bifidogenic activity of this substrate is still unknown. In the current study, we evaluated the ability of chitin-glucan to influence growth of 100 bifidobacterial strains belonging to those species commonly identified within the bifidobacterial communities residing in the infant and adult human gut. Such analyses were coupled with transcriptome experiments directed to explore the transcriptional effects of CG on Bifidobacterium breve 2L, which was shown to elicit the highest growth performance on this natural polysaccharide. In addition, an in vivo trial involving a rat model revealed how the colonization efficiency of this bifidobacterial strain was enhanced when the animals were fed with a diet containing CG. Altogether our analyses indicate that CG is a valuable novel prebiotic compound that may be added to the human diet in order to re-establish/reinforce bifidobacteria colonization in the mammalian gut.

Brettanomyces bruxellensis and the consequences of its development in wines are a continuous threat for wine quality. In this context, chitosan of fungal origin was introduced as a new tool to control B. bruxellensis in the context of winemaking. Recent studies have showed the impact of a fungal origin chitosan application on wines contaminated with B. bruxellensis, leading to the elimination of B. bruxellensis cells. In these studies, the chitosan preparation was added, the wine racked off after 10 days and the efficiency of the treatment was evaluated in a short delay after the treatment. This study focused on the evaluation of the impact of different addition protocols of an enological chitosan preparation on B. bruxellensis population evolution and volatile phenols content along the aging, up to 9 months. The results confirm the interest of fungal origin chitosan as a preventive tool to control B. bruxellensis in the context of wine aging.

<p style="text-align: justify;">This review treats of the possible use interest of chitin, chitosan and derivatives in enology. Chitosan and chitin are polysaccharide polymers containing more than 5 000 glucosamine and acetylglucosamine units, respectively, and their molecular weights are over one million Daltons. Chitin is found in fungi, arthropods and marine invertebrates. Commercially, chitin is derived from the exoskeletons of crustaceans (shrimp, crab and other shellfish). Chitosan is obtained from chitin by a deacetylation process. An alternative can be the obtention of chitin and chitosane derivatives from fungi source and has been developed by Kitozyme Firm.</p><p style="text-align: justify;">Chitin, the polysaccharide polymer from which chitosan is derived, is a cellulose-like polymer consisting mainly of unbranched chains of N-acetyl-D-glucosamine. Deacetylated chitin, or chitosan, is comprised of chains of D-glucosamine. When ingested, chitosan can be considered as a dietary fiber.</p><p style="text-align: justify;">The use of chitin, chitosan and derivatives should be favorable for differents aspects of wine production, in particular for : stabilization, clarification, deacidification, removal of heavy metals (lead, cadmium) or major metals (iron , copper), elimination of ochratoxin A, enzymes and pesticides.</p>